Remington SSA M40 Rate of Twist

[usmc69]

What is the rate of twist of the Remington SSA M40?

 

[mwhite]

What is the rate of twist of the Remington SSA M40?

1in10

 

[MescaBug]

1in10

I dont think so. I believe it is 1:12 like the real deal M40. I'm pretty sure they use the SPS Varmint barrels on the Commemorative, and they are 1:12. They are not custom barrels, they have the same roll stamp as the SPS Varmint.

EDIT: M40 are 1:10, I stand corrected. Not sure about the SSA then ..?

 

[Frank Green]

1in10

Why?

At .308win. Velocities and shooting up to conventional 190gr. bullets a 1-12 will work. A 1-10 isn't necessarily better. Faster twist and the crappier the bullets or the more run out the ammo has typically the groups get worse.

If shooting up to a 190gr. bullet I like a little faster twist like a 1-11 or 1-11.25.

I shoot 155 Lapua and my back up is a 175gr. Sierra. Box ammo is 155gr. Hornady and 168 Hornady Amax. My gun just pounds them. All of my .308win., 7.5x58 and .30-06 guns have a 1-11 or 11.25 twist on them. The exception being my Palma rifle had a 1-12. Why just because. Primary bullet for the palma gun is only a 155gr. which will fly in a 1-13 twist. I've also run 175's thru my palma gun.

Later, Frank
Bartlein Barrels

 

[MescaBug]

Why?

At .308win. Velocities and shooting up to conventional 190gr. bullets a 1-12 will work. A 1-10 isn't necessarily better. Faster twist and the crappier the bullets or the more run out the ammo has typically the groups get worse.

If shooting up to a 190gr. bullet I like a little faster twist like a 1-11 or 1-11.25.

I shoot 155 Lapua and my back up is a 175gr. Sierra. Box ammo is 155gr. Hornady and 168 Hornady Amax. My gun just pounds them.

Later, Frank
Bartlein Barrels

I agree. No real reason for a 1:10 twist. They were shooting 173-175gr M118 ammo at that time. 1:12 is quite sufficient.

Maybe because the previous M70 weapon was 1:10?

 

[M40_A1]

I have always wondered why the Marine Corps went with 1:12 instead of 1:11 since match ammunition was 173 grains. My 1:12 notices the difference.

As an aside, do the Remington M40 commemoratives have the warning message stamped on the barrels?

 

[M40_A1]

Now that is interesting. I guess Remington can no longer blame lawyers as though they are forced to do it on the rest of their rifles. Apparently they have the option not to.

 

[onetopgun]

Bought two M-40 Commemoratives in 2006 from Iron Brigade, SSA02## & SSA01##. Had IBA perform a complete accuracy suite on both weapons prior to shipping (Barrels pulled, Actions trued, Chambers re-cut to 1.630" exact, pillar bedding, triggers tuned and set to 3 3/4 lb-f, etc). Sourced and mounted a new 2nd Generation 3x9 Accu-Range Scope with '66 vintage 4 screw rings and Redfield Jr base on each. Both shoot "lights out" if I do my part with appropriate ammunition.

Just borescoped one and measured the twist at 1 turn in 12. End Flaps on both rifle's carton & Instruction Books are stamped 24" VAR Bbl. Reviewed my e-mail string with IBA when I bought and accurized these weapons and confirmed bbl contour and twist specs. I recall being a bit surprised at the 1 in 12 at the time based on what I had read in the literature (Senich, et al), but IBA maintained that the twist on the original M-40 were 1 in 12 as opposed to 1 in 10.

My personal experience with both weapons is that they love 168's (Old Federal Red Box, Current Production Gold Medal Match, Lake City M-852). but don't seem to like the heavier projectiles as much (Lake City M-118 173 grain). I hunt with both weapons and have had great luck with hand loads using 165 gr Ballistic Tips or 168 gr Berger VLD's loading them as close to M-852 spec as I can get, but would add that when I tried to go to 180 Gr Ballistic Tips that shot great in other weapons with 1-10 twists, the groups from both weapons looked like rat shit in a drawer!

Hope this helps

Regards
JHC