Guys, I ran into a .30-06 with a (somewhat unusual?) twist rate of 1-11". Shilen's twist rate information ( Shilen Twistrates, Courtesy of Bencrest.com ) does not list the 1-11" option. It does list 1-12" (max 170 grs) and 1-10" (max 220 grs).

Now, I know that in reality it is bullet length as opposed to bullet weight that is the determining factor, but unfortunately my bullet boxes don't specify length... What do you think a 1-11" twist will stabilize??

- mike

Sako and Tikka both have their .30 caliber chamberings with 1-11" twist rates. My Tikkas in .308 Win and .300 Win Mag will generally stabalize bullet weights up to 200 grains. I have not tried bullets weighing more than 190 grains in my .308 Win or more than 200 grains in my .300 Win Mag but have had no problems with accuracy at that those weights. Stability for a given twist rate depends on a combination of bullet weight, length and the velocity at which it is fired. Hope this helps.

TreeFarmer

My -06 with a Shilen 1:12 does best with a 150gr NBT (at 3000fps), and OK with a 165gr bullet, if that helps you.
Off hand I'd say youd get your best results by staying under 180gr.
Remember that none of the twist charts take VELOCITY into account, what bullet works best for a 30-30 1:10 is different than the one that works best in a 300RUM 1:10.

This is interesting since I once read a piece by either Julian Hatcher or Townsend Whelen describing an "accident" that happened at Springfield Armory once in which a rifling machine had "skipped a gear" and made a number of '03 Springfield barrels with a 1/11" twist. The way this was discovered was that a certain lot of '03's were a lot more accurate than the average rifles. Investigation as to what was causing this finally discovered the twist rate in this batch of rifles was 1/11" rather than 1/10"!



Naturally, the Army "repaired" the machine to making the "correct" twist of 1/10", despite the fact that the 1/11" rate produced a better-shooting rifle! I don't recall which G.I. bullet was in use at that time, the 1906 150-grain flatbase or the M1 172 grain boattail.

Thanks guys - it eased my mind that the Sakos also come in 1-11". I thought 1-10" was the standard - you live and you learn, I suppose.
- mike

I've seen fantastic accuracy with .30 cal 1-11'' twist, in several .300s including 300 weatherbys with the 200 grain Accubond.

J. O'Connor's favorite 30-06 he often mentioned had a 1-12" twist...

That is interesting, because the Accubonds are supposed to be very long bullets. I was hoping to be able to shoot 180 grs Accubonds in the .30-06 - or even up to 200 grs NPs. I doubt I'll shoot 220 grs. In any event, the statement about the 200 grs Accubonds in 1-11" is encouraging!
- mike

I my opinion a 11 inch twilst will stabilize anything up to 220 gr. I have shot 180 gr Sierra Match kings in my 13.8" twist 30" Krieger at 2670 fps with fantastic accuracy (5/8 of inch at 200 yds - 5 shots).

MHO,
I once had a 30 caliber barrel with a 1 in 16 twist. I ended up with it in a batch of barrels that I purchased a few years ago. I eventually gave it to a bench rest shooter and he is going to put it on a .30 that shoots a 110 grain bullet. It was also a barrel from a long dead, very good maker and he is tickled and I am glad it is out of my hands and in those where it might be used.