300 Blackout vs 5.56 chamber - Question

[Eric300]

I'm posting this question on the M&P 15 thread because I figured I'd get a better response from 'AR' folks then I would if I post it on the 'Lounge', or, elsewhere. Mods, if you feel that this isn't he most appropriate place, please feel free to move it.

Since the 300BO is a .30 cal. projectile and is fitted into a 'necked up' 5.56/.223 casing, and, the same mags and BCG (bolt carrier group) can be used for both the 5.56/.223 & 300 BO, the question that I am going to ask, and, want a general consensus on is this;

'Is it possible for an AR-15, regardless of who manufacturer is, that is chambered for 5.56/.223, both chamber, AND fire, a 300 BO round?'

I'm interested to see what replies I get on this one.

[colt_saa]

Originally Posted by Eric300

I'm posting this question on the M&P 15 thread because I figured I'd get a better response from 'AR' folks then I would if I post it on the 'Lounge', or, elsewhere. Mods, if you feel that this isn't he most appropriate place, please feel free to move it.

Since the 300BO is a .30 cal. projectile and is fitted into a 'necked up' 5.56/.223 casing, and, the same mags and BCG (bolt carrier group) can be used for both the 5.56/.223 & 300 BO, the question that I am going to ask, and, want a general consensus on is this;

'Is it possible for an AR-15, regardless of who manufacturer is, that is chambered for 5.56/.223, both chamber, AND fire, a 300 BO round?'

I'm interested to see what replies I get on this one.

I presume you are kidding

You want to try a round of .300 BO in a .223 rifle?

You will never push something measuring .30" into a .22" hole

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Now the opposite could occur.

A round of .223 could chamber in a 300 BO rifle and fire.

The projectile will just rattle down the barrel and not do much more than that once you set off the primer

[mckenney99]

Absolutely. Results can be "startling". I never take both calibers to the range at the same time. All my 300 Blackout magazines have 300Blk bands on them and my various 300 Blackout guns have several prominent identifiers on them to indicate 300 Blackout. A loaded 300 Blackout cartridge is short enough that IT WILL chamber in a 223/5.56 chamber and fire if the trigger is pulled.

[CZU]

I have a friend whose brother wasn't paying attention and did just that. AR15=DESTROYED. He was lucky though.

[Eric300]

I am not kidding at all.

Originally Posted by colt_saa

I presume you are kidding

You want to try a round of .300 BO in a .223 rifle?

Of course not. You are interpreting this question wrong. Stand-by and you will see.

You will never push something measuring .30" into a .22" hole

Don't be too sure about that....

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Now the opposite could occur.

A round of .223 could chamber in a 300 BO rifle and fire.

The projectile will just rattle down the barrel and not do much more than that once you set off the primer

[Eric300]

Originally Posted by CZU

I have a friend whose brother wasn't paying attention and did just that. AR15=DESTROYED. He was lucky though.

Ahhhhh, now we're getting somewhere.

[Eric300]

Originally Posted by mckenney99

Absolutely. Results can be "startling". I never take both calibers to the range at the same time. All my 300 Blackout magazines have 300Blk bands on them and my various 300 Blackout guns have several prominent identifiers on them to indicate 300 Blackout. A loaded 300 Blackout cartridge is short enough that IT WILL chamber in a 223/5.56 chamber and fire if the trigger is pulled.

You are a wise man!

[SMSgt]

Short answer--yes. But you will not like the results. Don't try it.

[SMSgt]

Originally Posted by colt_saa

A round of .223 could chamber in a 300 BO rifle and fire.

The projectile will just rattle down the barrel and not do much more than that once you set off the primer

But will the bolt close, seeing as the .223/5.56 shoulder length is significantly longer than the .300 BO? Methinks no.

