testtest

Why Your .300 BLK Won’t Work…

jumpinjoe

Professional
Yes, it will chamber, it will lock, and it will go boom

Well yeh, I would think so! When it locks up it's simply pushing the 30cal bullet deeper into that small capacity case (where btw, there is little or no more room). That my friends is what causes extreme high pressure and a big, fat chunk of lead that simply won't fit down through that tiny, little hole out front. And typically things that go Boom right after that!

Please tell me that was a typo and meant to say a .223 or 5.56 will chamber in a 300blk.
 

jumpinjoe

Professional
I was in a shoot once many years ago right beside a guy (on his right side) who unintentionally loaded a 30/06 round into .270 Win rifle. Well, not surprisingly it did the same thing as a 300blk in a .223 chamber will do. It pushed that big ol' fat 30 cal bullet down into the case just enough, and when he pulled that trigger it went Boom!

Don't remember what kind of rifle it was, and at the time didn't care. But I can tell you my shooting was over for the rest of that day.
 

HansGruber

Hellcat
I was in a shoot once many years ago right beside a guy (on his right side) who unintentionally loaded a 30/06 round into .270 Win rifle. Well, not surprisingly it did the same thing as a 300blk in a .223 chamber will do. It pushed that big ol' fat 30 cal bullet down into the case just enough, and when he pulled that trigger it went Boom!

Don't remember what kind of rifle it was, and at the time didn't care. But I can tell you my shooting was over for the rest of that day.

On that note—

When surplus WW2 bolt actions were the rage, it was often asked which was strongest—the Mauser, Springfield, or Enfield (Nagant's not being in the mix, as they really hadn’t come over in any numbers...Soviets really didn’t want to arm those running dog capitalists, you know...).

Turns out it was none of them; it was the Arisaka.

This was discovered by (iirc) Col. Townsend Whelen, when he was writing for the NRA and was asked why a Arisaka kicked so badly.

Turns out they were shooting 7.7 Arisaka in a 6.5 Arisaka. The bullet was being swaged down, but going downrange just fine, no damage to the rifle. Townsend tried to blow one up...I think he was unable to, or was finally able to after using a truly ludicrous amount of the wrong powder.

But, to circle back to .300BO....yes, marking mags is a good idea.
 
I was in a shoot once many years ago right beside a guy (on his right side) who unintentionally loaded a 30/06 round into .270 Win rifle. Well, not surprisingly it did the same thing as a 300blk in a .223 chamber will do. It pushed that big ol' fat 30 cal bullet down into the case just enough, and when he pulled that trigger it went Boom!

Don't remember what kind of rifle it was, and at the time didn't care. But I can tell you my shooting was over for the rest of that day.
He was using the correct rounds for the correct upper assemblies.
 

jumpinjoe

Professional
He was using the correct rounds for the correct upper assemblies.
I'm confused ...... it was said he chambered a 300blk in a .223 chamber. How is that using the correct upper assembly? Admittedly I don't know a whole lot about those ugly, black, military looking, assault rifles (;)), but a chamber is a chamber is a chamber isn't it.

Don/t mean to sound stupid but I'd really like to understand this. :unsure::confused:
 

BET7

Hellcat
Founding Member
I'm confused ...... it was said he chambered a 300blk in a .223 chamber. How is that using the correct upper assembly? Admittedly I don't know a whole lot about those ugly, black, military looking, assault rifles (;)), but a chamber is a chamber is a chamber isn't it.

Don/t mean to sound stupid but I'd really like to understand this. :unsure::confused:
JJ, I think the point of his post was to prevent accidentally loading 300 BO into a .223 AR. Since .223/5.56 and 300 BO can utilize the same magazine, you could accidentally mix them up and attempt to fire the wrong cartridge in the wrong barrel. Hence he partially paints his Mags that contain 300 BO in FDE color so he can see that when he inserts them into the lower receiver. Thus it's an added precaution that he knows the upper better be chambered in 300 BO. At least that's how I took his post.
 

jumpinjoe

Professional
My bad !!!!! I misread a post earlier and thought it said someone had actually done that. I think I've got it sorted out now.
(y)(y)(y) Thanks BET7 for clarifying.
 
You all didn't understand. A .300 subsonic ammunition out of a .300 barrel with a full auto lower. It fired 3 rounds then jamed. That is what my brother in law told me.
 
JJ, I think the point of his post was to prevent accidentally loading 300 BO into a .223 AR. Since .223/5.56 and 300 BO can utilize the same magazine, you could accidentally mix them up and attempt to fire the wrong cartridge in the wrong barrel. Hence he partially paints his Mags that contain 300 BO in FDE color so he can see that when he inserts them into the lower receiver. Thus it's an added precaution that he knows the upper better be chambered in 300 BO. At least that's how I took his post.
I would suggest marking the upper assembly, as you can visually see the difference in a. 223 round and a .300 round. I have both rifles, and both rounds. I had to read the markings on the barrels to know which rifle it was. As far as marking magazines. I use different color mags for different types of ammunition.
 

jumpinjoe

Professional
Even though the .300BO will load and sometimes/most times feed from a .223/5.56 mag, it is a far better bet to have and use a mag made expressly for the .300. I can't tell you exactly the difference, but I'm pretty sure the difference is in how the mag is actually manufactured.
 
Top