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New bullet design!

30 cal.120 GRAIN OPEN TIP (HP) MATCH! Fire formed into .223/5.56.


This is what happens when you have 2 AR15 rifles that look the same, but one is 5.56 and the other is 300 Black out, and you mix them up! Blew the mag out of the lower and shell out of the bottom of the mag. The bullet was about 1-1/2" from the muzzle, and I was able to push it out with a cleaning rod. The upper is junk, Bolt broken, bolt carrier splintered, upper receiver split open I don't know about the lower yet. Other than a small cut on my lower lip I am unhurt! It must have pushed the bullet back into the case, because the bolt closed with no problem.

Yikes, glad you're OK.

I just finished a 300 build. I'm going to order some off those magazine bands that say 300 Blackout!

Yikes, glad you're ok!

How does a .300 BLK cartridge chamber in a .223 gun? Wouldn't the cartridge fail to go into the chamber by quite a bit (3/4"?) because the bullet is too large for the end of the .223 chamber? I'd think that would prevent the gun from firing because the bolt wouldn't be in battery.

BB

BigBlue wrote:How does a .300 BLK cartridge chamber in a .223 gun? Wouldn't the cartridge fail to go into the chamber by quite a bit (3/4"?) because the bullet is too large for the end of the .223 chamber? I'd think that would prevent the gun from firing because the bolt wouldn't be in battery.

BB

The brass gets shortened to make Blackout. They will chamber, there have been quite a few kabooms.

Jackpine Savage wrote:The brass gets shortened to make Blackout. They will chamber, there have been quite a few kabooms.

Weird. Sure looks to me like the width of the bullet on the .300 would make it too wide to fully chamber in a .223 chamber. Right where the .223 necks down the .300 is much wider. I guess that must not be the case, but it doesn't seem like it would be possible.

BigBlue wrote:

Jackpine Savage wrote:The brass gets shortened to make Blackout. They will chamber, there have been quite a few kabooms.

Weird. Sure looks to me like the width of the bullet on the .300 would make it too wide to fully chamber in a .223 chamber. Right where the .223 necks down the .300 is much wider. I guess that must not be the case, but it doesn't seem like it would be possible.

When the Bolt slams shut it pushes the bullet deeper into the case. this was a factory load (Remington) with not much cantalure on the bullet and little to no crimp.

So don't shoot ammo in a gun made to shoot a different cartridge? Got it!

BuckKlier wrote:When the Bolt slams shut it pushes the bullet deeper into the case. this was a factory load (Remington) with not much cantalure on the bullet and little to no crimp.

Ah...

Known issue with <150gr bullets. I painted the bottom of all my 300BLK mags orange, or have upgraded to the 300BLK dedicated mags from Magpul.

photogpat wrote:Known issue with <150gr bullets. I painted the bottom of all my 300BLK mags orange, or have upgraded to the 300BLK dedicated mags from Magpul.

Ditto, marked rounds and white mags. Sub sonics white mags with blue band.

I use completely different mags for my 300blk and rubber bands on each one to label super or sub-sonic. Of all places, I got the bands from a seller on Amazon, and they look like wrist bands. I probably could've saved money and just used regular rubber bands, but these look cooler and I thought being able to label each mag was worth it.

I'm using Lancer 300blk mags which are supposed to handle the bigger sub-sonic bullet noses better than standard mags. I have not noticed a difference, but again was an excuse to do something that would help me tell them apart from my other AR mags.

Oops

Erud wrote:So don't shoot ammo in a gun made to shoot a different cartridge? Got it!

Minor technicalities

photogpat wrote:Known issue with <150gr bullets. I painted the bottom of all my 300BLK mags orange, or have upgraded to the 300BLK dedicated mags from Magpul.

Yep! I painted an 2" OD green stripe on the bottom of the my 300BLK Magpuls ('cuz tactical) to avoid loading 300BLK into my .223. Still scary to consider it happening. My Daniel Defense 300BLK looks alot different than my .223, but still...