My 6mm Rem model 700 has a twist of 1-9. This rifle shoots 100 grain bullets very well. Usually the 5 shot groups are around 1 inch at 100 yards with 100 grain bullets. When I shoot 85 grain and below with this rifle it is a different story. Groups swell to about 1.75 inches without regard to powder, case, etc. My questions is..is this fast, 1-9 twist good for the heavier 100 grain bullets and BAD for the 85 grain and lighter bullets? Would a fast twist actually make the lighter bullets shoot inaccurately? I realize that a faster twist helps with accuracy with the heavier bullets but have never heard anything about hurting lighter bullet's accuracy. My gun won't shoot the lighter bullets and I would love an explaination. Any help is appreciated.

The 1:9 should not be the problem. I've had several custom 6x45s over the years, and I always use a 1:10 twist --- and I seldom shoot anything heavier than 80 grains. My current barrel -- a Virgin Valley 15" full bull for the Contender -- groups everything from 55 grainers through the 80s I use for hunting extremely well, and most 5-shot groups hover around the half-inch mark. I feel that one can't really overstabilize a bullet (within reason) but that you certainly can understabilize one. Your rifle's lack of accuracy is not the fault of the twist.

I'll disagree only slightly with Bobby, in that I think that a twist substantially faster than necessary to stabilize a given bullet can, very slightly, have a negative influence on accuracy. I would also say that it is a bit easier to get a 75 or 80 grain 6mm to shoot accurately in the old 1-12 twist of the Remington 721 (when it was called a .244) than from the 1-9 Remington 700. But I agree with Bobby that I don't think that's the factor which is causing your groups to nearly double when going from a 100 to an 85.

My suggestion would be to play around with seating depth. While I like most bullets seated as close to the lands as possible, lighter bullets sometimes perform better with a little freebore.

Incidentally, I own a 721 .244 with the 1-12 twist. It is marvelous with bullets from 65 through 90 grains, but 100 grainers turn sideways every time. Too slow twist is obviously more problematic for accuracy that too fast twist.

Stonecreek is right that "over-stabilized" bullets, and the 1./9 is way faster than needed for an 85-grainer, can suffer reduced accuracy. A lot depends on how dynamically balanced (concentric) the bullet is. Some light bullet could probably be found for your rifle that would be more accurate than 1.75". In addition, loading them to a lower velocity MIGHT (maybe yes, maybe no) help also, but then, of course, you are sacrificing ballistic performance to improve accuracy.

I'm going to align my opinion with that of Bobby. What the faster twist MIGHT mean is that you have to try a few more powder/bullet combinations for a given bullet weight in order to find one that shoots. We could get into a whole discussion about a given twist rate being *adequate* or *optimal* for a given bullet weight. Don't give up so quickly, if the rifle will shoot accurately I'm sure you can find a good load for most any bullet weight you wish to shoot.

Hey harkm

You can send all those awful bullets to me!

I have a 6 Rem I set up to shoot 105, 107, et al with a 1-8" twist. It also happens to shoot the 58 V-Max's into little snarly bugholes. Go figure! I doubt your twist rate is the problem, really. Fool with your seating depth and I bet they work better.

Redial

Thanks for the info. Maybe you guys are right and it isn't the rate of twist. I guess this is good news! More trips to the range! Redial, if your 1-8" twist rifle shoots 58 grainers then it must just be my rifle.

[ 10-11-2002, 21:28: Message edited by: harkm ]

Harkm,
I will second Redial. I have a 243AI (Case capacity much like your 6mm) with a 1:8 twist barrel and I have no problem shooting the lighter 6mm bullets.

Normally, inaccuracy due to spinning the bullets faster than optimal, shows up at longer ranges when the bullet fails to "nose over" and follow the arch of its trajectory.

I know you don't want to hear this but it would probably help your accuracy to slow the bullets down a bit.

My little old 6mm Rem shoots 95 & 100 grain bullets very well. Also the 105 Speer shoots well. Not as accurate with 55 grain ballistic tips or 60 grain Sierra hollowpoints, but not bad. Good enough for 300 yard varminting! I don't think the 1:9 twist is the problem, Guy

Lighter bullets tend to have thinner jackets and the lighter the bullet the more contact with the rifeling and the more opportunity to stress the bullet by driving it to fast.....my reasoning may be wrong but the small amount of experience I have in this area strongly suggest slowing the bullet down BUT if it were me I would get rid of the light bullets and go to heavier ones that suit the twist of the barrel...bullets are relatively cheap...even the expensive ones.