Wow I think you have it going your wayYour long range experience is a big plus You know the longest shot with a 257 is 600 yards on a Pepsi can.Charlie did it a couple years ago. He was an experienced long range shooter also.
Thats some very INSPIRATIONAL shooting Carl and i love that gun of yours. Its so Bench Rest.......I need to film another long range session here soon now that it APPEARS some of the 20+ mph Cali winds might be gone. But the heat is for sure hear. So out with the wind and in with the Mirage.But like you said, its cool hitting clays and soda cans at that range but, when the wind kicks up just a little, your no where near your last shot with the calm wind........lol! When i did my 446 yard hit, i practiced many shots before i filmed on just the rock face simply because i had never shoot an airgun that far. So in the video, i hit the can in only a few shots because i practiced before hand. And while it was a little easier to hit the can, it was still hard.500 yards will be my goal coming up here soon.But anyways, back to you, so glad to see another long range SUCCESSFUL airgun shooter. People have no friggen idea how hard it is to hit a little clay at 580 yards...........GOOD LAWD!
Man it makes me want to sell my backup vehicle...
WOW! I'm thinking for a 257 build and going the same route of ordering a frame and going from there..
Something you should be aware of, is that the wind drift will actually increase as you push beyond 1000 fps with any projectile.... If you play around with the JBM Trajectory calculator, and pick any bullet you want, you can see what happens.... As an example, here is what happens at 100 and 400 yards for the Eley Tenex .22LR 40 gr. (BC 0.140, G1) solid at various velocities....700 fps - 4.5" - 78"800 fps - 4.1" - 69"850 fps - 3.9" - 66" (minimum drift at 100 yards @ 880 fps)900 fps - 3.9" - 64"950 fps - 4.0" - 63.7" (minimum drift at 400 yards @ 950 fps)1000 fps - 4.2" - 64"1100 fps - 4.8" - 68"1200 fps - 5.5" - 72"1300 fps - 5.9" - 76"1400 fps - 6.0" - 79" 1500 fps - 5.9" - 81" (still supersonic at 100 yards)1600 fps - 5.7" - 83"1800 fps - 5.0" - 83"2000 fps - 4.4" - 81"2400 fps - 3.3" - 74"2800 fps - 2.7" - 64" (requires this velocity at 400 yards to have the same drift as at 950 fps)You can do the same thing with any bullet you choose.... I certainly shows how pointless it is to push over 1000 fps, even more so over Mach 1, with an airgun....Bob
Transonic does NOT mean passing through Mach 1, it refers to speeds between Mach 0.8 (900 fps) and Mach 1.2 (1350 fps).... In this region, the flow is changing from subsonic (below Mach 0.8 ) to supersonic (above Mach 1.2), and the drag increases by a factor of three to five times, and with it the wind drift.... The exact point where the greastest increase in drag occurs is called the Drag Discontinuity Mach Number, and is usually between 800-1000 fps, and above that point the increase in wind drift and decrease in BC is drastic.... Existing Models, such as the G1 model, are not very accurate for pellets, or even for the flat nosed bullets we use, but in every case the drag at 1100 fps and above is many times higher than it is at 800 fps and below, and so is the wind drift.... The drag is so high, however, that a bullet starting supersonic or nearly so falls back subsonic very quickly, and so only experiences that high drag, low BC, and high wind drift for the first short part of it's travel.... Pellets launched at 1200 fps are subsonic in just a few yards.... We need to study the flat nosed bullets we use to find how they perform in the transonic (900-1350 fps) region as they may not be a very good fit with the G1 Model....There is no evidence that a properly stabilized pellet has to lose accuracy and keyhole when fired supersonic, and in fact that is a completely separate matter to drag anyway.... BTW, the speed of sound is almost completely a function of temperature, not atmospheric pressure, altitude or humidity....Bob
A wise man once said that in theory, there is no difference between theory and reality.... but in reality there is.... All I try and do by adding the theory is explain what reality shows to be illogical.... For example, simple logic would dictate that the faster you drive a bullet, the less the wind drift.... Over the years, that has been proven to be true subsonic and supersonic, but not transonic.... For example, .22LR Target ammo (subsonic) is less affected by the wind at 100 yards than the High Velocity (supersonic) variety....If the reality doesn't consistently match the theory, then it's time for a new theory....Bob
Advertise Here
Share This!