Twist Rate and Bullet Weight: 30-06 and .223 [Archive] - Glock Talk

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JohnW1963
01-23-2010, 09:44
I'm a newbie and was wondering about twist rate and bullet weight for the 30-06 and the .223. My two 30-06 rifles are an M1 Garand and a 1903A3 which from what I have found are both 1-10". My .223 is a 1-7". From what I've seen so far, the 1-7" is supposed to be better with heavier bullets, like 69 gr or 75 gr. Is that correct? Is it even better with heavier grained bullets like 80-90 gr? Or, are those too heavy?

Also, on the 1-10" 30-06's I was thinking 168 gr, but can't find any source for the best weight for that twist rate. Does anybody have a good source for bullet weight and twist rate research? What have you found works best in a 1-10" 30-06?

I have Lyman's 49th and didn't see anything in there re: twist rate and have Hornady, Speer and Sierra's reloading books on order, but I am impatient and thought I'd ask.

Thanks for any feedback. <!-- / message --><!-- BEGIN TEMPLATE: ad_showthread_firstpost_sig --><!-- END TEMPLATE: ad_showthread_firstpost_sig --><!-- sig -->

Patrick Graham
01-23-2010, 12:01
I used to do a lot of experimenting with different loads for my Garands when I first got them almost 20 years ago.

After several years and a few OP rods I'm back to basics with the 150gr Spire Point M2 Ball load and the 172gr M72 match load.

PCJim
01-23-2010, 21:50
I cannot comment on the 30-06, but you are correct on the 1:7" twist of the .223. If you use the search function, this was just identified during discussion in another thread just this week.

dudel
01-24-2010, 04:53
I'm a newbie and was wondering about twist rate and bullet weight for the 30-06 and the .223. My two 30-06 rifles are an M1 Garand and a 1903A3 which from what I have found are both 1-10". My .223 is a 1-7". From what I've seen so far, the 1-7" is supposed to be better with heavier bullets, like 69 gr or 75 gr. Is that correct? Is it even better with heavier grained bullets like 80-90 gr? Or, are those too heavy?
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Can't comment on the 30-06, but you are spot on on the .223. I'm not sure it's "better" with 80-90, but 1:7 should be able to stablilize those.

One thing to keep in mind with the heavier projectiles, is that they tend to be longer than the lighter ones. With Varget, my .223 case are filled up to a good degree. I think if I used something heavier than 55gr (I've got a 1:9 twist), I could end up compressing powder. There's not much to play with regarding COL (especially if the projectile has a chanelure).