FX Royale Elite.Extensive review of some aspects of this rifle.
I am mindful that many shooters here are disdainful of reviews that are short on detail or smack of just advertisement blurb. I also realize that many don't like to read about every blade of grass someone has cut. I hope this report to be a fair compromise.

These results are relevant to the FX Elite rifle # 6007 of .25 calibre/ 6.35 mm. with Smooth Twist barrel shooting JSB Exact King 25.4 pellets and others as indicated..

This is a relatively new FX rifle model that shares some specifications with the FX Royale 500 . Numerous questions, suppositions, claims and opinions circulate in the airgun media regarding, in particular, the performance of the Smooth Twist ( ST ) barrels and their affect on pellet ballistics and accuracy in this line.

I have posted here of my rifles undoubted precision grouping ability a number of times:

http://www.network54.com/Forum/79537/message/1329610209/FX+Elite+ST+.25+cal+...+FX+Predators+and+FX+Kings+groups.+Instalment+%23+3.

This present present report addresses questions of :

1. Pellet spin-rate and its correspondence to barrel "rifling twist rate" and some implications.
2. The nature of physical pellet alterations as affected by the ST barrel configuration.
3. The influence of actual spin rate (as opposed to barrel twist rate ) and apparent alterations of pellet form on external ballistics; in particular it addresses the stability of pellet flight and of air resistance in flight and gives evidence based upon field testing.

Taking these three in turn:

1. The physical barrel "rifling twist rate" is nominally 1:16 inches, or an initial rate of one turn to 16 inches travel of the pellet. ... My tests of marked pellets shot through paper screens indicate an initial pellet in-flight spin rate of approximately one revolution in 70 to 80 inches of travel for JSB 25.4 gr King test pellets from this particular barrel at the particular test velocity. This test cannot be absolutely precise. But another conventionally rifled barrel, used as a control, and shot at the same velocity with the same pellets, shows consistent rates of 1:18 / 1:19 inches at muzzle for the test. This would be very close to the nominal twist rate for this barrel.

The first implication of this is that the test pellets shot through the ST barrel of this rifle do not have initial spin rates that correspond to the barrel's nominal left hand twist rate of 1:16". Their actual initial flight spin rate is approximately four and a half to five times slower than that of the actual rifling twist rate.

It should be emphasized that this should not necessarily be seen as being detrimental to field accuracy/ precision. On the contrary, the consistently excellent precision grouping, demonstrated here in previous research posts (as small as 0.25" at 52 yards and MOA at 100 yards), indicates otherwise (see referenced link). What it does do is to again raise the question as to the real role of an air rifle barrel's twist rate and its influence upon pellet stability. A diablo pellet is spin stabilized but also strongly drag stabilized, because of its shuttlecock shape, and most probably does not require the same spin rates that bullets require to prevent them from swapping ends.

[IMG][/IMG]

2. A reason for (1), above, is that the pellets are in fact "stripping" through the ST rifling but in doing so they follow the rifling sufficiently to pick up a consistent spin of the magnitude indicated. A close examination of recovered pellets after having been shot, seems to also verify this. Although the area ratio of the barrel's "lands" to the "grooves" of the "rifling" seems to be approximately in the ratio of 1:1:

[IMG][/IMG]

(Late Edit with added pic but of a .22 barrel with sleeve cover removed) : Outside of ST barrel muzzle showing the pressed lines that become the lands internally in the barrel.

[IMG][/IMG]

When shot through the barrel the pellets' heads and skirts have five conjoined "flats" that seem to have been swaged in stripping over the "lands". There is no visible evidence of markings that correspond to the "grooves" of the ST "rifling" seen in the above pic...

[IMG][/IMG]
[IMG][/IMG]

NOTE: There can be a distinct difference in the results emanating from the dynamics of shooting a pellet to those of one that has been merely pushed through the barrel (as is often reported in article reviews ). This would seem to be particularly so in this case of the ST barrel, given the great differences in the forces involved. With great care I managed to push some 0.25 pellets through the ST barrels in a way that shows the character of the barrel grooves as well as the lands; Edit: I had to encourage the barrel to rotate around the pellet to eventually get this result. I did not manage to be successful with the .22 barrel, every pushed pellet stripped with no evidence of the barrel grooves as high sections on the pellet.

[IMG][/IMG]
[IMG][/IMG]

Again, it would be a mistake to assume that this stripping would somehow result in reduced performance in accuracy, precision or velocity. None are truly compromised when judged by the field accuracy and results of precision grouping which I have attained so far.

