22 Creedmoor light bullet twist

[cgbills]

I am thinking of building a 22 Creedmoor. I do not want to shoot heavies with it and I am looking in the 50’s -60’s grain range. Really what I want is a rifle that will shoot 55’s as flat as possible out to 300-400. Finally since I will be shooting suppressed, I am looking at a 20in barrel to keep the size down.

I know a 22-250s have a steady diet of 55s usually are 1 in 12. However, I would worry about that slow of a twist with a 20in, since it may not be able to spit them out fast enough to stabilize. I know 8 twist is a common 22 Creedmoor rate, but I worry an 8 will spin the 55s too fast. I was thinking a 9 twist would be a good compromise; not spin the 55s too fast when chasing FPS, allow 69gr bullets if I ever felt the need, and provide extra twist to account for the short/decreased velocity of a 20in barrel.

 

[Potsy]

I’d 1:8”.
The 53 V-Max (badass) should take it and it should spin the new Hornady ELD-VT (62 grains, but looong).

 

[Travis224]

I went 1-11 or 1-10 and it's a hammer with 60s at 3700fps. To do it again. A 1-9 would be about perfect in my experience.

 

[Mordamer]

If the goal is 55's as fast as possible I would stay away from a 1:8 twist. No reason to risk blowing up light weight varmint bullets when even a 1:12 will stabilize them fine. 1:9 would be an excellent choice and at Creedmoor speeds will even stabilize a 75 ELD-M.

 

[Renomd]

I went 1-11 or 1-10 and it's a hammer with 60s at 3700fps. To do it again. A 1-9 would be about perfect in my experience.

Hey I saw some of your other posts about your short barrels, you got great success with H4895 and 60gr vmax, what freebore are you running? I was going to order a carbon barrel from preferred barrels, they are using the alpha reamers and I'm between a 0.080" and the .120" freebore reamer for use for the 55-60gr vmax in a 1:9 twist. Also would you mind sharing what brass brand and charge weight you are using w/ H4895?

 

[stello1001]

9 twist

 

[Travis224]

Hey I saw some of your other posts about your short barrels, you got great success with H4895 and 60gr vmax, what freebore are you running? I was going to order a carbon barrel from preferred barrels, they are using the alpha reamers and I'm between a 0.080" and the .120" freebore reamer for use for the 55-60gr vmax in a 1:9 twist. Also would you mind sharing what brass brand and charge weight you are using w/ H4895?

I'm pretty sure it's the .120 FB..60 vmaxes are long enough to work well. As far as the powder charge, I think I was 36 grains...but I worked up until I saw my speed level off and watched my brass real close. I usually take 5 rounds and keep loading them till the printer pockets loosen and with Starline brass, I was 6 loadings or so with SRP. I for sure wouldn't start there, but H4895 seems to be an easy powder with light bullets.

I have since moved to 22 GT and now use 34.0 grains and have no pressure signs and 8 loadings and still going..and only 100-150fps less speed depending on if I have 18" or 20" barrel.

 

[supercorndogs]

If the goal is 55's as fast as possible I would stay away from a 1:8 twist. No reason to risk blowing up light weight varmint bullets when even a 1:12 will stabilize them fine. 1:9 would be an excellent choice and at Creedmoor speeds will even stabilize a 75 ELD-M.

I have heard that shooting faster in the same twist wont make a bullet more stable. I believe there are some more details in the 62g varmint VT hornady bullet thread. I think Litz book was the reference.

A 1 in 12 is plenty for 55s. My 22-250 is 1 in 9. I wonder about the smaller bullets and wonder if their tendency to splash on the surface is made worse by spinning them faster.

 

[Frank Green]

My 22-250 Improved is a 14 twist. Mainly shot 55gr varmint bullets. it was a laser beam on prairie dogs. The 14 twist even with some 60gr bullets will fly from a 223 chamber/velocities. We did a lot of 13 twist AR barrels for varmint guns back in the day with no issues.

My vote would be a 13 or 14 twist with the 22CM.

Running the twist really fast your asking for it. Bullet failure will happen. The hard line in the sand is 300k rpm. As you approach 300k and go over... bullet failure is going to go up especially once you get some rounds/wear going on in the throat area of the chamber. It's going to beat the bullet up more. No way around it and with that kind of RPM your asking the bullets to do stuff that they cannot as forces want to pull them apart.

