Are the .223 and .22-250 Barrels Interchangeable?

[cpurick]

Would the increase in speed from the .22-250 shred the jacket on the bullet? Is 9 about as fast as you'd want to go with the 250? Seems like it would push it faster than it would want to spin in the case of 8s and 7s...

Serious question, kinda new to this...

If a rifle is faster you can get away with less twist, since the goal is spin over time rather than spin over distance. So in theory you can stabilize the same bullet with a 7" twist on a .223 and an 8" twist on a .22-250, and in practice the .223 will usually have faster rifling.

Also, as the bullet gets longer and heavier it naturally gets slower. Furthermore, a longer bullet will displace some powder in the cartridge. This means the the twist needs to be even tighter than the increased length of the bullet alone suggests, because less powder and more weight translate into lower velocities as well. You can launch a heavier bullet slower, but you still have to spin it at a minimum rate, and that rate is faster for a longer bullet.

You do hear occasional reports of jacket failures though, and .223 owners often look forward to longer barrel life. AccurateShooter.com says 9" is a good all-around twist for the .22-250 since it can push some of the caliber's higher-BC bullets, though the heaviest .224 bullets still require an even faster 8" twist. Sierra says their 90 grain SMK wants a 6.5" twist, and the Bergen 90 VLD requires a 7 twist. If we assume those values are calculated for .223 velocities, I'd consider investigating whether a .22-250 can get away with slower twist rates.

Where you really start to run into problems are the cases where a barrel is rifled for 90 grain bullets, and the shooter is using 4000fps 45 grain pills with it. This is where you're gonna find bullets disintegrating out of the barrel. The bullet was never designed for that much spin, and the barrel was never intended for that much velocity. The idea is that you generally don't buy a custom barrel to shoot factory ammo.