[Eric300]

Ok, apparently, this isn't going as I expected. So, before this thread goes sideways, here's what I was getting at......A little while ago, a buddy of mine who is relatively new to AR's, calls me and says that his AR blew up while shooting it. First I asked if he was OK, and other than some minor shrapnel in the face and chest, no serious injuries. Since I knew he had 2 ARs, a 5.56 and a 300BO, I asked him which one. He said it was the 5.56 (no need to mention brand since it's irrelevant to this discussion). He only lives about 5 miles away so I grab my AR 'medical bag' and drive to his house to investigate. After looking at what was left of his AR I start grilling him. Long story short (I know, too late), he had both his 300BO and 5.56 out and was shooting both behind his house. He inadvertently loaded a few rounds of 300BO into his mag and inserted it into his 5.56. The rest is history. I ended up performing a post mortem autopsy on his deceased rifle. The 30 cal bullet made it all the way to the gas port before stopping. I had to hammer it out with a cleaning rod. It extruded to almost 2" long.

The moral of this story is; KNOW what the heck you're doing when handling/shooting firearms!

Enjoy the photos.














Case


Bullet

[Sistema1927]

That is the reason why:

1) All of my 300 AAC magazines are well marked with bands, and
2) I never take 5.56 and 300 AAC to the range at the same time.

[scooter123]

All of my .223 magazines are BLACK and all of my 300 BLK magazines are DESERT TAN. In addition I do not take both calibers to the range and the dust cover on the 300 BLK is marked as such in WHITE.

[rtquig]

Your friend was very lucky. Thanks for the pictures, it helps to see what damage was done.

[mckenney99]

I am so paranoid of something like this happening that the rifles cases for my different rifle caliber AR's are different colors. Black cases 223/556, Tan cases 300 Blackout, Green cases 6.8 spc. My Galati International 6 pocket magazine carry pouches are color coded with the calibers/cases. Overkill? Look at the pictures above and reconsider.

[andy52]

Interesting post I've really never tried to chamber a .223 in my .300 BL.
I'll give it a try tomorrow to see if they will chamber....but definitely won't see if they fire…...

[Sistema1927]

Originally Posted by andy52

Interesting post I've really never tried to chamber a .223 in my .300 BL.
I'll give it a try tomorrow to see if they will chamber....but definitely won't see if they fire…...

The danger comes from chambering a 300 AAC in a 5.56/.223 gun. A 5.56/.223 fired in a 300 AAC won't be pretty, but a 300 AAC fired in a 5.56/.223 gun will be disastrous.

[Eric300]

Originally Posted by Sistema1927

The danger comes from chambering a 300 AAC in a 5.56/.223 gun. A 5.56/.223 fired in a 300 AAC won't be pretty, but a 300 AAC fired in a 5.56/.223 gun will be disastrous.

What? The damage done in those pics wasn't 'disastrous' enough for you? What's your idea of disastrous?
? lol

I guess the take-away from all of this would be to not load anything that starts with the #3 into a chamber that's starts with the #5. But, those pics are from a 300BO thru a 5.56mm.

[Eric300]

Originally Posted by rtquig

Your friend was very lucky. Thanks for the pictures, it helps to see what damage was done.

You can never have too many safety reminders!

[Rivoak]

A 300blk round theoretically should not chamber, but it can get pushed down in cartridge by the BCG enough for the AR firing pin to hit a primer. If you pull the trigger, it may go Kaboom.

The more appropriate question is can a 30 caliber bullet go down a 22 caliber barrel, and the clear answer is NO. Many have tried. None have succeeded.

I put a band of yellow electrical tape around the base of every magazine loaded with 300BLK and NEVER mix .223 and .300 Blk magazines in the same bag. I also do not take both calibers to the range on the same trip.

Don’t know if anybody has ever been killed by loading a blackout round in a .223 rifle, and don’t care to find out either.


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[Abflyboy]

I was on the firing line 4 lanes away with a guy who did exactly that ... fired a .300BO cartridge in a 5.56 barreled rifle.

He was virtually unscathed and I was picking tiny bits of his rifle out of my head and arm for 6 months.

