Wise reloading teachers, please show me the way!

I'm at the end of my rope on loading sub-sonic 300 aac blackout for suppressed use in a bolt gun. I started with H110 but then switched to Red Dot. I've tried multiple loads and I can stabilize the bullet and get subsonic velocities. Mainly with 208 grain hornandy a-max's (although I've played with 220gr sierra match kings too).

I would be happy with anything less than 1 inch groups at 50 yards from a rest given the situation I plan on using these for. And I can't get these. I've tried every two tenths of a grain from 5.8 to 6.2 of red dot getting velocities between 930fps on the low end up to 1115fps on the high end. The most consistent load seemed to be to be 6.2gr but I can only get 1.2 inch groups at 50 yards off a bench.

So I'm starting to wonder if it is the rifle. It is a savage but it was rebarreled by the prior owner for the 300 blk out. I've figured out it is a 1:8 twist and the rifling looks to be traditional (not ratchet). I bought it used and don't have any other history.

So do I play with this more or start over and buy the ruger american ranch and start over?

http://www.ruger.com/products/americanRifleRanch/specSheets/6968.html

What kind of optics are you using?

The 300 blk out can be very sensitive with the powder you choose. IMO, H110 is too slow burning and Red Dot is way too fast. I'd recommend doing a little research on different powders that will work best in a bolt gun. There is a sweet spot to be had.

Agree with Chad, though I have not loaded for the 300BO I have loaded for some others and there are other powders that will most likely work better. Trail boss comes to mind as does Universal and 5744, but do your research and work up loads carefully. The 1:8 twist should work great for sub loads.

Trail boss is one that will not work in the blk out. It works great in bottle necked cases, but not straight walled cases.

Thanks for the correction Chad, I have used it in the 308 but since I have no 300 BO and data not at my present location did not remember that.

Have you tried buying some commercial ammo and running them through?

Yes, UMC was awful, about 20% went super sonic, accuracy and velocities all over the place. My intention for this rifle all along was to reload for it.

Maybe there is an issue with the rifle then.

Did you accuracy test with supersonic ammo?

Maybe have a gunsmith check the dimensions of chamber, leade, and bore?

These were my first results from a DTech AR in Blackout.. This is shooting a 1-4X scope Both Hyper and Subs functioned fine.

I have had good results with AA1680 and 208 amax in my bolt and AR.

I'm working on a load with lil gun right now. Have you tried to adjust seating depth or a light crimp

I'm going to work up some loads using HS-6 (because it is what I have) and it has a burn rate between H-110 and Red dot. Not giving up yet! I have tried different seating depths. Supersonic with H110 & 110gr V-max bullets I was able to get less than 1 MOA with this rifle.

Thanks!