3. In order to investigate the question of any possible positive and/ or negative influences of ST rifling on pellet flight characteristics, four approaches were undertaken namely 3a, 3b, 3c and 3d:

3a. A 50 to 100 yards "pellet drop test" comparison between the ST barrel Elite and a conventionally rifled BSA Hornet was made:

[IMG][/IMG]

This indicates that on a level playing field:
Given equal muzzle velocity of 880 fps and kinetic energy of 43.7 fpe ; with unselected pellets JSB Kings (best pellet for each rifle); with both rifles zeroed to 50 yards; under the same set of conditions; with only one group allowed to be shot at each range, not cherry picked from a number of groups; there was no obvious difference in drop from 50 yards to 100 yards ( 13.70 inches for the ST barrel and 13.75 inches for the conventionally rifled BSA barrel ); and no significant difference in grouping precision ( ctc 0.35 inches for both ST and BSA barrels at 50 yards, and 1.05 inches ctc ST barrel to 1.00 inch for the BSA Special Hornet barrel at 100 yd for 5 shot groups at each range ). ...

The implication of (3a) is that: at the specific MV 880 fps / Mach 0.78 at prevailing conditions, the air resistance of the same pellets shot from the two different barrels was similar, with no advantage in trajectory of the one over the other; and by implication, no differences in drag or ballistic coefficients. (However it will be seen in (3b) below, that this may not necessarily be the case at the higher muzzle velocity of 900 fps and Mach 0.80 when a velocity decay test over 55 yards was undertaken and a BC computed see (3b).

3b. A velocity decay test and computed ballistic coefficient were undertaken with 5 of JSB King pellets being shot over a chronograph at each distance of 18 inches and then at 55 yards at average velocity of 900 fps +/- 3 fps ST barrel and 898.2 fps +/- 2.5 fps for the BSA at 18 inches. The average velocities at 55 yards were 746 fps ST Elite barrel, 31.4 fpe, BC 0.0361 ( 0.0313 corrected to sea level ); and 760 fps, 32.6 fpe, BC 0.0407 ( 0.0352 corrected for sea level ) for the BSA Hornet. (Steve Woodwards BC calculator used).

This result indicates what appears to be a significant difference between the two rifles when the initial velocity of this pellet is increased to Mach 0.80. ... It is not in accord with the popular conjecture that the smoother rifling engravings on the ST barrel's projected pellets should necessarily automatically translate to an air resistance advantage in flight when compared to the engravings incurred from a conventionally rifled barrel. One school of reasoning in PB bullet ballistics is that the rifling engraving is of little consequence to air resistance as the boundary layer acts to moderate the possible influence.
This was a dramatic difference and so I shall repeat this test when time and ambient conditions permit to see if the results will be replicated.

3c. I have taken numerous slow motion video clips of pellets in flight from both the ST Elite barrel and the BSA Hornet's barrel. ...
My technique of taking movie clips through the scope sight is a personal adaptation of the method introduced to us all and made popular by Ted in Madison whose clips are well represented on YouTube.
My own innovations and techniques now allow for very reasonable flight analysis throughout virtually the whole of the pellet's journey. This has been enabled by tracking the pellet's flight from very close to the rifle out to quite long ranges.
JSB Kings and some other pellets' flight in calm and windy conditions show exceptional stability:

For Example: JSB Kings shot from the Elite and tracked to 50 yards in light wind showing beautifully stable flight:

http://smg.photobucket.com/albums/v392/Kyogle/?action=view¤t=FXSTElite3JSBKings51ydspigsilhouetteJan2012.mp4

And JSB Kings to 71 yards in relative calm:

http://smg.photobucket.com/albums/v392/Kyogle/?action=view¤t=FXElite5Kings71yardsJan2012.mp4

These are representative of many clips taken of JSB Kings in flight.
They all support the notion of the very stable flight of this pellet when projected from the Elite 6007 ST barrel regardless of the empirically established slow projected spin rate of 1: 70 to 1:80 inches, which varies dramatically from the 1:16 to 1:19 inch rates generally representative of the air rifle barrels; and of stable flight regardless of the pellets' surface and form changes that may have resulted from "stripping" through the ST 1:16 inch rifling.

Another example of arguably by far the best expanding hunting .25 cal pellet marketed today: FX Elite and 26 gr JSB Predator Polymag .25 hunting pellet to 50 yards showing excellent stability and accuracy in some wind:.

http://smg.photobucket.com/albums/v392/Kyogle/?action=view¤t=FXST25JSBPolymags3at51yardspigsilhouetteJan2012.mp4

3d. The fourth approach to establishing the stability status of flight, because of or in spite of the actual slow spin rate, was to examine the evidence of the apparent spatial attitude of the pellets to the target at the point of impact.
This pilot study was carried out at the extreme target range of 183 yards/ approx 167 metres and involved examining pellets that had impacted on a steel disc; on a very hard dead eucalyptus tree; that had penetrated some thick hard tree bark; or that had impacted hard ground.