At 3700fps in a 8 twist barrel your looking at 333k rpm on the bullet. In a 13 twist barrel at 3700rpm your rpm drops to 204,923.

Also really high velocities and fast twist rates... it can also affect the accuracy. If your going to do this the quality of the ammo (as little as possible in the runout of the loaded round) and the quality of the bullet is going to play an important part. Poor quality bullets or ammo with a lot of runout and your asking for accuracy issues.

This was the specific reason why Hornady didn't come out with box ammo for the 22CM. I asked them directly at Shot Show the year they announced brass. The reply back was... we know for a fact someone will start handloading light bullets in a fast twist barrel and they don't want the phone call saying the bullets are coming apart and it's bad bullets. They tested it and confirmed it. That's why they would only make brass when they initially released it.

Fast forward several years now. Its my understanding they will be releasing a factory round with a 80gr bullet only? I don't see them coming out with a light weight bullet though. My .02.

Later, Frank
Bartlein Barrels

 

[Renomd]

Agree w/ @Frank Green.... despite the Berger stability calculators for 50-55gr vmax saying that 14 twist barrels won't stabilize those bullets, they most certainly do for varmint/predator distances in actual practical use ... there is a reason why 22-250s from the factory were classically 14 twist for those bullet weights (and this translates into any caliber whether it's 22-250 or 22CM). 10 to 14 twist for 50-55gr vmax will get it done for sure. I currently shoot a 22-250 with 9 twist and primarily use 50gr vmax, getting 296k rpm @ 3700 fps, and they do great, decent enough accuracy @ 100-300yd to get it done on coyotes; but I'm right at the 300k rpm mark. Some have posted that Hornady has claimed 325k or less should be ok (I've never verified this myself w/ their techs but there are a myriad of posts on here accurate shooter and LRH); but, I prefer to use the <300k rpm mark just to be safe.

So why am I going back to 22 CM (I was one of the earlier adopters in 2017 for PRS/NRL use, and subsequently dumped all 22 calibers for that application and kept it 6BR variant), b/c 22CM can expel a 75-80gr projectile at 3300-3500... which has a near identical drop @ 400yd that a 22-250 55gr bullet going 3700 fps does @ 19.5"; but, the higher weight projectile has 3x the energy, translating to a much better knockdown and lethal and humane end to a varmint, predator, etc... when utilizing a 200yd zero, this translates into a point and shoot situation from 0-300yd without needing to hold over/under for angle of coyote.

 

[Coyote777]

I understand the over RPM but in my experiences with 22creed fast twist shooting lights has been pretty awesome. Like Frank said quality ammo will come into play. My setup is a 16” 1-8t 5R barrel and I shoot both 60g Bergers and 68g Hammer HHT’s with Alpha SRP brass at exactly same speed which is 3440-3445fps. Never had any bullet failures yet but I’m not leaning on the Bergers hard like I am on the Hammers. It is a point and shoot rifle out to 300yds and it is mainly setup as my night/thermal setup.

 

[Frank Green]

Some have posted that Hornady has claimed 325k or less should be ok (I've never verified this myself w/ their techs but there are a myriad of posts on here accurate shooter and LRH); but, I prefer to use the <300k rpm mark just to be safe.

Both the Hornady guys in the ballistic lab have told me approaching 300k and things start to happen. They said more like upper 200k's. I'll say in the 280k to 290k range.

Sierra ballistic lab guy is on the same page. Hard line in the sand is 300k.

I've got a 6.75 twist barrel in 6.5CM on a gun and to date no failures with 140AMAX box ammo, 147's, 150SMK or 135 or 153 Atips. With the 135gr bullets I'm right at 298,666 rpm. I know I'm on borrowed time with the gun.

Why did I do the 6.75 twist? Because we made the test barrels for Sierra when they where working on the 150SMK. The thinking was during development that the 7 twist wasn't going to be fast enough and they were also not seeing the bc numbers they wanted to see with the preproduction bullets which where mid to upper 140gr for weight. So we made them a 6 twist barrel and it told them everything they wanted to see.

So trying to plan ahead I made the 6.75 twist before the bullets where available. All my 6.5 barrels on my guns now are 7.5 twist.