22 Creedmoor twist rate

[jfjohn77]

I am currently having an X-Caliber barrel with a 6.5 twist rate chambered in 22 Creedmoor. I already had the barrel blank. I have never had a 22 Creedmoor and I am curious as to what the lightest bullet weight that it could reliably be expected to stabilize.

 

[B23]

A 6.5tw 22 CM will have no problem stabilizing any 22 cal bullet on the market. Now, will they all make it to the target before they fly apart, not likely.

That's a lot of twist in a cartridge capable of some pretty high velocities, particularly, with the lighter bullet weights so with light bullets you could easily be well over 400,000 RPM which is a sh$t ton. I don't know many bullets, except maybe solids, that'll hold together spinning them that fast.

With that fast of a twist If you want to shoot lighter bullet weights I'd probably talk to some of the places like Cutting Edge or Barnes that offer lead free and lathe turned solid copper bullets. Hell, even with 80 grainers you'll probably be around 350,000+ so the solids may be your only option.

 

[SloppyJ]

I think you're in mono territory there. What was your plan for the barrel?

I see no reason not to shoot heavies in a 22cm, that's where all of the benefit lies.

 

[Stocky]

6.5t twist seems excessive what's the plan projectile wise

 

[Axlrod]

I have an x-caliber 7 twist in 22 Creed and 88 grain Hornady's come apart. 95 gr. SMK's might work or monos.

 

[SloppyJ]

I have an x-caliber 7 twist in 22 Creed and 88 grain Hornady's come apart. 95 gr. SMK's might work or monos.

I haven't done a ton of research on it but the 7 twist blowing up the 88s surprised me a bit. How far down range are they going? I'd hate to have one blow out a suppressor.

 

[Axlrod]

I haven't done a ton of research on it but the 7 twist blowing up the 88s surprised me a bit. How far down range are they going? I'd hate to have one blow out a suppressor.

I don't know how far, they don't make it 100 yards. I didn't put my can on it and I wouldn't. 85.5 gr Bergers also explode, but less of them than 88 Hornady. It's a 27" barrel, and started doing this when new.

 

[waspocrew]

6.5 twist is definitely on the fast side.... even my 7.5 twist handles the 95 SMKs. I think you're basically looking at monos - guys have had the 95 SMK blow up with a 7 twist.

 

[jfjohn77]

Well I was planning on shooting heavies, but I was just curious about lighter bullets. I read different articles along with Peterson's testing data, and they were all using 7 twist. I was hoping to be able to use this blank only because I had it.

 

[Stocky]

Well I was planning on shooting heavies, but I was just curious about lighter bullets. I read different articles along with Peterson's testing data, and they were all using 7 twist. I was hoping to be able to use this blank only because I had it.

Definitely dont need a 6.5 twist for heavies. Its not unknown for 7 twists to blow up 88 elds and 95smks (which are some of the heaviest) 88s will stabalize in an 8 twist in ALMOST all conditions down to sea level at Creedmoor Velocities). I would get a 7.5 if i had a choice.

 

[HandgunHTR]

I don't know how far, they don't make it 100 yards. I didn't put my can on it and I wouldn't. 85.5 gr Bergers also explode, but less of them than 88 Hornady. It's a 27" barrel, and started doing this when new.

That is weird. Do you have a borescope? I would be looking to see if there is something that is affecting the bullet before it leaves the barrel.

A 7-twist shouldn't have 88s coming apart unless you are pushing them into dangerous pressure territory.

 

[Duh]

Anyone have issues with bullets coming apart with the 7.5 twist? I just ordered a 20 inch 7:5 twist for an sig cross.

Was wanting to run the 88’s around 3200fps

 

[jfjohn77]

What brand of bullets and at what velocities are you fellows experiencing your bullets coming apart? In checking the Berger Twist Rate Stability Calculator, I don't find any issues even going down to their 80gr with a 6.5 tw at 3525 fps.

 

[waspocrew]

Anyone have issues with bullets coming apart with the 7.5 twist? I just ordered a 20 inch 7:5 twist for an sig cross.

Was wanting to run the 88’s around 3200fps

No issues with bullet failure in my 7.5 twist. I have the 62 gr ELDVT up to 3679 and they make it to the target just fine. My 88s are going close to 3200 and kill well.

 

[jfjohn77]

In the Peterson load data, it states that Sierra recommends a twist rate of 1 in 6.5” or faster for barrels shooting their 95gr HPBT. So I'm a little confused here.

 

[waspocrew]

What brand of bullets and at what velocities are you fellows experiencing your bullets coming apart? In checking the Berger Twist Rate Stability Calculator, I don't find any issues even going down to their 80gr with a 6.5 tw at 3525 fps.

It’s not a matter of stability, it’s RPMs that are the issue. Google “bullet RPM formula”. You run into issues when your RPMs are above ~ 300k or more.

 

[waspocrew]

In the Peterson load data, it states that Sierra recommends a twist rate of 1 in 6.5” or faster for barrels shooting there 95gr HPBT. So I'm a little confused here.

You need that twist rate for a cartridge with a much slower velocity. 22 Creed has tons of horsepower, so you don’t need as fast of twist to stabilize the 95 SMK. The 95 shoots great in my 7.5 twist.

 

[Duh]

No issues with bullet failure in my 7.5 twist. I have the 62 gr ELDVT up to 3679 and they make it to the target just fine. My 88s are going close to 3200 and kill well.

Awesome! I was wanting to shoot the 62s as well so that’s great to hear. What powder are you using for the 62s?

 

[waspocrew]

Awesome! I was wanting to shoot the 62s as well so that’s great to hear. What powder are you using for the 62s?

So far I’ve only tried Varget. I’ll just stick with that since it shot so well.

 

[Duh]

So far I’ve only tried Varget. I’ll just stick with that since it shot so well.

Gotcha. I’ve got plenty of that and 4350 so I’ll get to loading as soon as I get the gun put together. Thanks