Those that have impacted on the steel plough disc and flattened, seem to have obviously met it head on with point-on stability. (Late edit for picture insertion here)

[IMG][/IMG]

The steel disc target (below) with a five shot group, the best of three groups shot with an aim-off at the left edge of the disc of approx 12 inches to account for a light left to right breeze. The ctc group size is approx 54 mm or 2.12 inches or 1.11 MOA at the range of 183 yards.

[IMG][/IMG]

Close scrutiny will indicate the characteristic white dot of compressed paint where the heads of the pellets made first contact before the lead flattened and blasted away the surrounding paint - thus forming the typical point of impact signature markings. It should be noted that the pellets are descending from a flight mid-range trajectory apex of approximately 31 inches above the line of sight, and that the steel plough disc is slightly concave. Therefore there will naturally be a slightly off-centre head impact even from a perfectly stable non-gyrating flight.

This pellet was shot onto the very hard dead trunk of the eucalyptus tree above the target. It too has obviously remained stable and impacted "point-on".

[IMG][/IMG]

[IMG][/IMG]


This one was shot into bare ground at the same 183 yards off to one side of the target disc. It was the only one I recovered there and can be seen to have impacted dirt on the head indicating it too was still flying "point-on".

[IMG][/IMG]

The following picture shows a pellet that was shot into some very thick loose hard tree bark. It has penetrated one layer of bark and lodged in the second layer behind the first. It too has obviously retained its "point-on" attitude at 183 yards even after penetration of the first layer of dead bark.

[IMG][/IMG]

All of this supports an assertion that, despite or perhaps because of, the actual slow flight spin rate induced by the ST barrel format, the pellets are remaining stable to the range of 183 yards/ approx 167 metres. Further tests to longer range will be undertaken.

Initial velocity for these test shots was an average 915 fps which may be higher than ideal. Where indicated, performance comparisons are to a BSA Hornet which has been modified by John Bowkett of UK with installation of his own regulator and fill valve designs; barrel crowning; chamber preparation; and power increase to 45 to 50 fpe in .25 calibre; otherwise the barrel is a hammer forged BSA factory barrel as installed in the unregulated BSA Lonestar .25 rifles. This is an exceptional rifle by any standards.

In summary: To date the evidence I have supports the following in respect of the FX Elite S/N 6007 smooth twist barrel:

It seems as accurate as the best I have.

Actual pellet spin rate does not correspond to rifling twist rate and is about four to five times slower from this ST barrel. Accuracy/ grouping is excellent with the big 4 viz., JSB Kings, JSB Predator Polymags, Baracuda/ Kodiaks and Benjamin domes.

Pellets strip through the "rifling" and show no real evidence of the rifling's "grooves". In doing so they do pick up a relatively slow spin. The spin is apparently sufficient to stabilize the 4 popular pellets.

The actual but slow induced spin rate, combined with the drag stabilizing effects of the test diabolo pellets shape, are sufficient for precision grouping in some wind that approaches the best I have attained with conventional rifling at that range. .

The apparently more limited engraving of the ST rifling upon the test pellets does not appear to have any benefit in improving resistance to air friction in flight at a velocity of Mach 0.78 out to 100 yards as judged by pellet drop.

At an initial velocity of Mach 0.80 the velocity decay over 55 yards, was for some unknown reason, greater than that from the conventional rifled barrel when all other controllable factors were kept equal. (This deserves re-visiting and at even higher mach numbers ). This is somewhat at odds with the drop test results.

Slow motion videos indicate very stable pellet flight with no apparent precession, or spiral flight, for the JSB King and Polymag test pellets to the test ranges of 50 or 71 yards filmed .

JSB King pellets recovered at extreme range, 183 yards, show that they arrive at the POI with a "point-on" attitude - again indicating excellent flight stability in the prevailing light wind conditions.

Precision grouping in a light breeze to 183 yards is well within expectations with a 5 shot group of 2.12 inches ctc from a very limited number of 3 groups. For comparison, the best 5 shot group I have shot to date at that range is 1.45 inches ctc shooting 15.9 gr JSB Exact pellets in more perfect conditions. Very few groups have ever been shot at this specific range.

The sight was zeroed for the 183 yards tests with 172 clicks on the Bushnell 6500 scope set at 16X . Dave Eades' CG Ballistica Programme was used for all sight zero adjustments.

Link to my third post # 3 and which incorporates links to posts # 1 and # 2 for any who may be interested in the complete to date package:

http://www.network54.com/Forum/79537/message/1329610209/FX+Elite+ST+.25+cal+...+FX+Predators+and+FX+Kings+groups.+Instalment+%23+3.

I hope some have read to this point and enjoyed it ....... Best regards, Yrrah, Harry Fuller in OZ.

Thanks for the extensive testing and write up Harry, I learned alot.

