Parent Case Issues

[Ronin6]

[deadcoyote]

Weirdly enough I have both 5.56 and .300 rifles. Really not trying to be that guy but I’ve never read horror stories about this issue on the web r nets. The simple thing I do as a basic safety precaution is I only use plastic magpul mags for 5.56 and aluminum mags for .300.

I don’t think it’s that hard to put the right ammo in the right gun, just figured it’d be a basic visual and tactile reminder.

[Ronin6]

[ar15barrels]

Here is the SAAMI list of unsafe arms/ammo combinations:

https://www.ar15barrels.com/data/unsafe-combinations.pdf

[Ronin6]

Wow, good stuff it should be a Sticky

[ar15barrels]

Wow, good stuff it should be a Sticky

Almost nobody reads the stickies.

[Ronin6]

Then tape it to s stall at Bass Pro’s Mens Head
I never had an idea it was this big, I load 6.5 Grendel and 6 ARC plus 6.8 SPC and 224 Valkyrie so it got me interested in the topic.

Guess I could fire an ARC through a Grendel barrel and have the accuracy of a Brown Bess but would I damage the barrel?

[dfletcher]

Accidentally put a few rounds of 7mm RM through a 300 WM. Accuracy wasn't quite what I had expected.

[divingin]

We’ve all read horror “ stories “ of .300 AAC chambering and firing in a 5.56 Rifle are there others?

Read about it from several sources; seen it once (Blackout in a 223. Didn't end well, though just minor injury to shooter. Can't say the same about the rifle.)

edit: I did not watch this unfold (I should have phrased that better) - I was shooting a few spots down, and was alerted to a problem when the victim started dancing around in pain. Cause was discovered during a post-mortem of the rifle.

On the wrong ammo front, I saw some guys who purchased .300Win Short Mag for their 300 WinMag (which wouldn't chamber) so they proceeded to shoot .30-06 out of the rifle, since that would fit (though it wouldn't extract.) Removed brass looked an anorexic 45-70 case.

I've also seen 223 fired out of 7.62x39 AK. Don't remember any other successful instances of wrong ammo.

[Ronin6]

Could be a problem if someone is “ making “ 6ARC Brass from 6.5 Grendel Brass or .224 Valkyrie from 6.8 SPC Brass / the Brass is still marked after the Parent Case. The smaller bullet should still fly with the accuracy of a scatter gun, I’m assuming without damaging the barrel???? I don’t know if the bigger bullet will chamber into the smaller barrel…………ie Blackout in 5.56 chamber.

I recently started reloading for the Lil Rounds, so the concerns.

[c good]

I've personally put a 5.56 through a Mini 30. My buddy ejected a failure to fire out of his AR and didn't pick up the round. I was next up with my Mini 30. Had a failure to fire due to light primer strike. Held down range until safe to eject. Ejected the round. Reached down and picked it up for a second try.

Thinking it was my 7.62 I unknowingly picked up his .223 and put it into my magazine. Both rounds of ammo were the same type of Wolf Steel ammo. Chambered the round...pullled the trigger....and poof! Bullet exited the barrel....made it about 30 yards before hitting the dirt...puff of smoke from the magazine well and ejection port.

All it did was fire form the steel case and slightly split it. Thus the gas cloud. Pushed out the steel case with a cleaning rod. Took it home and inspected for any signs of damage...and 25 years later I'm still shooting that Mini 30! Lesson learned. Never had that problem again.

[nitroxdiver]

My LGS blew up their full auto fn m249 when a 300 bo round made it into the mix.
Pretty brutal.

[sigstroker]

I do the opposite because magpul makes the .300 specific mags where the subsonics will fit.

[Ronin6]

Anyone ID their different caliber AR Uppers

https://youtu.be/LQJ65TVbTsg

[deadcoyote]

My .300 is a BCM so it has the big .”300 blackout” written on the side.