Ok I'm just throwing this out here and it may only apply to to most powerful air gun platforms to utilize. They came out with the 8.6 blackout at shot show . yeah so what's the big deal. It is the quote me 1-3 twist button rifled barrels let me repeat one in every three inches a revolution. The reasoning in doing so is the monster in the closet in the powder burner and air gun community. Subsonic sonic velocity doesn't kill like high velocity hydro static shock that we are used to. You are up against a 1000fps limit more ore less. So increasing the spinning power of the .338 long range high b.c 300 grain bullet increases the wound cavity. They invested a lot of money in research for years to learn this. So maybe it will work with big bore air guns too. I now for a fact my very powerful and accurate Texan .510 does not kill a ground hog well at all. It pokes a large hole through they roll around dramatically and go in the hole. Yes they die but its not for me. So I'm thinking for example take my .510 Texan and buy a custom probably cut rifled real fast twist and try it say a 1-4twist 1-6twist in .510. In Air guns using lead slugs with these fast twists I would say powder coating might be the best options. I think this may be the way of the future time will tell. Check out Elvis ammo on YouTube he runs cast heavy powder coated 300 blackout with great results at both subsonic and at moderate velocity. I think air guns at much lower pressure and cool to cold operating pressures are much more friendly to cast lead slugs than are powder burner ar-15 brothers.
Barrel Twist Rpm's to increase power in subsonic?
- Thread starter RM.510bigbore
- Start date
I think there is a limitation to how much twist softlead can handle. The more speed and twist the harder the alloy. The harder the alloy the harder air pressure. Maybe leadbullets in hard PVC or Teflon sabots could take a sharper twist.
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Across all the literature I've read on the subject, twist rate is regarded as having little to no effect on lethality. There are some edge cases that point to a possible link, namely high velocity centerfire rounds with a thin jacket rupturing due to centrifugal force and then fragmenting on impact. That is a different effect and one not applicable to airguns.
If anything, an overstabilized (very high twist rate) bullet will produce less tissue damage because it penetrates deeper in flesh before substantial yawing occurs...i.e. before it starts tumbling and ripping through a greater cross-section of flesh.
And using too fast a twist rate will negatively affect the accuracy of a projectile. Shot placement is the name of the game so anything that detracts from accuracy is a move in the wrong direction.
A .22 cal pellet at 30fpe to the brain of a groundhog will anchor him where he stands. Meanwhile it may be that a half-inch hole through his lungs won't deprive his brain of oxygen quickly enough to put him down before he makes it back to his burrow.
If anything, an overstabilized (very high twist rate) bullet will produce less tissue damage because it penetrates deeper in flesh before substantial yawing occurs...i.e. before it starts tumbling and ripping through a greater cross-section of flesh.
And using too fast a twist rate will negatively affect the accuracy of a projectile. Shot placement is the name of the game so anything that detracts from accuracy is a move in the wrong direction.
A .22 cal pellet at 30fpe to the brain of a groundhog will anchor him where he stands. Meanwhile it may be that a half-inch hole through his lungs won't deprive his brain of oxygen quickly enough to put him down before he makes it back to his burrow.
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I don't want you take take this the wrong way but if your 50 cal Texan is struggling to put down a groundhog, the problem is you and not the gun. Thats just bad shooting. I use a 17fpe 97K and a 20fpe Marauder for those guys. A 15.89gr pellet to the side of the head right behind the eye will put them down instantly every time.
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I was making the point with the groundhogs that 800 foot pounds through the lungs with a .510 hole does not kill like a 22 mag would taking the same shot. Now different situations I think you could shoot a buffalo or moose through the rib cage and have full penetration and decent results with the same .510 800 foot pound slug. I think the 300 blackout shooting subsonic 30 cal 200 plus grain bullets in 30cal had problems with reliable killing power. Check out some of the ballistic gel test on the 8.6 blackout.. The video shows more initial energy jump into the gel with the faster twist. They invested a lot of money into this 8.6 and the results are iteresting. Elvis ammo on you tube is shooting fast twist 300 blackouts with powder coated slugs with no gas checks with great results. My point being if the can shoot in a powder burner with heat and multiple times the pressure in a 7 or 8 twists full auto. I would say that are3600 to 4500psi cold air guns are much easier on projectiles. I'm not scared of fast twist barrels 15 yrs ago I built a 6.5 twist .224 3 groove in a 22 dasher and shoot custom 100 grain uld bullets. I shoot this at 500 yard ground hog shoots and a 1000 yards bench rest match. It shoot excellent in the wind just like a big 300 mag. Point being at 1000 fps I don't think we are stressing the slugs that much. The military seems to think this 300grain 3 twist barrel 1000 fps is a much more effective platform over the 300 subsonic . My 1-26 twist lother wather .510 barrel stabilizes my 650 spire point boat tails just fine. But just because it works doesn't mean to me that it may be more effective with a 1-4 to 1-8 twist. Right now in 2022 you can shoot a Airforce Texan 34 inch barrel African air ordinance upgrade with shoot .510 600 gr+ slugs at over 900 fps. So the technology for air guns is catching up and we do have much lower temperatures and pressure s than powder burners. With a 650 grain .510 slug with a b.c of .5 going 900 fps has over 1000 foot pounds of energy at 300 yards. With helium in a 4500 psi African air ordinance upgrade a 1000 fps should be possible with .510 650 grain . 5 bc ammo. We are at the subsonic super heavy high b.c per caliber thresholds with air guns . The 30 cal African air ordinance upgrade on Texans will shoot the 230 grain slugs close to 900 fps on air same as 300 blackout subsonic.
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I'd have to agree that if someone developed an accurate airgun slug that expands like this 8.6 BLK...
their competition would be so far in the rearview mirror as to be a speck.
their competition would be so far in the rearview mirror as to be a speck.
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