Pellets strip through the "rifling" is this the reason ST barrels are limited more so that rifled barrels to 910 fps to maintain accuracy? It looks like anything over 910 or close to that the rifling may not work at all.

RogerV

.25 cal. All my guns are currently LW barrel. My groups are tight at 930 to 945fps. which for me is a better hunting velocity especially with preds. Might just be something in the ST vs LW. ST seems to be as accurate and maybe even more? However, maybe this is why the fliers come at higher velocity w/ST's.
Exceptional report, the very best I have ever seen. With specific information of such a report we all can make more educated decisions and apply this to our purchase of guns with ST and or LW or X barrel.
Well Done Sir!
Thanks Harry.

nt

my own real field experience and results with my one rifle and its present two barrels. Though I favour 880 fps the .25 cal is shooting 25.4 gr Kings and 26 gr Polymags to 930 fps in good air with excellent accuracy; and old Kodiaks to 860+ fps as its power limit. I really don't know what the results would be for the .25 at screaming velocities but never really expect accuracy to improve in the higher zone as you are aware from my past writing. ... I do know now that the .22 ST barrel will do well at even higher velocities with 18.1 gr JSB Exacts.

.22 ST barrel in the Elite shot at 55 yards/ 50 metres when sighting in at a club shoot.

[IMG][/IMG]

I am not really sure of the velocity but it had to be high as I had not altered the power from shooting .25 gr King 0.25s at 45 fpe. The flight spin rate was then 1:64 inches for the .22 at whatever the velocity. ... Kind regards, Harry.

Harry, on one of the .25 builds I was working on, I tried some other more conventional bullet shaped ammo. I have one action that I can adjust up to just about 100ft/lbs in .25.

I tried some "surfire" slugs made by Jerry Boyenga. They are cylindrical slugs with gas rings around the cicumfrence, flat bases, and a short cone for a nose. They come in 66gr, 77gr, and 81gr lengths. On that one particular .25 I found that the ST barrel actually shot them quite well in the 60 to 80ft/lb range, but ran out of ammo before doing more testing at other velocities. I found at 50 yards that the surfires (in this power range) were producing groups as good, if not a tad better than Kodiaks shot from the same barrel(at 45-50ft/lbs), not qute as good as Kings(at 45ft/lbs).

On a conventionally rifled barrel, I have had good success with the surfires as long as I used a LONG barrel, and high power as it seems to take a good bit to stabalize the projectiles. I felt the ST barrel (which was cut to 20", some 4" shorter than the regular barrel I tried) did a good job handeling this ammo, and I will try them again in the future with some more significant testing.



Regards,
DaveG
See more picts @http://davegcustomstocks.com

nt

Comments made here


http://www.network54.com/Forum/79537/message/1333729842/Just+a+quick+assessment+on+how+much+skidding+is+going+on

I have pressed many pellets through ST pipes,and recovered MANY fired pellets at various velocities, and they do show a significant amount of barrel interaction, but not a significant amount of what I would call wiping or smearing of the lead.

The marks left on a pellet seem to be very consistent from projectile to projectile as well.

Regards,
DaveG
See more picts @http://davegcustomstocks.com

I suppose the question is, If the rifle and projectile twist and spin rate differ by so much, how could the pell NOT suffer in the difference?

I'm puzzled

Cheers

I used a sharpie to color pellets before both pushing through, and firing. Even without the sharpie, it is very easy to see what gets done to the pellets on the way through the bore.

top row -



..." If the rifle and projectile twist and spin rate differ by so much..." I think this is where you are getting confused. None of us that aren't work for FX, or have the numbers, actually have ANY real idea what the "spin" rate is of the ST groove set at the end of the bore. We speculate at what it might be, and Harry has done some testing that indicate that fired pellets spin in the range of 1:70 to 1:80. I think DanB had it at even greater. Out of a Smooth Twist, the spin will most likely change with velocity.

Harry did also state that on most AG's, the nominal spin rate of a grooved bore tends to be in the range of 1:16, but this ratio has nothing to do at all with a smooth twist bore.

Regards,
DaveG
See more picts @http://davegcustomstocks.com

Quote from the thread topic post:
"The first implication of this is that the test pellets shot through the ST barrel of this rifle do not have initial spin rates that correspond to the barrel's nominal left hand twist rate of 1:16". Their actual initial flight spin rate is approximately four and a half to five times slower than that of the actual rifling twist rate."

But with Harry's excellent photos of the back lit muzzle, perhaps the twist rate could be determined.

Question, just how long is the twisted portion of the ST configuration?

TIA

missed that in Harry's post. I have not tried myself to determine the actual twist rate imparted on the pellet as it passes into the ST portion of the bore, but may now.

I will speculate that it will be rather hard to determine though. I have a feeling that the rate at which the pellet spins coming out of the ST depends on the speed in which it enters.

