1 in 12 vs. 1 in 10

Papaclaude

Papaclaude

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I have a Remington 700 SPS Varmint with a 1 in 12 twist. Normally, would 1 in 12 stabilize a longer, heavier bullet better or a lighter bullet. The best load I've found yet gives me about 5/8" at 100 yds, using 41 gr. of Varget and 168 Match King with CCI primer in Win. brass. 42 gr. of Varget gives me very similar results (haven't chrono'd them yet). What I would need help with is this: to try to squeeze tighter groups out of it, should I go to a slightly heavier or lighter bullet?:confused:
 
Presume you are refering to 30 cal. 1:12 twist will also stabilize the 175 SMK. Even the longer Berger match bullets of similar weights are OK with 1:12. I am not aware of any theories that would suggest that a faster twist is more accurate? Once a bullet is stabilized, it is stabilized....turning it faster does not make it more stable. I believe it is common for benchrest shooters to use the slowest twist for the bullet length they will shoot....one of the theories for this practice is to reduce the effect of "torque" produced by the faster twist. The only way to determine if the longer bullet will be more accurate is to try it...and it will boil down to what your rifle prefers..the loads you describe lead me to assume you are shooting a 308 Win. With that cal, anything over 175gr SMK's will likely not work too well as you will just lose too much velocity.
You might want to try 155 Berger VLD's as they are longer than the 168 SMK's...so you will be able to get higher velocities and they are stabilzed by a 1:14 twist...which will make your 1:12 do the job easily.
 
12 twists will stabilize every bullet you can possibly shoot from a 308. Period. End of story. One of my team members was until recently when he re-calbered the rifle, was hooting 168SMK and 175SMK bullets from a 14" twist 308 barrel and was winning F-Class matches with it.

The advice to try different length bullets is excellent.
 
Papaclaude said:
I have a Remington 700 SPS Varmint with a 1 in 12 twist. Normally, would 1 in 12 stabilize a longer, heavier bullet better or a lighter bullet. The best load I've found yet gives me about 5/8" at 100 yds, using 41 gr. of Varget and 168 Match King with CCI primer in Win. brass. 42 gr. of Varget gives me very similar results (haven't chrono'd them yet). What I would need help with is this: to try to squeeze tighter groups out of it, should I go to a slightly heavier or lighter bullet?:confused:
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Obtunded has it right. Your twist rate is fine for anything you want to try. A different bullet could well shoot better for you, or you could try changing your charge weights, primer, or even seating depth. Only do one a t a time though!

carsmovies said:
He's talking about a .223 as you can tell by the weights he's already tried.
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I'm guessing not...
 
I'd take the load you have now out to 500 yards, and see if you are happy with the result. I've found that assuming that the load that shoots best at powderburn range will be best at long range is setting yourself up for confusion and heartache.
 
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