308 subsonic load components

[ZincChloride]

Hi, I'm trying to find out a different way to do case prep and would like to hear your feedback on what you've found to work.
So far I've been very successful drilling out the flash hole to 1/8" and using winchester large rifle magnum primers with trail boss of course. The brass I've used so far has been just old winchester and hornady brass and my best groups have been steadily around 12" diameter.
I've been thinking about using nosler brass and maybe just a regular fed. 210 primer or cci br2 primer.
Anyone have any experience with different preps?
Thanks and I appreciate everyone's reply.

 

[bohem]

Re: 308 subsonic load components

12" groups or is there a typo in there? Are they stable or are you getting keyholing?

I'm shooting groups in the (barely) sub-inch range with PRVI bullets and mixed stamp brass.


I don't open the flash holes up or do anything special for brass prep. I recently was given about 100 pcs. of CBC (Magtech) 1x's brass and I started using it for subsonics. I used the 178 Amax's and it shoots about 1/2 MOA from a 1:11.27tw Rock Creek 20"

What are the groups shaped like? (vertical stringing or just a shotgun pattern)
What distance (I'm assuming 100yd)
What twist rate
What bullet
How does the rifle shoot with regular match ammo?

 

[ZincChloride]

Re: 308 subsonic load components

No typos, I'm shooting 208 amax in a 1:10" twist 24" barrel with 11.6 gr. of trail boss, winchester LR Mag. primers with the flash hole at 1/8" drilled. This is also at 300 yards.
There are no keyholes, and the pattern is oval shaped if any. I've been thinking that the mag primers might be the problem. it shoots sub moa with match ammo all day long. I think I'm going to try my nosler brass with fed. 210's and work up loads to that. idk... what do you think?

 

[bohem]

Re: 308 subsonic load components

At 300yd makes a lot more sense, the minor variations in velocity have a much bigger effect at the low MV's and longer distances.

I would try some brass that doesn't have the flash hole opened up, and some non-magnum primers. I have not put my loads above on paper at 300yd, but I have a 6" steel plate that is an easy 50 MOA dial and then I can clank it over and over again.