Harry is very good at catching and documenting. I have looked in the end of the ST barrels dozens of times, and it is super easy to miss those lands and grooves he was able to capture in a digital image. They are so faint that they are difficult to measure.



you can just make out the ST impression on this barrel end. It starts on the breech side as just a point,and then a slight stright section, and then starts to hook off to the side. About half way towards the bore end, there is another point inside the groove itself that doubles the depth of the remaining part of the groove. There are 5 of them around the bore.

Regards,
DaveG
See more pictshttp://davegcustomstocks.com

velocity/ mass/ swept area. Which boils down to momentum to swept area to friction per unit time;
or impulse as in ma x t or mv-mu;
or perhaps (mv - mu)/t.
In other words the time rate of change of momentum as the pellet passes through the ST rifling.
There is also the resistance of lead to distortion tucked in there and of course different pellets have different alloys ........ Harry.

[IMG][/IMG]

The section indented is approx 40 mm, 1.575". each groove twists approx 1/10th of the circumference. That gives a rough estimate of 15.75 inches per turn. As I have written, Fredrik told me 1:16" (one turn per 16 inches) and he of course knows. ... KR, H.

presuming that is reflected as the lead-in so to say.. Kr, H.

as the nominal rate of the rifling:
The rifling is very plain to see in these photos which I took: It is the rate of this ST "rifling" I refer to as what Fredrik indicated as 1:16". It looks to be about that.





[IMG][/IMG]

As I wrote in the post the difference between a shot .25 pellet and one pushed through tells the story.
This is .25 cal:

Shot:



Pushed: Showing the section mated to the "groove". This gets stripped off when a pellet is shot as the pellet does not follow the lands and grooves when rapidly passing through at only 1/5th the barrel rifling twist rate.



I have been unable to get a .22 pellet to bite into the rifling sufficiently to not strip and so show the reflection of the barrel grooves. This is why all the pellets shot or pushed look similar.

Dan's work which I asked him to do is collated here for others now: But the barrels have evolved a bit since then. My .22 is showing as 1:44" to 1:90" effective spin depending upon pellet or bullet used and weight and velocity. But is consistent for each particular pellet.

http://www.network54.com/Forum/79537/message/1333694153/Yes+%2C+you+may+recall+I+asked+Dan+to+do+the+test+and+outlined

I will hopefully have some movie for you as I indicated when we get back Dave, to show what may be possible for me close to the barrel .......... Best regards, Harry.

hehehe, I was out trying to get a pict while you were posting the same thing. Go figure.

Regards,
DaveG
See more picts @http://davegcustomstocks.com

These are some of the surfires and a 50 yard target I shot from one of the .25 ST barrels I originally had here to test. I didn't write it down, but I want to say the gun was shooting at @70-75ft/lbs or so that day.

The center dot is .25" OD surrounded by a .25" black ring for a total of .5" inside a 1" circle.

Regards,
DaveG
See more picts @http://davegcustomstocks.com

CTC 0.52 inches ... That is excellent for grouping cast bullets Dave.

[IMG][/IMG]

Thanks for that. The ST barrels are an interesting bag of fish. You know, most think Ben Taylor dreamed this up. It was actually Fredrik that began re-visiting the 130 year old Paradox system and experimenting with rifling the last part of the barrel, as I understand it. What Ben did was to come up with the variation of a machine for choking barrels but pressing the rifling in from the outside. A combined effort. Fredrik has done a LOT of experimenting since then to get to the present position. ... He is now working as hard as ever. It just MAY get a little better now. We will have to wait to see. ... Best, Harry.

I hope you don't mind if I use this picture to explain what a well built gun and ST barrel can do!

Some day I might get a few of your bullets in about 40 gr weight myself .... But freight to Australia is the killer...... Kind regards, Harry.

already answered but, since the rifling is only 1.5" long and it's consistent with that of 1-16" twist, since the pellet doesn't make a full revolution while in the barrel, the pellet once out of the barrel no longer SPINS 1-16" twist correct but slower? Hence your numbers of 1-40 through 1-70" correct?

Would faster or slower than 880 FPS change your accuracy dramatically?

The pellet never gets to spin at 1:16" in the barrel, as it never can correspond to that rate. It reaches its effective spin rate in the process of stripping through the rifling. That is then the rate it has leaving the barrel and according to the rate change of momentum going through the rifling. That can vary with pellet velocity, mass and I think swept area of the pellet. See my related response here somewhere.

Then - the full implications of your question is not so simple to answer. Superficially I have so far found the .25 barrel to shoot well from less than 880 fps to 930 fps with Kings, though I favour around 880 fps. Polymags don't mind full blast at 930 fps. Baracudas will only reach 860 to 870 from my rifle and shoot very well. Benjamins reach around 895 and shoot well. The only ones I have shot to beyond 100 yards yet are the Kings - see the 183 yd target.

