300Blackout Journey Page 3
May 18, 2014 Update
Having discovered a reliable supersonic load that will be my favorite/go to load, I decided to start work on developing a subsonic round. As my results will show this is much more difficult. I would end up purchasing lead 245gr 300Blackout Thumpers from Missouri Bullet Company.
Today Darrell and I had great results with the Remington Micro 7 with Yankee Hill Suppressor and 11.3gr of Accurate 1680 and 220gr Sierra Match Kings which shot under 1 inch at 50 Yards and quieter then Remington Factory 220gr Subsonics. What I had really hoped for were for some of my test Missouri Bullet Company bullets and load would work, this would prove to be frustrating, yet still alot of fun.
On this day we would not have much luck getting this round to function 100% in our AR’s. I think the loads were a little long for the PMAGS at a COAL of 2.139,
though we did find that with a new GI mag with Orange follower Darrell recently purchased for bench shooting worked much better.
I think this hunk of lead is going to be utilized only in the bolt action and could be a good reason for me to get a Remington 700 chambered for 300 Blackout :). Sounds like a good reason to get a bolt action to me.
Today I would also have some test loads of my favorite plinker supersonic rounds. I have previously tested these rounds and knew what it was capable of. What I would be testing is an RCBS Chargemaster against my 20 Year old RCBS Uniflow. My RCBS Chargemaster throws would also be weighed on a RCBS 5.0.5 Beam scale the same used for the uniflow. Since these loads are loaded with H110 which meters great I really didn’t expect to find much difference. What I really wanted the Chargemaster for was throwing stick powder which will be tested on another day.
| Rifle | Barrel Length | Gas Tube Length | Ammunition – Powder-Manual | COAL | Bullet Weight/Bullet Type | Velocity FPS | Average Velocity FPS | ES | SD | Group Size | Weather Conditions | Bolt Lock Back |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rock River Lower Wilson Barrel 300BlackOut | 16′ 1/8 Twist | Carbine | Reload H110-15.5gr Uniflow | 2.100 | 150gr Hornady FMJ | 1862 | 1861 | 44 | 15 | Testing to see which measure gives me lower ES and SD | 63 Degrees | Y |
| Low 1836 | ||||||||||||
| Hi 1880 | ||||||||||||
| 1864 | ||||||||||||
| 1864 | ||||||||||||
| Rock River Lower Wilson Barrel 300BlackOut | 16′ 1/8 Twist | Carbine | Reload H110-15.5gr RCBS Chargemaster | 2.100 | 150gr Hornady FMJ | 1880 | 1881 | 13 | 5 | Testing to see which measure gives me lower ES and SD | 63 Degrees | Y |
| 1885 | ||||||||||||
| Hi 1888 | ||||||||||||
| Low 1875 | ||||||||||||
| 1880 | ||||||||||||