.224 bullet weights for 1 in 12 twist

[Black Snowman]

What bullet weights should a 1 in 12 twist stabalize?

Seem slow for a .224 bore rifle? You're right. The reason I ask is I'm considering getting some of the 30 cal sabots and trying them out in my CZ 550 and seeing how they do. I know lots of people lose accuracy on the sabots and I can't help think that part of it is the slower twist rates.

I can't remember if slower is lighter or slower is heavier for bullet weights. I was thinking that you needed a faster twist for the heavier bullets. The data is for 55 gr bullets but that seems like it wouldn't stabalize as well as something futher tward one end or the other of the spectrum.

Muzzle velocity should be about 4000 FPS once I have the loads worked up if it makes any differance.

 

[Dave Markowitz]

Everything else being equal, you need a faster twist the heavier the bullet. E.g., the twist used in the M16 and M16A1 was 1 in 12", and was appropriate to a 55 grain bullet with a MV around 3000 FPS. When the military went to heavier, longer bullets in the 5.56mm, they increased the twist to 1 in 7" on the M16A2. (A 1:9 twist will stabilze 62 grain M855 Ball, but the slightly faster twist is needed for tracers.)

Since you'll be shooting your .224 bullets in sabots in a .30 caliber bore, at a much higher MV than the 5.56 NATO, you should be able to use bullets heavier than 55 grains. How heavy, I can't say though.

 

[nipprdog]

I have a 223 NEF handi rifle that is 1in12.

they recommend best results will come with bullets 55gr and under.

one of the most popular loads for us non-reloaders is the winchester 45gr varmint load.

YMMV.

 

[JohnKSa]

A lot of commercial .223 rifles are 1:12 twist.

My 1:12 twist .223 T/C Encore will put 3 Black Hills 52gr MHP bullets into less than half an inch @ 100 yards.

Conventional wisdom says 1:12 is good for 55 grains or lighter.

 

[Black Snowman]

Great, that's just the info I was looking for. I have a few hundred pull-down 55 gr FMJ I would probably use in conjuction with this experiment and my Dad was generous enough to give me his old powder stash so that's already paid for as well. The $20 "starter kit" seems worth it to me for the fun of trying this out since I won't have any other expenses. I'll be sure to post my results.