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Lunch time check in... Some picts

August 10 2011 at 12:35 PM
DaveG  (Login DaveG)
YF

I'm busy getting a few things wrapped up over the next day or so, so play time is very limited with the ST barrles. I did get a confirmation call that more barrels are indeed on the way. I also got a really interesting tip on enhancing the accuracy from the ST barrel by using some non-lead pellets in conjunction with regular lead pellets. I'll report on that one as I have time to test it for myself.

The 1st test bed-
[linked image]

One of my own Raven actions with a Smooth Twist barrel installed for testing.

Some targets -
[linked image]
[linked image]
[linked image]

5 shot groups just short of 50 yards shot off a front sand bag rest on the table of my bandsaw in the shop. I was standing. JSB 15.9 as 875fps. On the first target(top), I pulled the first shot just as I was getting ready, so aimed at that hole for the rest of the 5 shots. Bottom target, that one on the right was ALL me for sure.

I'll be the very first to plainly state that I am terrible at shooting paper. Couple that with the two cups of espresso I had to start the day, and draw your own conclusions.

Regards,
DaveG
304-273-0937 after 6pm EST
See more picts @http://davegcustomstocks.com

 
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boo
(Login boohoo9)
AR&P

Re: Lunch time check in... Some picts

August 10 2011, 1:35 PM 

Do you think the idea behind using non lead pellets is to slick the bore?.
Sorta like a mild bore lap?.

boo

 
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DaveG
(Login DaveG)
YF

dunno'

August 10 2011, 5:12 PM 

pure speculation on my part, but it is one of two things... Either they are leaving a deposit in the bore that works well with the lead mix of the JSB's, or they are coated with some sort of release agent from the manufacturing process that lubes the bore?

Either way, they are a non-lead pellet made in the UK? I will follow up on it as sooon as I can, and do a complete test while I am at it. Let you know what I think then.

Regards,
DaveG
304-273-0937 after 6pm EST
See more picts @http://davegcustomstocks.com

 
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John Lucas
(Login jlucas50)
AR&P

Oh yeah, Dave...that's just terrible shooting. LOL. nt

August 10 2011, 2:33 PM 



"Silence is the only thing that can hinder the Truth"

 
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DaveG
(Login DaveG)
YF

gun/barrel combo

August 10 2011, 5:14 PM 

Made me look good didn't it? Now you know why I say that so far with what I am seeing out of this first test subject, I am happy.

Regards,
DaveG
304-273-0937 after 6pm EST
See more picts @http://davegcustomstocks.com

 
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DaveG
(Login DaveG)
YF

a little more unscientific stuff -

August 10 2011, 5:30 PM 

yesterday, someone had speculated that looking at some pict they found someplace on the internet, that the ST barrel deformed the pellets more than a conventional twist bore, and that the ST shaved more lead off.

Got me thinking, so I pressed 10 H&N Baracudas through the bore of a trusted .25 LW, and a .25 smooth twist.

[linked image]

I did this with the tip of the barrel over a piece of white paper with a circle drawn (the bottom a JSB tin) on it.
Barcudas through the LW-
[linked image]

Baracudas through the ST-
[linked image]

A little hard to see in the picts, but there are some small specs of lead on the ST paper, just not nearly as much as the LW barrel. The smudges on both are where the head of the pellet "drew" on the paper as it popped out of the bore. As previously stated, just by human impression, it feels like it takes more force to push the pellet out of the LW bore choke vs. the ST choke.

What this means is still undetermined, as the LW barrel is a proven tack driver that I depend on. Just thought it was interesting...

Regards,
DaveG
304-273-0937 after 6pm EST
See more picts @http://davegcustomstocks.com

 
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DaveG
(Login DaveG)
YF

additional note to Robert-

August 10 2011, 5:43 PM 

I will try for the "up skirt" picts, but will warn my camera stinks at macro.

What I can describe is pretty much what your own picts showed. The skirts of the conventional bore look just like the ones you show in the first pict, with little tails of lead actually protruding back from the skirt. The ones from the smooth twist show more of a ... well, I would describe it as a very faint curl off the back edge that at least visually seems pretty consistant around the skirt... and obviously rolls in toward the center. Even from pellets I shot out of the .22 ST and recovered. Just as a guess based on visual inspection, I would say that the total area of distortion on the skirt caused by the barrel is @ half on the smooth twist as it is in the conventional bore.

If you look carefully at the line up of pellets I posted here, you can see that there is just a very small ring at the very base of the skirt showing contact with the bore on the top pellet row.

Interesting side note. On the pellets I fired from the .22 and recovered, you can clearly see how the pellet skirt bellowed out to seal the bore.

Regards,
DaveG
304-273-0937 after 6pm EST
See more picts @http://davegcustomstocks.com

 
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robert
(Login gubb33ps)
YF

We are so aware....

August 10 2011, 7:33 PM 

..of how nicely a pllet skirt fits a bore.

Then we kick it in the rump with 3,000psi.

[IMG][linked image][/IMG]

[IMG][linked image][/IMG]

Are so careful about how evenly the pellet is released from the muzzle by a perfect crown...but when the pellet arrives it sometimes has a saw-toothed trailing edge.

