308 and 300BLK subs!

[Sivispacemparabellum022]

ok so 308 is a savage 20" shoots great with Lapua subsonic 200gr.
300 BLK is a 10.5" AR haven't shot anything through it yet.

I bought Hornady A-Tip 230gr and I finally found trailboss.

does anyone have any pet loads for either, obviously I know I need to work up my own. I'm just trying to find a safe starting point that people have tested already. Any information is great thank you

 

[kindabitey]

Subsonics - All Calibers

Insert ALL data as other loads.

www.snipershide.com

 

[1moaoff]

A tips for 300 BO.... ?

 

[Sivispacemparabellum022]

Well I got them for the 308 but figured maybe they could be awesome in the blackout too. I’m new to the blackout so I kinda feeling around in the dark a little

 

[Shootin Stuff]

Are you hunting or target shooting?

Hornady makes a 190gr hollowpoint that will get full expansion at subsonic velocities for hunting, but most of the heavier hollowpoints are designed to work at typical .308win speeds (or faster) and can have unreliable expansion out of a subsonic 300blk.

For target shooting subs I am playing around with a bunch of 200gr+ projectiles, but would not expect these to perform on game.

Trailboss produces extremely low velocities (make sure to NOT compress a load with it) and with 230’s you are likely to be leaving A LOT of velocity on the table even for subs, so run it past a chrono and make sure it’s not TOO slow.

 

[Sivispacemparabellum022]

98% of the time I will be Target shooting. I did test some velocities today.

Lapua Brass
CCI BR primers
230gr A-Tips
Trailboss powder

None were compressed loads. And seated at 2.245 Ogive (3.245“ minus 1” for the Hornady comparator clamp)

13gr - 1140fps
12.5gr - 1104fps
12gr - 1092fps
11.5gr - 1067fps
11.4gr - 1036fps
11.3gr - 1025fps
11gr - 1011fps

Tomorrow I think I will settle on 11.3gr and load a few to see some groupings and adjust from there.

 

[Shootin Stuff]

Nice, those trailboss loads are faster than I thought they were going to be.

I use TB in the 45-70 for light plinking loads, but your results have got me thinking I’ll need to try it in the blk as well!

 

[Sivispacemparabellum022]

ok so I was doing all this through my savage 10 .308. 20” stock barrel 1-10 twist. Scratch all of the data! The rounds do not stabilize, thank god I was doing all of this before I tried them through my suppressor. 60yrds. Back to the drawing board.

 

[Sivispacemparabellum022]

I checked my twist calculator on my computer, I guess I could have saved myself some time and effort. But the specific gravity with all of my variables calculated in is .93! I need to have 1.5 or better to be very stable.