My 300 Blkout rifle build

[94ranger]

Looks great!

[Guest SMZRU275]

So I shot this finally a few weeks ago. The issue I ran into was the first batch of formed brass had shoulder issues in relation to the point on the case where it was formed. I had changed my process during and the 2nd batch was fine. Due to the case issues the bolt wouldn't lock and jammed it about 1/2 out of position also making it a bitch to get the round extracted. I had loaded more from the first batch of formed brass then 2nd so I only ran about 50rounds through it that day. Got the red dot just about right on, and didnt even get to touch the irons.

I've got through and measured the neck/shoulder and ended up throwing out most of that first batch of formed brass, all the 2nd batch fell into proper spec. So I've got some 147gr to load and more brass to form.

[Dolomite_supafly]

Seems like you could tighten the body sizing die and fix the first batch. Sounds like the first batch were not completely sized. I have had the exact same problem with 223 brass in my AR. I went back and checked my die and it wasn't contacting the shell holder.

I really do need to build a bolt gun in this caliber.

Dolomite

[Guest SMZRU275]

Reloading .223 was a breeze compared to doing the 300blkout .Getting into loading this caliber and also forming the brass has been hard but very rewarding. It's made me get more detailed with my work, and learn more about reloading then just read a data sheet, do the motions, and go shoot.

I think it's overall making me a better reloader, and making my rounds come out better in the long run.

[Dolomite_supafly]

I have done a few different odd calibered builds. And those had ZERO reloading data to begin with. I stuck bullets in the bore and ruined primer pockets during the testing. In the end I was very happy with the results.

Dolomite

[mikegideon]

And, I thought the .458 SOCOM was frustrating. There's almost no pressure tested data out there. The brass manufacturer (Starline) is excellent, and there's a guage available to test the finished product. It's a piece of barrel blank with chamber and lands.

Is there a source for off the shelf brass for the blackout?

[Dolomite_supafly]

And, I thought the .458 SOCOM was frustrating. There's almost no pressure tested data out there. The brass manufacturer (Starline) is excellent, and there's a guage available to test the finished product. It's a piece of barrel blank with chamber and lands.

Is there a source for off the shelf brass for the blackout?

I would assume so becaue there is factory loaded ammo, both supersonic and subsonic.

Dolomite

[Guest SMZRU275]

Remington is only source for factory brass. TONS of places and people are selling reformed LC 5.56 brass.

Easiest way is with a Dillon 1200 and a whisper die. Trims and reforms in one stroke.

[Guest SMZRU275]

First video up of it. Wasn't really concerned on the accuracy of this mag, just that they were going to cycle without issue after the adjustments in the reforming.

http://www.youtube.com/watch?v=cuRgnuBhh3s