The greenies must be seeing red over this
on 01/29/2009 at 06:32 PM
Hmmm I like the idea, but I think this is more marketing hype than outright performance. I have one of these in my collection....
http://www.falcon-airguns.co.uk/pages/rifles.htm
In the UK it’s restricted to 12ft lbs, but it’s fairly easy to increase the power to 16 or so especially with the larger calibres like .22 and .25 Unfortunately the ballistic coefficient of a .177” pellet is pretty pathetic and making it lighter won’t improve matters. There is also the problem of pushing the diabolo shape at supersonic velocities despite what they claim. The shape doesn’t work well at the cross over between super and sub sonic velocities.
Twenty or so years ago a company called Sussex armoury brought out a pellet using a plastic sabot. The idea was great. A .22” mass pellet with a diameter of a .177” but shaped like a proper bullet. Trouble was sabot didn’t open reliably. Some shots were good, but most were hopeless.
I think I will stick to good old lead!
It’s been a while since I did O level Physics but I thought E = 1/2 MV<sup>2</sup>
No, the physics hasn’t changed, just the quality of the typist; the modern version of the & html code for 1/2 doesn’t actually have a t in it. It’s frac12 not fract12. fract12; doesn’t even show up.
So what would the Muzzle Energy of an Optimum 9mm Copper projectile be
if held to no faster than 1040 FPS and thus avoid the Transonic problem?
Probably way outside of the UK Muzzle Energy limit.
Also What would be the Optimum weight to maintain this Velocity?
Are there any Air Guns in 9mm, I thought the .25’s were the largest available..25s? Oh hell no. You can get airguns up to .50 caliber and use them to hunt Cape Buffalo.
I think the transonic issue is more of a bullet design and rifling twist issue, perhaps influenced by muzzle turbulence. In English that means I’ve fired big fat bullets at low velocities out of guns with a fast pitch in the rifling, and they don’t go unstable when they slow down to the subsonic speeds.
Also, the mass has nothing to do with it. Retaining the velocity is all a matter of aerodynamics, which is something no airgun pellet actually has any useful quantity of.
However ... aerodynamic bullets tend to be quite long for their diameter, and thus usually weigh a lot more than “regular” bullets of their caliber. But if you make the bullet out of something lighter, like copper, then you get better aerodynamics PLUS lighter weight, which almost always means higher velocity to begin with. This is why the Barnes bullet company is doing such a booming business (no gun pun intended) selling their Triple-Shok copper bullets. For the big calibers, they are the only way you can get anything even close to aerodynamic without having to get a custom barrel*.
* because extra long bullets require faster twists to stabilize them properly. The Barnes bullets don’t, because they aren’t really any longer than regular bullets of higher weight. It’s a complicated balance thing that involves lots of math. Google up “Greenhill formula”.
Didn’t Lewis & clark carry an air rifle with them on their expedition?
interesting post. any permits required? does the quite version slow down the muzzle velocity? how about getting gunned down by cops that don’t know them by sight?
whats the absolute furthest range safety-wise? ®And I’ll agree with the 45-70 preference for boar.
Thanks Guys, Have ordered some Barnes Triple Shock in both 250 and 300 Gr.
for a .458 Socom Upper. They said it would be 12 to 14 weeks.
Have the Brass and Projectiles But so far the Dies have not been shipped.
Never hunted Boar, But maybe will hunt Bores in the Future.
01/29/2009 at 07:37 PM