[Eric300]

Originally Posted by Abflyboy

I was on the firing line 4 lanes away with a guy who did exactly that ... fired a .300BO cartridge in a 5.56 barreled rifle.

He was virtually unscathed and I was picking tiny bits of his rifle out of my head and arm for 6 months.

That had to pucker the ol' spinchtor.

[Eric300]

//////////////

Originally Posted by Rivoak

A 300blk round theoretically should not chamber, but it can get pushed down in cartridge by the BCG enough for the AR firing pin to hit a primer. If you pull the trigger, it may go Kaboom.

Good explanation.

The more appropriate question is can a 30 caliber bullet go down a 22 caliber barrel, and the clear answer is NO. Many have tried. None have succeeded.

This is 100% incorrect and I beg to differ. Read the entire OP. I had to get the 30 cal. round out of the barrel with a metal rod and hammer. The round made it up to the gas port. It was almost "1.5" long. A physical anomaly if you ask me. I think I have a pic of it. Stand-by...….

Found it! This is the 30 cal. round that I beat out of the barrel. You can even see the rifling marks in it. I have no idea what brand of ammo he was using, or, the type of bullet. Looked like a typical FMJ. (I added it to the orig. pics)




I put a band of yellow electrical tape around the base of every magazine loaded with 300BLK and NEVER mix .223 and .300 Blk magazines in the same bag. I also do not take both calibers to the range on the same trip.

Don’t know if anybody has ever been killed by loading a blackout round in a .223 rifle, and don’t care to find out either.


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[Sistema1927]

Originally Posted by Eric300

What? The damage done in those pics wasn't 'disastrous' enough for you? What's your idea of disastrous?
? lol

I guess the take-away from all of this would be to not load anything that starts with the #3 into a chamber that's starts with the #5. But, those pics are from a 300BO thru a 5.56mm.

I don't know what your argument with me is. Go back and read what I wrote.

[LostintheOzone]

That was kind of troll question. Hope you got some enjoyment out of it. Doesn't fit this forum real well.

[Eric300]

Originally Posted by LostintheOzone

That was kind of troll question. Hope you got some enjoyment out of it. Doesn't fit this forum real well.

Not really a troll question. Just to get folks involved in the discussion, a safety reminder, and perhaps some knowledge.

If you don't like it, keep it to yourself, and/or don't respond, and move on down the road.

I do get enjoyment out of helping others and possibly help keeping them safe when handling firearms and related equipment.

If this wasn't the proper forum, I did ask the mods to move it if they seem fit. Apparently, they don't, sooo…..

Now go play somewhere else since you obviously have nothing intelligent or constructive to add.

[Eric300]

Originally Posted by Sistema1927

I don't know what your argument with me is. Go back and read what I wrote.

Sorry if it sounded argumentative. Didn't intended it that way, hence all the smiley faces. Sorry if you took it that way.

[Rivoak]

“I done ‘’splaining sumtin to anybody can’t understand my ‘splanation.” Charles Darwin

“Let em sort it out” Charles Darwin

“Hold my beer” Goober


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[LostintheOzone]

Originally Posted by Eric300

Not really a troll question. Just to get folks involved in the discussion, a safety reminder, and perhaps some knowledge.

If you don't like it, keep it to yourself, and/or don't respond, and move on down the road.

I do get enjoyment out of helping others and possibly help keeping them safe when handling firearms and related equipment.

If this wasn't the proper forum, I did ask the mods to move it if they seem fit. Apparently, they don't, sooo…..

Now go play somewhere else since you obviously have nothing intelligent or constructive to add.

I do have something intelligent to add. Anyone who has the proper firearms training should already know what the hazards are of chambering the wrong ammo. Just because your friend doesn't know or is careless doesn't necessarily mean anyone here needs to get trolled into a basic safety lesson.

I see you're pretty new here. We aren't a bunch of newbies around firearms so we don't especially need a 101 level introduction class on how not to blow yourself up.