[IMG][linked image][/IMG]

(this one has the double whammy of "fins" on both the head and the skirt)

[IMG][linked image][/IMG]

 

So many things we do not really know about pellet accuracy (other than its good or bad), I can't help beliveing that delivering a pellet to the muzzle with a more even base is not going to help.

 


 
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DaveG
(Login DaveG)
YF

I hear ya...

August 10 2011, 8:14 PM 

If, and only IF, I was gonna base an opinion off of just looking at pellets pressed through the bore, I would guess the ST were more accurate. In this case, I haven't yet shot this ST barrel, but I do already know that the mangled looking Baracudas leave the LW barrel and find their mark with surprising accuracy. I already know this LW barrel is a keeper, which is why I chose it to compare against.

I got some more going on with the .22 barrel, and am working along side it with an HW that I have been shooting for a couple of years... As always, more to come.

Regards,
DaveG
304-273-0937 after 6pm EST
See more picts @http://davegcustomstocks.com

 
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Glover, Walter
(Login Voltar1)
AR&P

How is a rolled over skirt in the ST different from symetrical rifling marks

August 10 2011, 9:28 PM 

I would not call the marks and smears left by the rifling lands on the skirt of a pellet 'mangled'
Symetrical marks on a pellet skirt should not detract from its accuracy.

Once you have some recovered pellets from the cotton batting catcher...... happy.gif

It would be interesting to see how ld would make out with shooting this barrel on a USFT or ldSS in his tunnel.
Be easy to prep a sleeve to fit to one of his rifles.

Keep up the good work Dave
Walter....

 
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DaveG
(Login DaveG)
YF

won't speak for LD

August 10 2011, 9:58 PM 

but I do believe that I read a post he made a few days ago, where he said he has tried an ST barrel, and commented that it was OK. I think he maybe shot an independence?

I'm not trying to indicate that any of the deformation on any of the pellets I showed mean anything about accuracy. Just stating what I see. In relation to each other, the normal grooved barrel shows a more distinct form of deformation than the ST. Where you are seeing symetry, I don't think I am. On some of the samples of pellets from the normally rifled barrel, not all the "tails" are the same length, or even near it. I do however feel that these are proabaly either knocked off exiting the bore, or spun off in flight... In contrast, the rolled over edge of the ST pellets takes up less realestate on the pellet, or of the pellet? Again, I am drawing no conclusions that this even means anything. Just that it is what I see.

As I stated, no matter how I may describe the Baracudas as "looking" when pushed from the LW barrel, I know this particular LW tube spits them wonderfully.

Regards,
DaveG
304-273-0937 after 6pm EST
See more picts @http://davegcustomstocks.com

 
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Glover, Walter
(Login Voltar1)
AR&P

It will be interesting for you to catch some fired pellets

August 10 2011, 10:04 PM 

From a fully prepped bunch of barrels with the best leades and crowns possible.

Dave, is the bore of the ST the same size as the head of the pellet? have you measured them?

 
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DaveG
(Login DaveG)
YF

will do

August 11 2011, 6:19 AM 

I don't have anything precise enough to get a real good measure of the ID of the bore. My caliper reads just about the same on the heads of the Baracudas, and the bore of the ST. What I did do though, was to take a sharpie and color a few of the pellets, and then push them through. I did this all the way up the length JUST until I felt the first hint of hitting the choke.

The result, well, the marker remained around the circumference of the heads, and was wiped clean off on just a thin little hairline around the skirt. Just on human impression, without actually trying to get a real measurement, I inserted just the head of the Baracuda into the bore and tried to feel for a "wiggle" while holding onto the skirt. I really couldn't tell. Knowing how the skirts bellow out, I am sure the contact line around the skirt would about double in a fired barrel, and of course the choke makes contact all the way around the head. Looking at them under a magnafying glass the pattern seems pretty consistant around the head. I've previously described the pattern as more of a series of overlapping tear drop shapes, fat on one side, skinny on the other. I can't readily see any of the shapes that look like they vary in size from one another. I will try looking at this with some actual recovered shots though...

Regards,
DaveG
304-273-0937 after 6pm EST
See more picts @http://davegcustomstocks.com

 
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Glover, Walter
(Login Voltar1)
AR&P

look forward to it

August 11 2011, 12:17 PM 

going to get some cotton and tubing

 
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Ted in Madison
(Login unirdna)

Lovin' it, Dave.

August 11 2011, 12:34 AM 

I'm still following your stuff, and it's still reading like a good book. The lead "dust" results are exactly what I would expect. And this is one of the reasons I think the ST barrels do not foul as often.

Very good results at 50 yards from a guy who hates punching paper.

Keep it up!

ted

 
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Graeme
(Login Tractor841)
YF

Re: Lunch time check in... Some picts

August 11 2011, 1:42 PM 

Sorry for asking .. But the little tip you had was not from a guy called clubshot was it. ?

 
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DaveG
(Login DaveG)
YF

don't mind you asking...

August 11 2011, 4:20 PM 

I honestly don't know if he goes by any nick names or handles, but his name is Fredrik.

Regards,
DaveG
304-273-0937 after 6pm EST
See more picts @http://davegcustomstocks.com

 
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Graeme
(Login Tractor841)
YF

Re: don't mind you asking...

August 12 2011, 3:51 AM 

OH.. OK lol

That answered that one for me, thank you.

Great thread by the way.

 
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