Thoughts On .300 Blackout

Spose I'm a fan. My favorite light 30-cal has been Speer's 125tnt. They shoot great with a variety of powders, and are one of the cheapest bulk 30 caliber projectiles available. If you don't like spending .30-.60 cents a bullet for the heaviest 200+gr 30-cals, I'd shop around for 2nds or blemished batches that turn up. Last year for a brief time midway had 240gr matchking 2nds @ .21 cents a bullet.

There's an overwhelming plethora of suitable powders but H110 & A1680 are 2 of the more popular ones for 300blk. H110 will produce top velocities with the lightest bullets. 1680 is great for heavy sub loads or supersonic loads with heavier 150+ grain pills.

Handloading section 300blktalk.com
http://www.300blktalk.com/forum/viewforum.php?f=141

I can do repeated full auto mag dumps with my home cast powder coated 150gr bullets and H110, and other powders. It's very economical until the happy switch is activated.

FYI even with very soft boolits the AR devours them without hesitation or undue filth or fouling. Powder coating rules!

Important note on loading 300bo for AR rifles: mark the point on your chosen bullet that measures .250" in diameter, then seat until that line is riding the bump in the magazine. Otherwise your mags won't be happy and neither will you. This gem escaped me for a while when I was staring out loading for it and it was a frustration.

I use the 110vmax and the 125tnt in my 300rar, as well as the 245mbc bullets. Before that i ran all three thru my AR upper. Powder for 110s and 125s is H110 or lilgun. I used h110,4198, and 4227 but never got the 245s to cycle as subs. Not that it mattered too much as i ran them mostly super.

My RAR shoots the same loads, but i run ths 245s over 6grns of 231, as cycling isnt an issue.

My favorite load is using Hornady 110 V-Max bullets with H110 powder for around 2370 fps in a 16" carbine. Next for plinking is M80 147 FMJ's also with H110 powder at about 1950 fps. I also load Nosler 125 BT's just in case I'd want to hunt and approx. 2155 fps. All in reformed LC once fired military brass and RP 7 1/2 primers. Working on sub-sonic loads with suppressor for Hornady 208 A-Max and 220 gr. Sierra's with AA1680 powder. Haven't tested but once with 208 A-Max and don't get my BLK to fully cycle and I think my loads are going supersonic?? Will continue in the spring. The Hornady 150 FMJ's are a very popular bullet in 300 BLK.

My AAC Blackout Model 7 really likes 150 grainers behind H110. It really comes into its own with these. I tried some 120 softpoints, but they just didn't work as well. I should try some lighter grain bullets, but I bought a 2K case of 150 grain Hornady FMJ's last year and until I need some more, I don't see the need. H110 for 300blk is a keeper.

How do you like it? What do you use it for? Any thoughts are welcome.

Click to expand...

I like mine, it's a neat looking 8.5" barrel inside a rifle length tube so the 762SD suppressor telescopes back inside the tube.

I played with subsonic for awhile until it just seemed like a waste of money vs my 9mm AR that costs a lot less to play and is better suppressed.

I use mostly the lighter supers with H110 powder but that too is mostly for play, it really doesn't do anything better than various other uppers I have can do. I guess it's more of a jack of all trades round vs a master at any one job.

Ok, I'll Bite as well... I shoot a lot of 300AAC/Blkout, it is a Blast out of a 10 1/2" Suppressed barrel. I cast my own .30 cal bullets, they weigh in at 228gr - 229gr, I set them on CCI Small Rifle Primers and 10.0 gr IMR 4227, and .010 off the Lands. I get 999 fps at 5 Yards, Extreme Spread 50fps, Standard Deviation 14fps, all rounds fully cycle, No FTE, No Stovepipes. I have intentions of working this load up to right at 1000fps, but am wary it will effect the extreme spread..

Good Luck, Be Safe, Be Strong...

Not to hijack, but I am getting started in Blackout myself, helping a friend. The data I found uses Small MAGNUM Rifle primers. Is there going to be any detriment running regular Small Rifle primers with Lil'gun and light (110-130gr) bullets?

I've used 155 Hornady xtp and 205 Hornady ahead of 15.5 and 10 grains of 4227 respectively. Small rifle primers. I like both loads.

badkarmamib said:

Is there going to be any detriment running regular Small Rifle primers with Lil'gun and light (110-130gr) bullets?

Click to expand...

Not at all. You may see a standard SR primer show signs of pressure before the magnums do when you get to the top end of your loads - but typically the magnum primers are more suited for semi-autos simply because they have a thicker cup, and are less prone to slam-fires (personally I've loaded thousands of CCI400s in ARs and never had an issue). With some brands the amount of priming compound is the same between their standard and 'magnum' offerings - only variable is the cup thickness. Of course that's not the case across the board - some brands of 'magnum' SR primers do have more priming compound than their standard offerings, and with certain powders you'll achieve better ignition/burn & velocity by using a magnum primer.

I can remember reading a thread a few years back where a fella kept the load the same, and experienced a spread of like 80fps with a handful of different branded primers being the only variable - this was in a 300blk.

Ive used CCI standards and mags in the same loads at "book" max and have seen no difference. I didnt chrono them so i cant say as to effect on velocity.

I've found federal standards soft compared to.winchester or cci. Haven't used them in the 300 but loads thwt are fine with cci and win in my 223 will squish a federal pretty flat.

This all comes back to reworking up loads as you chqnge components, and while i dont drop back to starting I'll usually drop a grain ot two then come back up.

I've had good luck with Accura 120 grain plated projectiles in my 8.5" SBR. Details here:

https://www.thehighroad.org/index.php?threads/accura-30-caliber-projectiles.814111/

Jmorris, how do like the 762SD? I have been looking at AAC suppressors among others, although that's a ways off yet.

Click to expand...

It's way overkill and heavy for the 300 blk but I already had it and an extra QD mount so I used it. Good can though.