300 BLK -- in a 5.56 Rifle

Be careful Dev.

Snag-dabit, that dang Doc won't let me post links or images until 7 days after I've joined.

h t t p s/ / : w w w.facebook.com/JCWeaponry/photos/a.191088200956321.46019.123855004346308/626635837401553/?type=1&theater (Remove extra spaces)  Thanks, mate!

The link I WANTED to show was the impressive results of firing a 300BLK in a 5.56 gun. In the cutaway, the .30 cal projectile was about five times longer then when it started, and it got approximately half-way down the AR-15 pistol-length barrel before the cartridge web blew out and dumped hot gas into the mag and the receiver. Shooter was unharmed - but the gun was obviously significantly damaged.

I appreciate the advantages of using the same magazines and bolt between the 5.56 and the 300BLK. However, this is a standing invite to Capt. Murphy. I'm hearing more and more of this type of accident. Additional care is warranted; maybe something needs to be devised to help guard against this error.

to paste a hyperlink (URL) just chop off the h t t p / / : w w w part and this will stop the script on this site recognising it as a link.

sthwestvictoria wrote:to paste a hyperlink (URL) just chop off the h t t p / / : w w w part and this will stop the script on this site recognising it as a link.

No, Doc has a restriction on posting links until you have been around for some time. I tried it (correctly) and it wouldn't let me, but perhaps now I'm done my "time" and can do links.

You know, you posted another article on just this issue previously. I recollect reading it.

I understand the basic issue. But in some ways it's about like having an ND - you have to be responsible. I am not sure I would necessarily allow someone else to load my mags for me, unless he was seriously trustworthy. I got that lesson way back when I offered a guy to shoot my CZ 75 - and he managed to put the round in backwards and then drop the slide on it - took some work to get it unjammed. No more letting just anyone load stuff.

The .300 BLK is enough different that you ought to notice it. It is big and fat appearing, not like a 5.56. I guess you can make the same comparisons with .357 Sig vs 9mm vs .40, but I don't think the .40 would chamber in a .357 Sig barrel (I ought to try it once, just for grins. Not to shoot, but to see if it'd fit.)

Doc made endure a 8 day waiting period before I could post links. Kinda like Cali's 10 day wait for firearms.

And as effective.   

Charlie Foxtrot wrote:Doc made endure a 8 day waiting period before I could post links.  Kinda like Cali's 10 day wait for firearms.  

And as effective.      

+1!

If I posted that before - Me bad.

Still thinking about a 300BLK, especially if I get a can when in MO. As such, I'm watching this issue with interest. I'm looking to somehow make it idiot proof, because -- frankly, I'm an idiot. The words "I'll be more careful" are often Chekhov's Guns for many of my more entertaining disasters.

I'm thinking now that 300BLK ammo should be strictly segregated from the 5.56. Loading 300BLK should be a discrete action: You get the different colored bag containing 300BLK, along with the 300BLK rifle. You move them to the bench which has been cleaned of everything 5.56, load the mags, then rock on. Importantly, the 300BLK does not get out of control, misplaced, or mixed up. Several of the 300 in 5.56 errors have been made by very experienced shooters. The pros are in agreement: someday, somedood is goin' get kilt.

That is a fantastic photograph CF. That is an expensive and quick way to ruin a barrel.
I do like the way it has been turned into a teaching moment however.

Yeah, and I desperately want to learn from their mistakes -- not mine.

Look how nicely the 300BLK fits in the 5.56 chamber: the .30 cal bullet fits right into the 5.56's shoulder.  I'm thinking they should rename the cartridge the .300 Murphy.    

Still, the more I learn about this cartridge, the more it looks like a very nice self-defense option, especially in an AR Pistol with a suppressor.

If you enjoy reloading, .300 blk will give you endless hours of experimentation and fun. I have 3 different firearms chambered in .300 blk and enjoy them very much. I have loaded bullets as light as 110 gr jacketed all the way up to 245 gr hard cast. The other week, I tested some subsonic 110 gr bunny fart loads with a suppressor--very very quiet. I also tested some supersonic 125 gr hornady sst's and some 150 gr hornady fmjbt all the way out to 600 yards on a steel plate. The hold over was significant, but I was able to consistently hit the steel plate. If you want a rifle cartridge to play or practice with (which doesn't take much powder), 300 blk may be your cartridge.

Damn good to see you again, Corny!

Dang, that's for certain. You guys are gonna talk me into a 300 BLK AR yet.

The UPS guy just delivered my Wilson Combat barrel and flash suppressor! Went downstairs. Biggest time waste was finding all my AR tools. But once I got it all in one place at one time, it was a piece of cake. I used a VTOR upper, YHM diamond 9" free-floating hand-guard, Wilson NP3-coated BCG, some charging handle (don't recollect which) and a YHM low profile gas block and gas tube. Took all of maybe 40 minutes. The one glitch is that Wilson sent me a flash hider for 6.8 SPC, not .30 cal. I called them and they will get back to me on what they will do to fix that situation.

I used one of those Geissele bars to hold the upper. What a dream! It is flat on one end to fit in the vice, and ribbed to fit into the AR locking ribs. You can spin the upper to where ever you want by pulling it off a bit, turning, then pushing it back onto the lock. I also use the Geissele pin starting tool for the gas block. One neat aspect of the Geissele tools is that they come in neat package. It's a plastic tube that unwinds to open. It can obviously be reused for storage. I had never seen anything like that.

Devereaux wrote:The UPS guy just delivered my Wilson Combat barrel and flash suppressor! Went downstairs. Biggest time waste was finding all my AR tools. But once I got it all in one place at one time, it was a piece of cake. I used a VTOR upper, YHM diamond 9" free-floating hand-guard, Wilson NP3-coated BCG, some charging handle (don't recollect which) and a YHM low profile gas block and gas tube. Took all of maybe 40 minutes. The one glitch is that Wilson sent me a flash hider for 6.8 SPC, not .30 cal. I called them and they will get back to me on what they will do to fix that situation.

I used one of those Geissele bars to hold the upper. What a dream! It is flat on one end to fit in the vice, and ribbed to fit into the AR locking ribs. You can spin the upper to where ever you want by pulling it off a bit, turning, then pushing it back onto the lock. I also use the Geissele pin starting tool for the gas block. One neat aspect of the Geissele tools is that they come in neat package. It's a plastic tube that unwinds to open. It can obviously be reused for storage. I had never seen anything like that.

I will NEED to see pics!

Minds infinitely superior to mine have been working on the 300 BLK in 5.56 problem.

Keeping track of ammunition in a multi-caliber environment

Still not CF proof, but getting there. I favor using a polycarbonate mag for 300 BLK ammo. They look, feel and sound very different. They're also very spendy, which would alert my highly developed Scot Cheap Baaaaastard sense.  

HT: Oleg Volk