can i use 168 grain .308 bullets with a 1 in 10 twist rate?

[gotguns?]

or is there another weight that will work better? is there a rule of thumb reguarding twist rates?

[Unclenick]

The 10" twist in '03 Springfields and M1 Garands shot the 168 grain Sierra MatchKings well for many years. It's not a problem, but they can't get much beyond 700 yards in those guns before the start tumbling. They become unstable as they drop to near the speed of sound. The 175 grain Sierra MatchKing does not lose stability and is a better choice for shooting beyond that distance.

If you have Excel or the free Open Office Suite on your computer, you can download a twist estimator from my file repository. It is a modernized and updated version of the Greenhill formula devised by Don Miller, who was one of the late Robert McCoy's colleagues. It is intended to help you choose a barrel twist for a particular bullet, but can be used to evaluate a twist you have, as well. It requires you to enter the diameter, weight, length, and speed of the bullet, and optionally you may enter the air temperature and barometric pressure and your existing barrel twist to see how well it works for that bullet?

To be stable, a bullet must receive a gyroscopic stability factor, s, with a value greater than 1. Optimally it will be between 1.4 and 1.5, but it will be stable anywhere above 1 until you spin it so fast it comes apart or the core slips in the jacket from the rotational acceleration. 1.4 to 1.5 are considered optimal values for best accuracy by Harold Vaughn and Don Miller, respectively, This is all explained in the instructions above the calculation information entry windows. The output it gives you is the twist you need to get the ideal s value and also the s value you have from whatever barrel twist you enter.

[kraigwy]

LC 852 is the NM (Match) load used by the military for M-14s/M1As which are 1-10 twist. 852 uses the Ser 168 Grn Bullet pushing it at the standard of 2550 FPS. Is a shooter, it works in 1and 10 twist.

I use it in my Heavy Match M1A and have been since the late 70s in High Power matches. The only exception would be when the military issued M118 for the match I was shooting in, OR, I was shooting a 1000 yard service rifle match and then I'd use the 180 SMK (the older one, not its the 175 SMK).

Hope that answers you question about 168s in 1-10 barrels.

Now for Mr Greenhill. Using his fomuilar you'll see that the 30 cal 168 calls for a 1 in 11. It's close enough to 1 in 10, yet allows you to use the heavier bullet for long range shooting and/or faster velocity

Devided the bullet lenght by the cal or (for the 168 SMK)

1.212 / .30 = 4.04

then devided 150 (costant for lead core jacketed bullets) by the above answer

150 / 4.04 = 37.13

Mutiply that number by the Cal or

37.13 / .30 = 11.13 or 1 in 11.

If you were to only shoot 168s at 600 yards or less. you could get buy with the 1 -11, Most barrel makers use 1 - 10, to give you flexability and you really wont see much differance between the two unless you went to heavier bullets.

Most of the record set by the 308 at Perry were set by the 1 in 10.

I would bet you that if you took idenatical guns except for the twist ( 1-10 vs 1 -11) there isnt a person in TFL how could tell the differance shooting 168s. Neigher is gonna help the 168 @ 1000 yards.

To make a long story short, dont get hung up on math. You're time would be better spent on the range putting rounds down range, thats gonna help you more then switching between 1-10 and 1-11.

Too many people try to math or gimic their way to success.

[gotguns?]

Thanks you guys answered my question very well

[Nnobby45]

Had my old M700 (1963 w/20" bbl.) 30-06 rebuilt with new Krieger 24" bbl. set up for 1 in 11" twist. The rifle smith who built it says 190 spitzers are about the limit, but may be on the slow side. 220 rd. nose are ok, but not spitzers.

The 1 in 11" twist is set up primarily for 150 to 180 gr. spitzer style bullets.

The 1 in 10 standard is set up for most all commercial ammo, including the harder to stabilize spitzers (because they're longer). 220 gr RN are easily stabilized, but don't know about spitzers.

The 168 gr. would be easily stabilized, but for extreme long range, would be inferior, as mentioned, to heavier bullets with better BC. Don't think it's the twist that's the issue.

Mine is a hunting rifle, not designed for long range target competition.

[velocette]

You sure can. Try about 41.5 (+ / - ) gr of IMR 4895 in RP brass with a WW primer & look out for sub moa groups. Great combination in a .308.

Roger