I have a heavy barreled .308 Win with 1:12 cut rifling. Any thoughts on how that rate would handle 165 or 168 grain bullets? The gun was billed as a varmint rifle and shoots factory 150 grain bullets well but I wondered if a member or two could offer advice on the accuracy of the heavier bullets.

Thanks.
Matt

Hello,
You have a very fine twist for the caliber/bullet weights you mention. I shot matches, long range, prone, metalic sights for more years than I care to reveal and only variance I had was the Palma barrels were often of 13 twist for the 155 Sierra Palma bullet. Did the 12 twist shoot them OK as well?? you bet and on real windy days, switched to the 190's for wind bucking ability. Not sure your barrel length, but assume it is near 26" but the Palma barrels will be 30" in length and did give one a bit of a boost in velocity which was needed at 1000 yd targets. Check out Sierra's suggested accuracy loads and believe you will find they well know what they are talking about. I don't happen to have an underground test/firing tunnel so they have a wealth of knowledge. Good Luck.

I would think it would actually be even better for 165s and 168s.

dsiteman,

Thanks for your input! I do not handload, for now, and from what I'd read and heard, faster twist rates than 1: 12 were desirable for the heavier bullets. I suspect somewhere there's a performance threshold but was hoping the 165- 168 class bullets would still perform well in my rifle. I do like the option of heavier bullets in my 308.

Thanks again!
Matt

Thanks BigGuy that's good to know!
Matt

My Winchester m70 push feed with shoot just about anything from 100 gr. bullets to the massive (for the .308) 220 gr. Sierra round nose with no problem. The twist rate is 1 in 12". I don't think you'll have a problem with the bullet weights you're looking at.
Paul B.

I have a Model 70(20" barrel) with the same twist rate(1-12). How do you think it would go with 180gn factory gear???

hnts4fun,
your twist will top out with 190 grainers,
heavier bullets will buck wind better but drop faster,and start out slower,
heck try all the weights you want,
enjoy that cut-pipe,
regards

Thanks Paul & jjmp. Trial and error means more shooting time and that can't be a bad thing. Interesting info on the 190s...leaves plenty of room to play.

Thanks all.
Matt

It is the LENGTH of the bullet, not its' weight, that determines how fast a bullet must spin to fly point-on. I think a 1/12 twist is adequate to stabilize a 200-grain spitzer flat-base, and maybe even a 200 gr with a boattail.

I DO know I had no stability problems shooting a 220-grain Hornady round-nose in my pre-64 M70 FWT in .308 Win., and it had a 1/12 twist. My load only produced around 2300 FPS with that bullet, which is 4 diameters long!

I doubt seriously if you'd have any problems at all with ANY 165-168 grain bullet in yours.

El Deguello thank you.

As a non-reloader tiptoeing through the ammo section of a well-stocked sporting goods store, I was trying to avoid making $40 a box mistakes. I'm grateful to all who posted on this thread, who helped me feel more comfortable about the 160 and 168 grain pills. I've hunted all game in my area with a 270 and 130 grain bullets without fail but I wanted to take advantage of the heavier bullets in my "new 308" as we got to know each other this hunting season.

Thank you again!
Matt

Funny Rem used 10" in sporter SS 700 DBM I guess it being billed as a hunting rifle which may be used more often with 180 and heavier bullets vs a varmint/police model that had slower 12 twist, many saying optimize with 168's.

quote:

Originally posted by 6.5BR:
Funny Rem used 10" in sporter SS 700 DBM I guess it being billed as a hunting rifle which may be used more often with 180 and heavier bullets vs a varmint/police model that had slower 12 twist, many saying optimize with 168's.

Maybe. I seem to recall that their 760's in .308 were also cut 1/10.

hnts4fun,from my experience with the 308 rifle,the 1-12 twist is most accurate with 168 grain bullets.I recommend Hornady 168gr boatail hollow points and Vit 140 powder.

For what its worth, my rem 700 P shoots 175gr Sierra match kings the best, followed by 168, then 165. Haven't tried the 150s yet.

John

6.5BR, El Deguello, shootaway, and John;

I'm glad to hear you and others have experienced success shooting 165-175 gr bullets out of 1-12 .308 barrels.

I'm shooting a little used H-S Precision Takedown carrying a 24 inch barrel. I appreciate everyone sharing their thoughts and I look forward to finding the right combination for this rifle.

Matt

The 30-bores have been so throughly worked out that it's very rare to find one where twist detracts from accuracy. Usually the culprit is something else. If your rifle shoots 150's well, it will probably shoot 165/8's even better.

As for the relative speeds, 1:10 is the standard for the 30-06 because you can reasonably expect to use 220-gr. bullets now and then. A few exceptions have been noted, but most 308's are 1:12 since most people top out around 180-200 grains with them. Fast in a 30-bore would be something like 1:8, and would be pretty much pointless.


Okie John