When shooting a heavy springer like a TX200 or LGUOctober 11 2017 at 9:10 AM
|Don Armstrong (Login doninva1)|
is there a balance point that the fpe can be reduced to a point that you can drop targets at 55 yards and the gun gets less hold sensitive. I think the UK guys shoot somewhere around 10.5 to 11.5 fpe. I know they are limited to 12 fpe. Thanks, Don
if the target is properly set up
|October 11 2017, 11:45 AM |
you can drop it with 10.5 but it might depend on the pellet as well since the BC effects retained energy. So, depending on the target brand and how well set up with a pellet with a good BC like the JSB 7.87 which I use 10.5 should be adequate. I have shot that low with a Pr Sport and I shoot about 11 with my LGU. I can't speak to going lower that 10.5. I understand that the Worlds one year were won with a gun shooting 10.5.
|October 11 2017, 1:06 PM |
I shoot in the 780-790 fps range
|October 11 2017, 8:22 PM |
I normally try to keep my TX200 at or about 790 fps with Air Arms 8.44 grain pellets. That seems to be a sweet spot for power vs smooth shot cycle. I shot the entire match at Baton Rouge at 775-780 fps (11.3-11.4 ft lbs) and did fine at that power level.
It depends on how you shoot and the Division you're shooting in
|October 12 2017, 5:05 AM |
If you shoot Open, or WFTF, then keeping the most accurate pellet for the barrel at around 800 fps is a good idea.
If you are shooting Hunter going to the 13 to 15 ft-lb range may give you better overall results.
A little flatter trajectory, a little less wind drift when the ranges get stretched and 12X (or 16 after November) is not enough to compete with guys using $3000 scopes, may be better for you.
Pellets themselves are stable up to about 875 fps for the most part.
And targets MUST fall when hit with 4 ft-lb.
So, it's not terminal ballistics what you should be worried about.
Some FT rifles weigh upwards of 16 lbs, and that also makes a difference.
In general shooters do better when they get used to shoot a rifle that weighs at least a lb per ft-lb of output.
So, you can also choose to up your game, get a custom stock and get used to a heavy rig.
Yes it is a balancing act, but there are many more variables than MV and ME.
|Louis Bigelow |
|October 16 2017, 8:17 PM |
My lgu shoots 780 with aa 10.34. shoots reasonably flat. and hits at 55 yards hard enough to drop it every time -I- do my job. practice means more on a springer. and I feel I get better wind penetration. (heavier pellet moving faster downrange.)
|October 12 2017, 5:27 PM |
Talk to Ray Apelles, Matt Brackett, & Steve English. See what they say. Focus on what's consistent, bypass what's not.
My springer shooting days are fast fading into memory, but I'd guess that hold consistency and trigger control are far more important than FPS.
At this year's worlds........
|October 12 2017, 9:47 PM |
I shot 781 ft per second on check in day. That was right where my gun was supposed to be shooting. On the first day of competition it was very damp and raining. During the match Crona graphing I came very close to being disqualified. It shot 801.49 feet per second with air arms 8.44 grain pellets. All spring Gunners were shooting hot that day. A couple even got disqualified because of it. Normally I try to have my gun shoot 15 feet per second below the 12 foot pound limit. But I am now considering lowering my gun to 770 ft per second to make sure that I don't get disqualified in the future. I know of too many shooters that are trying to get very close to the 12 foot pound limit to try to get an advantage. But that Advantage would be null and void if you're disqualified at a major competition like the world's. So in the future when I'm tuning my guns I will be shooting for 770 feet per second. That amount of cushion seems to be necessary to make sure to not get disqualified. PCP Shooters probably don't have that same problem. The spring gun shooters compressing the different air is what makes the difference. I suspect because the air was so heavily dense with water that it compressed to a higher pressure causing a higher velocity. All of the spring gun shooters were shooting very high on the first day and the second and third day we were right back to where we belonged.
When our senses trick us
|October 13 2017, 10:11 AM |
Attributing a rise in MV to the humidity of the air, while it sounds logical (after all, we ALL know that breathing in damp air is harder), is not physically possible.
Simple reason is that humid air is LESS dense than dry air.
Now, COLD air is MORE dense than warm air and, usually (except for the tropics -of which I am convinced Maryland forms part of-), rainy days are overcast and cooler/colder than sunny days.
