Thread: Is there a down side to fast twist barrels?

Say if one wanted a 6mm barrel chambered in a moderate chambering, is there a down side in using a barrel that has a twist rate from the upper end of the spectrum? Say 1:7"?

By my play on JBM it seams to make it more stable. but at a guess there would be a limit to how fast you could spin it before roasting the copper. then theres monolithic where you wouldnt have the worry of the bullet destroying its self

More friction, lower speed, maybe more fouling, over spinning some bullets (can fly apart).

Originally Posted by Wildman

Say if one wanted a 6mm barrel chambered in a moderate chambering, is there a down side in using a barrel that has a twist rate from the upper end of the spectrum? Say 1:7"?

Not with a moderate chamber.

I wouldn't want to try 40 grainers at 4500fps in my 1-7, 22-243.

The 53 Vmax goes fantastic in 1-8 twist 22 Terminator at 3700fps

Originally Posted by Beavis

More friction, lower speed, maybe more fouling, over spinning some bullets (can fly apart).

What he said...

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Hmm thanks guys.

But I'm guessing that wouldn't be as much of an issue with projectiles needing almost as fast a twist, say 1:8" or 1:9"?

If your goal is to stabilize long bullets then the cons aren't really relevant.

And a bit of rpm really adds to the damage on the animals

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Best to slightly over spin (stabilise) a projectile than the over way. If you need a 1 in 9 but use a 1 in 8 then all good. But if you only need a 1 in 12 and use a 1 in 7 then the cons above would apply. If you are going to the trouble of rebarreling something then you should use an appropriate twist for the projectile you plan to use

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Some projectiles redesigned or require a fast twist i.e. Barnes.

Speaking from experience (think expensive, hard learnt lessons) use the slowest twist barrel that will stabilise the heaviest bullets that you intend to shoot. Using a faster twist where not required limits velocity & on occasion accuracy as well. The difference a faster twist makes on projectile expansion is sweet F#&k all!

The difference a faster twist makes on projectile expansion is sweet F#&k all!

This is true. There is a myth about that driving a bullet faster in a slow twist barrel will stabilize a bullet better - not true. Some bullet shapes will be slightly more stable at higher velocities but others not. However there is a big difference with bullets that go transonic within the target range and some subsonic bullets shapes require more stabilization but not all. This is why subsonic 22lr's are more accurate than HV's.