I still have much to do and I set priorities for the time I have, mostly when at the farm, but I will see what happens at lower velocities. I can get down to about 750 fps or so with Kings but some other variables than the ST rifling enter the picture. My rifle was set up to shoot with valve/ striker etc., balance at 44 to 50 fpe depending upon pellet weight etc., so, like all rifles, I guess that is where I should expect the best results. 90 shots at that power with a less than 20 fps (16 or so) extreme spread from 500 cc in a mechanical rifle is a standard that I am not really prepared to risk messing up. I doubt there is anything else out there that does better.

As time permits I will get to shooting at lower velocities within the striker spring adjustments range that I have available. ............ Best regards, Harry.

but, you answered it just the same. The pellet truly does not make a full revolution while in the barrel.

But anyways, your finding are very well documented and appreciated.

Tofazfou

ST Barrels deify all logic, well that was what I thought over a year ago. But now after owning one all doubts are removed in my mind. FX has a winner, and that is all you can say.

In fact we may only be on the first rung ... well not THE first rung as my barrel made a year ago was one of the 16th iteration of ST barrels. Work is still going on; but you are correct in that the present status is excellent - achieved with enormous effort from Fredrik who is not done yet. I have only just become acquainted with him and he is one driven engineer but one still keen to listen, learn and go forward.......... Kind regards, Harry.

All I know is everything I aim my FX 500 at it hits. What a great report! Way more than I could ever imagine. Now I have to try and absorb all that info. Thanks, Scott

I have done a lot now and have more to do. When I got my rifle, after a journey of about nine months in all, I wrote that there would be reports but it may take time. This one is a sort of summary, the outcomes of which only time and industry will reveal. ...

At any rate I like the rifle, it is very accurate, with the best few pellet types, and the aesthetics of a bottle gun are not so bad when one gets familiar with them. I'll feel even more comfortable when my left handed stock gets here (before Xmas I hope). They were not available when mine left Sweden way back then. .... Enjoy your rifle, Kind regards, Harry.

I would like to take the oportunity to say " Thanks" to Harry for taking the time and shared his valuable informations. I am pretty sure many of us will enjoy and appreciate the hard work you put into you report.

Thanks,

JP

nt

You have been very busy . I don't think I have shot my Rapid in 2 months. That will change soon.

daisy

And if I don't see you tomorrow--HELLO

on the dresser for me. At our age wasn't that nice! I just may take your advice and go share it with her!!

The report took some time to collate and I hope I don't have too many typos to deal with - but let me know if you spot any ....

Happy Easter to you and Lois, David ... Harry.

and it's rifling/smoothbore, I've oft thought about how much or how fast that pellet spins compared to a conventional rifled barrel. Your post was as usual very informative and leaves quite a lot to absorb in. What you say makes sense.

I think the ST barrels are MAGIC......lol

While i don't respond to each and every one of your post.........i read them all. So keep up the great work and your analysis and ideas are much appreciated.

Tofazfou

At first, I thought it was a missprint, and asked him to confirm, which he did. I soon had opportunity to test a different rifle of the same type, and noted very similar results ... fairly accurate, and with very slow rate of spin (between five and six feet per rev). These two rifles were in .22.


I discussed these observations in person with Frederic, and he was accusing me of "putting him on", steadfastly refusing to accept it.

These observations confirm my longstanding belief that A. twist rate for typical air guns is not that critical, so long as its not too fast. B. Twist rates are generally a bit too fast for longer ranges, mostly due to the tendency to apply longstanding firearms lore to airgun production.

BTW, the observed spin rate for these barrels will change markedly with pellet type and the power output of the gun. Thankfully, they still seem to shoot ok despite.

Just shows there's often little need to obsess over things.

an old method for the study. He had just acquired this FX Independence and obliged. Again I thank Dan for that.

Any who are interested in this research can follow the chronological paper trail below and the interesting initial results:

June 18 2010 11:07 pm
http://www.network54.com/Forum/79537/message/1276916849/ST+FX+barrels+..........+Owners%2C+here+are++the+tests+I+would+like+to+see+done+..........

June 19 2010 6:59 pm
http://www.network54.com/Forum/79537/message/1276988390/Smooth+twist+or+no+twist+at+all

June 19 2010 7:33 pm
http://www.network54.com/Forum/79537/message/1276990396/Thank+you+Dan+--++Looks+like+a+1-240%26quot%3B+spin+rate++or+virtually+zero-

June 20 2010 7:20 pm. Dan confirms the concept and a left hand twist (same direction as my barrels).
http://www.network54.com/Forum/79537/message/1277076002/Smooth+twist+rate+confirmed

Presently the barrels I have are left hand twist. They are not as shown in the pic in one of the above posts. Dan's was a left twist barrel (Edit).

