Thread: Can twist rate be too fast?

I've often heard about twist rate being too slow for heavy projectiles, but what about too fast for light projectiles? I'm thinking .308 16.5 inch barrel with 1:8 twist and 125gr projectiles? Cheers.

Go to the extreme and bullets can blow up mid flight if they are massively over-spun.

Faster than necessary can be a bit detrimental to accuracy, on average. Bullets behave a little like car wheels - unless they're perfectly balanced around their axis, they wobble. The faster they spin, the more they wobble.

Depends on how fast you you are trying to send them, if you have gone light to achieve speed (16 inch barrel) then that could be counter intuitive. Can try but probably find best accuracy at slower speeds. But I’m bent towards the other way, heavy pill better BC slower but still perform at distant.

Iv heard from mitch maxbury that there were bullets that blew up mid flight in 308 target shooting if certian bullets were spun too fast

Its going to be interesting as 8.6blackout becomes more availble if the 1-3 twist is going to cause it with supersonic bullets

In practical terms the answer is no. I doubt if you can spin the 125 grain pills fast enough to fall to bits in your 16.5 inch barrel. There is a persistant myth that projectiles become less accurate if they are spun too fast which may have been true years ago with the poor quality projectiles available at that time but not today. Still myths die hard in the US and have been responsible for the slow twists used there right up until recently. No doubt there are limits but you are nowhere near them. Your limit on accuracy may be affected more by how far from the rifling you need to seat the projectles. Recent .308 rifles seem to have shorter throats than previously. My .308 has a long throat and shoots flat base projectiles better than boat tails due to the long throat. Forget about your barrel twist, it is a non issue.
Regards Grandpamac.

Originally Posted by Bill999

Iv heard from mitch maxbury that there were bullets that blew up mid flight in 308 target shooting if certian bullets were spun too fast

Its going to be interesting as 8.6blackout becomes more availble if the 1-3 twist is going to cause it with supersonic bullets

I've seen that people are suggesting sticking to bonded or monolithic bullets with that one to avoid them coming apart. Even more interesting is the insane amount of spin drift such a high twist creates. X-Ring on YT was needing to hold 2 whole mils at 700 yards with subs.

Yep, what he just said! I have seen phenomenal accuracy out of quick twist barrels using light for caliber bullets.
Main thing is bullet quality, if the bullet is made with "lesser " quality jackets (meaning bullet metals used & variation in jacket walls thickness) it creates effectively an out of balance wheel effect.
Faster it is spun the worse the wobble from the balance, just like an out of balance car wheel. Faster you drive the worse it gets.
Top quality bullets counter this problem.
Good quality bullets are fine in quick twist barrels in other words.

Originally Posted by TARGEX

Yep, what he just said! I have seen phenomenal accuracy out of quick twist barrels using light for caliber bullets.
Main thing is bullet quality, if the bullet is made with "lesser " quality jackets (meaning bullet metals used & variation in jacket walls thickness) it creates effectively an out of balance wheel effect.
Faster it is spun the worse the wobble from the balance, just like an out of balance car wheel. Faster you drive the worse it gets.
Top quality bullets counter this problem.
Good quality bullets are fine in quick twist barrels in other words.

I agree with @TARGEX assertion fully. On Sunday 3 of his 70 grain 6mm bullets shot through a 1/8 twist formed a cluster that was barely more than a bullet diameter wide...

The annoying thing about that is that it wasn't me driving my rifle!

slow it down and you should be ok.........

Iv got some varmit tnt bullets that specify no faster than 1-12 twist

They are super frangible so I don’t doubt they could cause problems
They went fine in my1-10 but I’m not game to try them in my 1-8


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years back I had hornady spsx 50 grn pills for my .223 they were for velocity less than 3100fps......man they were the berries on wallabies,big mess....sort of like the vmax/zmax do now.... from memory there was no twist rate mentioned back then....it just wasnt a "thing"....if you think about it,the speedsters like 22-250 had a slower twist assumably to be less hard on projectiles...so flip that on head and slowing them down in fast twist should make sence...

Just started running the 50g TNT in my 1:9 22-250. Early stages of development but min book charge and they're holding together so far, won't be looking to go full speed just incase. About 3500fps currently. Should blow some critters up

Originally Posted by Micky Duck

.....if you think about it,the speedsters like 22-250 had a slower twist assumably to be less hard on projectiles.....

No, it's simply that at that point in history, the ballistic advantage of more slippery projectiles wasn't fully appreciated. That's why the 1-in-12tw Rem .244 was toast after the .243W with its much faster twist came out. The 6mm Rem sorted that but the damage was done. Shame as the 6Rem is a far better cartridge.

I remember reading about long range 2506 rifles. They were specially made with extra long throats, 1 in12 or 1 in 13 twist and 26 - 28 inch barrels. Faster speeds could be gained with a slower twist than a standard or fast twist.

Originally Posted by Steelisreal

I agree with @TARGEX assertion fully. On Sunday 3 of his 70 grain 6mm bullets shot through a 1/8 twist formed a cluster that was barely more than a bullet diameter wide...

The annoying thing about that is that it wasn't me driving my rifle!

Don't you just hate it when that happens?
GPM.