Range Report USMC twist rate test?

[memilanuk]

I was listening to a podcast recently, and there was mention of a Marine Corp study/test on twist rate out to at least 1k. Bits and pieces of the conversation implied that they came up with an 7.75 or 8 twist being optimal for a 185 Juggernaut... out of a .308 Win.

I'm curious if anyone here knows where I can find more info on this study? Was it released to the public?

 

[Lowlight]

Try Schneider,

I don't think it was ever posted, but they felt 8 Twist was optimal under the conditions they shot.

I don't know the specs, I think the rifle was 18" or 20" though

I personally saw a lot of fliers with an 8 twist 308, especially close up.

 

[memilanuk]

Hey Frank,

The topic kind of intrigued me, as most people I know competing with 200 gn Bergers @ 1k in FTR have pretty much settled on 10 twist for a balance of accuracy and stability/BC. The newer S200MKs, being considerably longer, will shoot okay from a 10, but need a 9.5 or 9 to get all the BC that you paid for - according to what I hear. That someone had better luck with an ~8 twist for 185s is kinda crazy - but the shorter barrel / lower MV is probably a factor there?

Thanks for the lead

Monte

 

[Lowlight]

Yes,

You can add twist to make up for lack of MV, which is what I believe they did.

I agree and use 1-10 for pretty much everything to balance speed and twist and have never seen it let me down.

I tried the 8 twist 308 and abandoned it pretty fast, I did not like the results.

My 20" AI 308 loves the 185gr and I get 2700fps using 46gr 2000MR, it's a 1-10, zero issues with great LR accuracy

The military listened to the wrong guys and tried over twisting everything, i don't think it works as advertised.

 

[pitdog85]

I was listening to the aussie precision pod cast where they interviewed Todd Hodnett. I'm pretty sure he was saying he consults to the military and he was the person pushing them to go with the fast and faster twists. Frank can probably confirm that.

The current F class open world champ from Australia says to go with the least twist you can get away with for the bullet and distance you are shooting.

 

[308Gunner]

I have a 18" 1-10 and it shoots lights out I shoot it out to 1K but it is not my first choice for that distance. I have a 1-7 on my 6.5SLR but I did that knowing that the if I should choose to shoot the 147 to 150 class bullet that it would stabilize it, and since my barrel is 22" I cant get the speed of a 24 to 26" tube.

 

[_Windrider_]

Yes,

You can add twist to make up for lack of MV, which is what I believe they did.

I agree and use 1-10 for pretty much everything to balance speed and twist and have never seen it let me down.

I tried the 8 twist 308 and abandoned it pretty fast, I did not like the results.

My 20" AI 308 loves the 185gr and I get 2700fps using 46gr 2000MR, it's a 1-10, zero issues with great LR accuracy

The military listened to the wrong guys and tried over twisting everything, i don't think it works as advertised.

TH strikes again!!!

 

[308pirate]

I was listening to the aussie precision pod cast where they interviewed Todd Hodnett. I'm pretty sure he was saying he consults to the military and he was the person pushing them to go with the fast and faster twists.

 

[Bulletsmith]

I have used 1-7.7 and currently use a 1-8 5r bartlein. 22in long with a standard 308 Winchester chamber. I shoot it with 185gr projos from several different mfg. all have shown very good accuracy from close range 100yds. to over 1000yds. I have seen a little more drift to the right but noting to bad.

 

[Shadow_Warrior]

I have used 1-7.7 and currently use a 1-8 5r bartlein. 22in long with a standard 308 Winchester chamber. I shoot it with 185gr projos from several different mfg. all have shown very good accuracy from close range 100yds. to over 1000yds. I have seen a little more drift to the right but noting to bad.

I'd be curious to know what your load data and confirmed velocity is with this combo?