Hotter ammo for “fast twist” barrels

[King_beardsly]

I know “fast twist” barrel are being to become more common place amongst PRS/NRLx shooters that are engaging targets at longer distances, but what I want to know is do you need to run hotter ammo to counteract the extra drag the rifling is imparting.
I’ve heard somewhere that you need to be at least 1080 or better for it to work properly but unfortunately that’s only heard through the grapevine since no one locally seems to run faster then standard 16 twist in their barrels.

 

[KnowNothing256]

@RAVAGE88

 

[King_beardsly]

@RAVAGE88

The man, the myth, the legend…

 

[KnowNothing256]

The man, the myth, the legend…

You wanna know something, ask a mfer that knows..

 

[Emerson0311]

I know “fast twist” barrel are being to become more common place amongst PRS/NRLx shooters that are engaging targets at longer distances, but what I want to know is do you need to run hotter ammo to counteract the extra drag the rifling is imparting.
I’ve heard somewhere that you need to be at least 1080 or better for it to work properly but unfortunately that’s only heard through the grapevine since no one locally seems to run faster then standard 16 twist in their barrels.

No. My 12T barrel tightened my SK Standard + groups at 200+ up by 40% vertically. Best summer velocity for me is about 1060. Cooler is slower, down to around 1000.

 

[King_beardsly]

No. My 12T barrel tightened my SK Standard + groups at 200+ up by 40% vertically. Best summer velocity for me is about 1060. Cooler is slower, down to around 1000.

That’s a nice improvement at distance and think I’m at like 1070 with my current lot of STD+ in summer temps, so might not be an issue

 

[Aftermath]

I know “fast twist” barrel are being to become more common place amongst PRS/NRLx shooters that are engaging targets at longer distances, but what I want to know is do you need to run hotter ammo to counteract the extra drag the rifling is imparting.
I’ve heard somewhere that you need to be at least 1080 or better for it to work properly but unfortunately that’s only heard through the grapevine since no one locally seems to run faster then standard 16 twist in their barrels.

Basically, the answer on "hotter" loads is no.
The faster twist provides extra spin and therefor extra stability at the "slower" or standard velocities. If you stay with the slower twist rate but increase the velocity of the bullet, you can achieve nearly the same thing.

 

[King_beardsly]

Basically, the answer on "hotter" loads is no.
The faster twist provides extra spin and therefor extra stability at the "slower" or standard velocities. If you stay with the slower twist rate but increase the velocity of the bullet, you can achieve nearly the same thing.

So it’s pretty much a wash, I can achieve the added stability either way just a fast twist will do it with a little more ease

 

[CNC-Dude]

Mark and Sam After Work has several .22lr videos where he tested several subsonic and several supersonic factory ammos at 300 yards. The 2 supersonic brands of ammo shot much tighter groups than the subsonic ammo did. One of the supersonic brands was slightly faster than the transonic zone to demonstrate the bullet passing back through it had little to no affect on the accuracy and it produced a better group size than either of the subsonic brands that didn't pass through that zone at all.

 

[Aftermath]

So it’s pretty much a wash, I can achieve the added stability either way just a fast twist will do it with a little more ease

Sorta.
You are discussing rimfire, right?
Finding the velocity required to achieve the same rotation from the 16 twist may not be achievable with the ammo's available. I'd have to do some math but don't care enough to. Also, bullet rotation (spin) is only one of the factors in bullet stability. A projectile can fly too fast and become unstable.
If centerfire, you MIGHT be able to reach the desired velocity but then again, you might not due to pressure. And again, just from the velocity, that projectile might no longer be stable.
Personally, I am very interested in the gain twist stuff.
EDIT to add: When I first picked up my B14r, I tried all the various ammo I had laying around. I can say that it all shot well at 50 yards. At 100, things started to deviate. At 400, the differences were hits on a 15" target or not at all. Even the expensive stuff was not a for sure hit at 400 yards. But it was interesting that this one particular box (lot #?) of CCI MiniMags was a pretty much give me at 400 yards. I don't know it the extra velocity contributed to bullet stability or if that ammo was all real close in velocity. It doesn't matter because I only had that one box of that lot #. I primarily shoot the CCI SV for practice and fun and save the SK and Lapua for when I shoot against my friends for bragging rights and beers.