You are right that denser air creates higher MV in springers while not affecting PCP's, but there are OTHER reasons why a rainy day CAN cause higher MV's.
One of them, and the most probable one, is simple: Damp pellets.
At the peak pressures and temperatures we operate during the compression cycle, surface dampness in the pellets gets flash-evaporated into steam, and THIS CAN AND WILL increase MV's. Surface dampness in the pellets can come from handling with wet hands/gloves. Handle a pellet with wet hands and see what happens. At least the tests I have done have been conclusive for short transfer port guns (all sliding compression cylinder models), less so with break barrels and long transfer ports.
I have also found that the degree of "wetness" is affected by the lubricant, or lack thereof. Bare lead pellets being more easily "wetted" than lubed ones.
PCP's function on the "cooling" side of the curve. Expanding air always cools everything down and humidity can condensate on the cooler inside of barrels and, in this sense, damp BARRELS create a peculiar and inconsistent set of variations.
Another reason why a chrono that is operating in a rainy day outside (even in a gazebo/tent), is that small droplets CAN be carried by wind and/or condensation be deposited on the lenses of the optical screens of the chrono, and distort the reading by altering the "perceived distance" between the chrono screens.
Yet another reason for a chrono to change its readings is inside temperature, some electronics are sensitive to the temperature they operate in and colder temperatures may slow down the electronic clock that measures the time interval between triggers of the screens; a slower clock means less pulses between triggers, therefore the chrono "thinks" it is a faster projectile.
Yet another reason for a chrono to change readings is the ORIENTATION of the chrono to the natural light source. This is avoided in self lit chronos, but not all chronos are self lit and those that are, are also very compact units with very short distance between screens, so a small difference in how the clock runs creates a larger difference in the final reading.
Lastly, and possibly more importantly, there is the fact that you used one chrono at the sight-in range, another on the first day of the match, another on the second day of the match and another on the third day of the match, as each course requires a chrono. And, remember that all springers shot together the whole of the courses (unlike Lisbon), so one "fast" chrono used in the course that was assigned to springers' first day could have also contributed to the perception.
Chronograph manufacturers know that the difference between one chrono and another can be up to 5%, nowadays we rarely see such a difference except on "bargain basement" models (mostly the folding type), more serious manufacturers can guarantee a calibration of around 0.5% and even 0.05% at issue of the device, but only for a year. After the first year chronos should go back for recalibration, if you are going to be serious about the reality of MV's.
Now, some of these conditions can even happen all at the same time in a rainy day and would explain easily the 2.5% difference between one chrono reading and the one taken the next day under different environmental conditions.
I do agree with you that we each must decide what chances we take, and I also recognize that Wales had a specific legal restriction to enforce that is ONLY valid in some countries, though here I have to say that it is good that no "Peeler"(Policeman) was sent to enforce the law at the shoot because by all calculations, you WERE shooting at an ilegal MV, LOL!.
The Poles have already declared that the ONLY restriction airguns have in Poland is being under 12½ ft-lbs. So it is quite possible they will implement a table of tolerances as used in Italy, Germany, Lithuania, New Zealand, and Portugal. Though the Annexure A of the WFTF Comprehensive Rules already has a SMALL tolerance implemented there (0.05 ft-lb).
Until WFTF starts to become more scientific and serious about the standards, there will be differences caused by the location of each year WFTC's.
But WFTF seems to be afraid of science, technology, and progress; so it is what it is.
|October 13 2017, 3:48 PM |
|October 12 2017, 7:23 PM |
I shot quite a few, maybe ten matches at 9.3 - 9.5 FPE using JSB 7.87 gr pellets. I don't remember any targets not dropping (the ones I hit).
It all depends!
|October 13 2017, 9:14 AM |
As others have said, you have to figure out what works for you. Don't be afraid to go low on power, but the most important thing is a consistent hold.
A consistent hold often comes from a rig that's setup to fit you (good ergonomics)
1lb of rifle per 1ftlb is the general rule of thumb.
Shooting a springer is more about the journey, and enjoying that frustratingly pleasant journey - cuz at any time your perfectly setup rig can take a nose dive for no (easily identifiable) reason, and if you can't come to accept this possibility, it's not a fun experience!