Reloading 300 BLK

[theswan_33]

Hey guys,

I am trying to get started on reloading some subsonic target BLK. I am tossing around the Hornady A-MAX and Sierra Matchking. I need a powder! I have seen H110, A1680 and A5744 used commonly. Anybody ever tried IMR8208?

 

[Nimaro]

Great question, I'm curious as well

 

[458 SOCOM]

I have used H110

Curious combo the OP is proposing.

 

[Okie4570]

All I've used so far is H110, but haven't loaded any subsonics. Reading this below, might the 8208 be too slow?

January, 2010
For Immediate Release
Shawnee Mission Kansas- IMR® Legendary Powders introduces a new super powder, IMR 8208 XBR.IMR 8208 XBR where no target is too small is a remarkablyadvanced technology propellant perfected for the greatest match, varmint and sniper rounds known today---223 Remington/ 5.56mm, 308 Win./7.62 mm, 6mm PPC, 204 Ruger, 6mm BR, 22-250 Remington and similar calibers.
This short grain extruded rifle powder exhibits a previously unheard of consistency with virtually no change in velocity at temperatures ranging from -40 degrees F to 165+ degrees F. Uniformity from shot to shot translates into tack driving accuracy and this powder has passed the test:
Currently loaded in premium factory sniper type ammunition
Leading competitive bench rest shooter Mr. Lou Murdica won numerous matches with it in 2009, starting with Heavy Varmint Grand Aggregate at the Cactus Classic
August 2009 Mr. Jim Carmichel won the International Benchrest Shooters Association’s 40th Group National Championships, Heavy Varmint Grand Aggregate. Because temperature conditions change, bench rest shooters vary charge weights during a day’s competition. What is significant here is that Jim shot the exact same load of IMR 8208 XBR both days to win the event
IMR 8208 XBR are available in 1lb canisters and 8lb kegs at dealers everywhere. For more information or complete data visit imrpowder.com and the Reloading Data Center, see the 2010 Annual Manual, phone IMR at 913-362-9455 or write to 6231 Robinson, Shawnee Mission, KS 66202.

 

[theswan_33]

Pardon my ignorance but what in the passage would make you think it was too slow?

 

[Okie4570]

Pardon my ignorance but what in the passage would make you think it was too slow?

It may be perfectly fine, I was just looking at the cartridges listed above and was thinking that a bullet weight of 3x-3.5x that of what would normally be shot out of a shortened .223 case would require something faster. Can't find any info on the combo you're asking about..............but it's a quest now!

 

[theswan_33]

I couldn't find anything either. That's why I was asking. Always looking to improve. Never be satisfied. I do see what you are saying about the bullet weights though. Definitely don't want a bullet lodged in the barrel.

 

[Shadowrider]

I'd be shocked if 8208 would work for subsonic loads. It's burn rate is right with IMR-4895 which is the gold standard for 7.62 and 30.06 ball loads for full rifle length barrels.
H110/296 is what I read is the **** for SBR'd subsonic .300BO loads. That's where I'd start. For carbine or rifle length full velocity loads with lighter bullets it might work, but I'd think that IMR-3031 would be a better choice. I did try it in a 18" barreled 3gun rifle and it shot only decent groups and was crazy consistent in sorted brass, but I couldn't get the velocity I wanted and went back to BLC2.

Note: I don't really know, I'm just spitballing here. I've yet to build my black out gun but I have read a bunch about it.

 

[theswan_33]

Alright fellows. Here's another question. Everything that I am reading is saying to use a powder with a fast burn rate, such as powders used for magnum pistol rounds, and to use give or take 9 grains of it. I have not reloaded any yet but I would assume that this would leave a great amount of air space between the powder and the bullet and would also lead to the assumption that the powder would not burn consistently in each round because it's orientation in the brass COULD be different each time. I have read where you could use a wad of sorts but that seems iffy to me.

So here it is. If you made a compressed load with a slower burning powder (IMR8208) would that generate the pressure needed? In theory I would believe so! Plus it would create a uniform burn every time! SOMEONE SAVE ME FROM MYSELF BEFORE I BLOW MYSELF UP! LOL!

Just kidding, on a serious not what do you all think?

 

[theswan_33]

Hey SOCOM, was your H110 load supersonic or subsonic? How were the groups?