 

[Boxerglocker]

My 12 twist RimX PVA Lothar Walther is definitely happier above the 1085 Fps mark. Last summer in MO at 90 plus degrees was hammering at 400 yards with SK LRM running 1110 Fps.

 

[grauhanen]

Mark and Sam After Work has several .22lr videos where he tested several subsonic and several supersonic factory ammos at 300 yards. The 2 supersonic brands of ammo shot much tighter groups than the subsonic ammo did

Perhaps their .22LR videos should be viewed with caution. In them it's claimed that faster MV's are much better because faster .22LR bullets are less affected by wind drift than slower ones.

 

[CNC-Dude]

I've never heard him make that claim in that video. He's simply showing that his testing has found the factory supersonic ammo he can purchase and uses produces better groups than the subsonic he has tested. He did say that bullets that are stable to begin with, and not on the verge or edge of stability are simply not affected by passing through the transonic zone as much as people think they are, whether its rimfire or centerfire. And that is why he purposely chose that one particular supersonic ammo that would pass through the transonic zone was to demonstrate that it still traveled another 250 yards without any I'll affects due to having done that. And produced tighter groups than the 2 slower subsonic brands he tested.
He also, in other videos has removed the factory lead projectiles and replaced them with Hornady high BC projectiles of the same weight and gotten better results as well. He has several videos of him shooting those out to 1000 yards. He did change to a faster twist barrel with that testing.

 

[RAVAGE88]

I know “fast twist” barrel are being to become more common place amongst PRS/NRLx shooters that are engaging targets at longer distances, but what I want to know is do you need to run hotter ammo to counteract the extra drag the rifling is imparting.
I’ve heard somewhere that you need to be at least 1080 or better for it to work properly but unfortunately that’s only heard through the grapevine since no one locally seems to run faster then standard 16 twist in their barrels.

Running hotter ammo is generally construed as a cure for various ballistic challenges, but for the 22LR, it's highly unpredictable. So, let's draw a comparison to other rimfire calibers. The 17HM2 and HMR has a different bullet design from the 22LR, as does most of the better performing 22 Mag. Why is this? Very simple....velocity.

It's been proven that increasing the velocity of the 40 gr lead 22LR projectile produces weird downrange performance. This is largely due to the inefficient, low BC design of the projectile. The superior performing 17 cal and 22 Mag bullets are "real" projectiles that were designed to be more efficient at higher velocities. So, in order to increase performance with the 22LR using hotter ammo, it'll need a better projectile to actually perform predictably.

Hope this helps....

MB

 

[King_beardsly]

Running hotter ammo is generally construed as a cure for various ballistic challenges, but for the 22LR, it's highly unpredictable. So, let's draw a comparison to other rimfire calibers. The 17HM2 and HMR has a different bullet design from the 22LR, as does most of the better performing 22 Mag. Why is this? Very simple....velocity.

It's been proven that increasing the velocity of the 40 gr lead 22LR projectile produces weird downrange performance. This is largely due to the inefficient, low BC design of the projectile. The superior performing 17 cal and 22 Mag bullets are "real" projectiles that were designed to be more efficient at higher velocities. So, in order to increase performance with the 22LR using hotter ammo, it'll need a better projectile to actually perform predictably.

Hope this helps....

MB

It does help immensely, so my take away is this if I’m understanding it correctly. The faster 22LR stuff has an inherent issue due to the projectile not being designed for the increased speeds ie. SK HV Match and it’s shotgun like groups, now couple that with an increase in projectile RPM you’ve got a slight recipe for disaster.

That’s where the solid copper stuff from cutting edge comes in with the 42gr and 50gr, it’s designed for the increased speeds along with the increased forces the fast twist rates impart on them since it was designed for that intended purpose instead of just adding speed to a projectile that was never designed for the increased “performance”

 

[grauhanen]

I've never heard him make that claim in that video.

It's possible that a lot of viewers miss it because it intuitively sounds correct. Even the video maker thinks it is.

The poorly informed claim is made in both versions of what's very much the same video. In the more recent version it's made arount the 12:30 minute mark. In the older one it's made around the 15:00 minute mark. The narrator says the faster travelling bullets spend less time in the air and so they face "less conditions" (i.e. wind).