Fredrik understands perfectly the results, concepts and implications of my tests. He contacted me after I sent him some reports on my initiative (a month ago). He did not at first, but then did his own tests and reported his results back to me. We are now exploring the inferences and he is undertaking developments that will lead to further understandings we hope. The objective is to marry the twist rates to the spin rates. Results may be made known in due course.

.... Kind regards, Harry.

of the testing you and Fredrik are doing.

I really admire the type of work and detail you put into evaluating everything you set your mind to.

I have some theories about what is happening with the pellets when they leave the ST bore, but without actually being able to see them, it is difficult to know for sure. In the end, what is important is that they hit the target, and out of the batch I currently have I am getting some very nice constant results. I have been quite pleased by the fact that the average size of group I can repeatably produce has been almost identical between a fair number of test barrels that I have been shooting.

I have more work to undertake to get everything RIGHT where I want it, but I am confident enough with the results the bores are producing to feel that I am headed in the right direction.

Regards,
DaveG
See more picts @http://davegcustomstocks.com

anything in pellet flight after the pellet comes into view of the scope cam at a few yards, then feel free to have me email you for instructions. ... There's still stuff I've done but not shown. .......... We are headed for the farm Sunday for a week. It is Friday night 10:07 here now. .......... Best regards for Easter, Harry.

OK, I have been putting shrouds on guns for more than a decade. I mean, I've done hundreds of them.

There has been a pretty decent amount of evolution in shroud building since the beginning. The major improvements coming in the form of air stripping right of the bore exit. I have found that the ST barrels are particularly sensitive in this area. I have played enough that much of the effect I am getting can in no means be caused by clipping, yet I know something is happening here.

The effect is profound enough that I have gone to building just an air stripper (adjustable of course) so that I can test some of my theory without being hindered by the shroud obscuring the stripper. I have been able to acheive measurable results on a target.

I find that in comparison to a conventionally rifled bore, I need more clearance around the actual muzzle end to avoid influencing a pellet. Much more than one would think. My mind brings me to an arrow leaving an archers bow. The arrow may precisely strike a target, but it sure does look funky coming off the string.

I think what I would really like to study is a side view of the pellet exiting the bore. My fear at this point is that it would need to be at a much higher resolution and slow-mo than is possible with us tinkering with small digital cameras in a home setting.

Regards,
DaveG
See more picts @http://davegcustomstocks.com

(frames per sec) is a streak line. But I will fiddle while at the farm to see what I can get through the scope from behind as it shows much about yaw and gyration. I shoot with a bare barrel but I will try the stripper I had made. I really don't have much faith in the stripping action but do think the cone adjustments may make a difference as a weight tuning device for some rifles and barrels. All mine seem to perform up to snuff as bare barrels. Noise is of no consequence to me and suppression is not an option. Thus I have no negative influences from any extra bits.

I do understand the demand up there though ..... I'll see what I can come back with from the farm in a week or so.
Best from harry.

technology because of the supposed improvement over conventional rifling. I shoot my 500 Royale at 920 fps and like the accuracy. I still will turn it down to test at lower speeds, but I bought this gun to be a 50 fpe shooter.

Winds light and variable!

You could try Baracudas and Benjamin domes too. they will lift your fpe whilst lowering your fps.
Mine will do 50 fpe with those pellets. But after all is said and done, everyone knows that sufficient accuracy is the most important thing. Chasing fpe for its own sake is really not an end in itself. Try Polymags for fpe delivery and possibly excellent accuracy; and Baracudas for penetration. Kings may still be the most accurate in .25 and they fall in between for fpe delivery and penetration. The Benjamin domes are pretty good too ... Kind regards, Harry.

Winds light and variable!

And as usual we received a golden quality report we ve come to expect from you. I put it up as POM, excellent and thank you.

Steve
Yellow Forums Owner
http://www.yellowforum.com

nt

Nt

Steve
Yellow Forums Owner
http://www.yellowforum.com

...the articulate manner in which you share such good information with us. Fascinating research! I think I understand what you are reporting here, although I may go and re-read once or twice more! LOL!

I have a few questions regarding a couple of your comments in the threads further down the page. We agree the Elite is a "relatively" light rifle with a light barrel shooting high power. Your comment: "I might add that the thump of the pellet to the ST rifling takes place at the very last instant before the pellet is in free flight" was very helpful. I had not thought of that and it explains a lot about the feel of the shot cycle of the Elite. I'm sure this image in my mind will reinforce the importance of follow-through and help me to focus and improve my shooting with this rifle. THANKS! I wonder: do you feel a great difference in the shot cycle of your .25 BSA compared to the elite? Does the BSA have a heavier barrel (would you happen to know the length of the BSA barrel off-hand?)? Does the ~44fpe cause both rifles to jump similarly? Do both rifles require the same amount of shooter skill and attention to attain precision? I'm finding that my .20 rifles at 25 or 26fpe are considerably easier to shoot -the firing cycle is very calm and forgiving compared to the .25. I'm curious if any airgun producing 44fps will simply be more difficult, or if this can be mitigated by adding additional weight to the rifle or perhaps something else?

