Print Page | Close Window

1:8 Twist 308 Win

Printed From: OpticsTalk by SWFA, Inc.
Category: Firearms, Bows, and Ammunition
Forum Name: Reloading & Ballistics
Forum Description: Anything to do with ammunition
Printed Date: December/10/2018 at 10:23

Topic: 1:8 Twist 308 Win
Posted By: nralifer
Subject: 1:8 Twist 308 Win
Date Posted: February/11/2018 at 04:27
Testing this weekend a wild hair idea of chambering a 308 Win in an 8 twist 18 inch barrel to have a gun that has the power of a 3006 and can shoot subsonic and use a 6" suppressor.  So far I have gotten average 2947 fps using the 155 Palma bullet with WLRM primers and 49 gr  Leverevolution. The subsonic load is a 204 gr ICBM in front of 15 gr Trail Boss ignited with the WLRM primer generating an MV of 1081 fps.

It is hard to fail, but it is worse never to have tried to succeed. TR

Posted By: Kickboxer
Date Posted: February/11/2018 at 07:27
Wow... outstanding.  You know, you are going to force me to start reloading again, yet...

Opinion,untempered by fact,is ignorance.

There are some who do not fear death... for they are more afraid of not really living

Posted By: koshkin
Date Posted: February/11/2018 at 12:58
2947fps out of a 18" 308Win barrel with a 155gr bullet?  

That's faster than is typical for a 24" barrel with 155gr bullets.

One of these days you will blow yourself up.  I've had a rifle blow up in my hands once and I did not enjoy that one bit.


------------- - - Facebook
The greatest obstacle to discovery is the illusion of knowledge

Posted By: SVT_Tactical
Date Posted: February/12/2018 at 07:30

I did the whole 308 subsonic thing for a bit.... 16" barrel, but found with the blackout now, not much reason to go load 308 sub rounds that aren't as constant as I liked when shooting subs.  a 30cal projectile fired at the same speeds will yield the same results if the same weights.... the blackout bolt gun does it better than the 308 bolt gun when it comes to subs....IMO

Loading the 308 to 30-06 levels you are going to blow something up, just a matter of when.

"Most folks are about as happy as they make their minds up to be" - Abraham Lincoln

Posted By: jonoMT
Date Posted: February/13/2018 at 16:11
If I hear a loud boom to the east at least I'll know what it was.

Reaction time is a factor...

Posted By: nralifer
Date Posted: February/15/2018 at 20:44
Well, guys don't worry. I have been using a similar load for a long time in my 10 twist 308.  The new rifle we tested was one that a friend of mine and I thought up. He sells actions for ARC. The gun has a Proof Research 8 twist and is 18" long. The load is Jason's 155 gr ICBM, with 50.5 grains of LVR using BR4 primers and Lapua small rifle primer loaded to a 2.880 COL. MV is 2960, and grouped 0.30" at 100 yds.  There was no primer flattening, no extraction problem, no enlargement of the primer pocket and no shiny spots on the brass.  The subsonic load was 12.7 gr Trail Boss using a 188 gr ICBM bullet at 1020 fps. It produced 0.5"groups at 100 yds and with 35MOA elevation one could hit a 10" gong 10/10 shots at 300 yds. on a windy day. The 204 gr ICBM did not shoot with consistent velocities I think because the bullet is long and compressed the TB powder which behaves erratically when compressed.  The gun shows the extreme versatility of the 308 Win with good bullets and a tight twist barrel.  The Leverevolution powder is an excellent one and is the reason we get such velocities with our bullets. The 155 gr ICBM and the 150 gr Bulldozer have a reduced bearing surface and when tested against other 150s on the market have a 50 fps advantage in MV.  That Proof Research barrel is one sweet tube. With a 6" suppressor the subsonic loads are quieter than a pellet gun. Fun stuff!! 


It is hard to fail, but it is worse never to have tried to succeed. TR

Print Page | Close Window