New .300 BLK Load

Well, we’ve been playing with the .300 BLK for a few months now and decided it was time to try out a new load.  Initially we were using the recommended load data from AAC; but, I have to admit that those 220gr Sierra bullets were getting a bit expensive @ ~$.40 apiece. icon smile New .300 BLK Load

Instead, we decided to try the 208gr A-Max bullets from Hornady since they’re just a bit lighter and quite a bit less expensive.  On top of that, we can buy them at Cabela’s and I always seem to have Cabela’s bucks saved up – which makes them quite a bit cheaper…

Anyway, for our first attempt, we used the following recipe:

  • 208gr Hornady A-Max bullet seated @ 2.12″ OAL
  • 11.0 grains of A1680 powder
  • Remington 7.5 primer
This first batch was extremely consistent, with high & low velocities being only a few fps apart out of our 12.5″ .300 BLK upper.  As a result, the accuracy was excellent!
Unfortunately, the average velocity ended up being 1134 fps – so I need to bump it down just a bit to stay subsonic.  I suspect 10.9 grains will be the magic number; although, we may end up having to go to 10.8.
I also noticed that, without the suppressor, the weapon only locked back on empty about 50% of the time – and had trouble picking up a new round a couple of times.  This particular lower has a hydraulic buffer installed to slow the bolt down – and I think it’s actually working against us in this case.  The next time out I’ll try an H2 buffer (or even an H buffer) to see if it fixes the issue.  As a side note, it was close enough to cycling that it worked perfectly with all of the suppressor models we tried.
Since we were supersonic anyway (although barely), we went ahead and shot through all of the initial rounds and spent some time with the following suppressors:
  • SWR Octane 9 HD – This is probably one of the best values currently on the 9mm pistol suppressor market.  It performed very well with the .300 BLK, as it has with 9mm – and it’s also small & light-weight compared to the 7.62mm alternatives.
  • Bowers CAC9 – The CAC9 is a subgun can and seemed just a bit long on our .300 BLK.  It would have fit perfectly, however, on the 8″ upper.
  • YHM Stainless Phantom – Interestingly enough, our Phantom must have gotten some oil in it at some point.  It was smoking like crazy, so that’s pretty much all I noticed – and we just didn’t have enough ammo to spend a lot of time on it before rinsing it out. icon smile New .300 BLK Load
  • AAC Cyclone – As usual, the Cyclone performed very well.  The Cyclone is a great value among 7.62mm suppressors.
  • Thunder Beast 30P-1 – The Thunder Beast suppressors always amaze me!  The 30P-1 is light-weight, extremely quiet, and very accurate.  That’s a hard to beat combination!

Overall, most of these suppressors performed well.  We didn’t do any sound metering because the ammo was supersonic, but we did have a lot of fun!

Stay tuned for another update once we get this recipe honed for our gun.  At that point, we’ll also get some sound metering results so we can really compare these different suppressors.

I can’t wait to get this back to the range again!

Posted June 11, 2012