Also, is your .22 ST barrel the same length as your .25? I would love to know the power and velocity your .22 barrel is producing when installed on your Elite w/out changing any of the settings from your 44fpe in .25. I happen to have those results for rapid barrels in .177, .20 and .22 if anyone is interested.

And thanks again for the barrel swapping tutorial! Your comment: "A final check is made to feel that when the action is opened and closed the lever has a tiny "over centre" feel as it closes; just a tad not a crunching lock-up." is exactly what I needed! MOST helpful! I've made some re-adjustments after taking your advice and my rifle is much better now. One last thing: my cocking lever seems to have loosened up a bit now that I have a few hundred pellets through the gun. Its got a bit of vertical slop or wobble that it didn't seem to have at first. Do you know if there is an adjustment for this?

THANKS again!

Scott in CO (proud owner of Elite # 008!)

When you swap Airgun barrels on that gun or when you remove and replace the barrel, before tightening the set screws all the way, make sure the barrel protrudes out the bridge just enough to have a tight seal when you close the bolt handle.
Hard to explain, it's a minute and you know it by the feel. Then just tighten the screws all the way.

Steve
Yellow Forums Owner
http://www.yellowforum.com

nt

Q. I wonder: do you feel a great difference in the shot cycle of your .25 BSA compared to the elite?

Some difference but not what I would describe as great. The BSA all up is a pound or so heavier and the stocks are very different. There are subtle differences that I haven't committed to analysis.

Q. Does the BSA have a heavier barrel (would you happen to know the length of the BSA barrel off-hand?)?

The BSA barrel is 15.3 mm / 23.5 inches; the Elite a tad over 14 mm call it 14.1 mm / 23.75 inches.. However the effective length of the ST barrel is say one inch longer due to no internal chamber/ transfer port etc.

Q. Does the ~44fpe cause both rifles to jump similarly? Do both rifles require the same amount of shooter skill and attention to attain precision?

I shoot with the same attention to all important facets with every rifle; but I think there is an undefined difference in the reactions of the two. I'll be at the farm for a week from tomorrow and will pay more attention, but will be spending most available time shooting the 28 fpe BSA Hornet but at 19 fpe.

Q. I'm finding that my .20 rifles at 25 or 26fpe are considerably easier to shoot -the firing cycle is very calm and forgiving compared to the .25. I'm curious if any airgun producing 44fps will simply be more difficult, or if this can be mitigated by adding additional weight to the rifle or perhaps something else?

28 fpe is calmer than 44 fpe. I think I was the first to shoot sub 0.75 inch at 100 yards with the .25 cal (reported here) and there were plenty of Rapids about. I recall many excuses / reports previously to the effect that .25s were inherently less accurate; that more than 35 fpe was too difficult etc. Of course Kings changed things somewhat, but care with shooting is always at the ground floor isn't it?

Q. Also, is your .22 ST barrel the same length as your .25? I would love to know the power and velocity your .22 barrel is producing when installed on your Elite w/out changing any of the settings from your 44fpe in .25.

The .22 barrel is 19 inches/ a little under 50 cm so much shorter. Full rifle is 37 inches bare, no muzzle weight things. I'll try to do a test for .22 power v's .25 power on the same setting this trip Scott. I have not shot the .22 barrel much to date as I have not really got to researching it yet. It is a tack driver at 25 metres and that 50 metre target showed potential.

Q. One last thing: my cocking lever seems to have loosened up a bit now that I have a few hundred pellets through the gun. Its got a bit of vertical slop or wobble that it didn't seem to have at first. Do you know if there is an adjustment for this?

There is a little fine pivot screw that goes down through the receiver and on which the lever pivots. Mine was actually not screwed right home and the lever became loose. You need a tiny screw driver, I think it was a slotted type not Phillips. I screwed it down and no problems. I have had the action apart once and that screw has to be removed to get the lever etc out. Check that screw/ pivot rod.

I think that covers all your questions. I'm glad the tute on barrel R&R was helpful. ..... Best regards Scott until I return about Tuesday week .... Lots of enjoyable physical work to do up at the farm. First will be mowing, then getting the chainsaw and axe out for winter wood.etc. ..... Harry.

Wow, I didn't realize how quickly so many questions had piled up! Sorry to hit you with such a large load, and thanks for addressing each one! Thnaks again for sharing so much good info. I especially appreciate the help tightening my cocking lever.

Have a great Easter!

-Scott in CO

to be very interesting and educational.

nt

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nt