You might have better luck getting yourself a Youtube channel and helping all the unfortunate newbies that don't have a clue and don't want to spend a dime to get trained up.

Sorry, I just don't like clickbait.

[Eric300]

Originally Posted by LostintheOzone

I do have something intelligent to add. Anyone who has the proper firearms training should already know what the hazards are of chambering the wrong ammo. Just because your friend doesn't know or is careless doesn't necessarily mean anyone here needs to get trolled into a basic safety lesson.

I see you're pretty new here. We aren't a bunch of newbies around firearms so we don't especially need a 101 level introduction class on how not to blow yourself up.

You might have better luck getting yourself a Youtube channel and helping all the unfortunate newbies that don't have a clue and don't want to spend a dime to get trained up.

Sorry, I just don't like clickbait.

Opinions vary. Sorry you feel that way.

[SMSgt]

Meh. A little JB Weld and some bore cleaner and it will be good to go.

[Steve912]

Originally Posted by Rivoak

“I done ‘’splaining sumtin to anybody can’t understand my ‘splanation.” Charles Darwin

“Let em sort it out” Charles Darwin

“Hold my beer” Goober


Sent from my iPhone using Tapatalk

The dust cover inscription is ironic, yet
appropriate.

[AManWearingAHat]

Yes it will chamber and fire, which makes it a very dangerous combination. I urge anyone I know who shoots both calibers and keeps both on hand to color code their magazines. See my photos.

Fortunately when AR's fail from this they tend to fail in a "safe" fashion that does little to no damage to the shooter (except maybe his underpants). However, that is no excuse for making this mistake.

[Eric300]

Originally Posted by AManWearingAHat

Yes it will chamber and fire, which makes it a very dangerous combination. I urge anyone I know who shoots both calibers and keeps both on hand to color code their magazines. See my photos.

Fortunately when AR's fail from this they tend to fail in a "safe" fashion that does little to no damage to the shooter (except maybe his underpants). However, that is no excuse for making this mistake.

Well said and nice pics for a visual example.

[ARVOL]

Originally Posted by Eric300

Sorry if it sounded argumentative. Didn't intended it that way, hence all the smiley faces. Sorry if you took it that way.

You’re still missing Sistema1927’s point... reread his original post again...

[Eric300]

Originally Posted by ARVOL

You’re still missing Sistema1927’s point... reread his original post again...

Ok, I've re-read it a bunch of times but don't see what I'm missing here? A 300ACC would be more 'disastrous' than a 300BO in a 5.56? I'm just not getting it. Help a brother out....

[ARVOL]

Originally Posted by Eric300

Ok, I've re-read it a bunch of times but don't see what I'm missing here? A 300ACC would be more 'disastrous' than a 300BO in a 5.56? I'm just not getting it. Help a brother out....

Now I know you’re just messing around with everyone!

AAC... by the way. (small hint)

[Sistema1927]

Hint: 300 AAC = 300 Blackout.

In fact, the SAAMI name for the round in question is 300 BLK, and the C.I.P. name is 300 AAC Blackout. Same round, exact same round. (And to confuse things further, the exact same cartridge is also known as the .300 Whisper.)

[ARVOL]

Originally Posted by Sistema1927

Hint: 300 AAC = 300 Blackout.

In fact, the SAAMI name for the round in question is 300 BLK, and the C.I.P. name is 300 AAC Blackout. Same round, exact same round. (And to confuse things further, the exact same cartridge is also known as the .300 Whisper.)

I thought the .300 Whisper was slightly different than the .300 AAC Blackout??

[Eric300]

Originally Posted by Sistema1927

Hint: 300 AAC = 300 Blackout.

In fact, the SAAMI name for the round in question is 300 BLK, and the C.I.P. name is 300 AAC Blackout. Same round, exact same round. (And to confuse things further, the exact same cartridge is also known as the .300 Whisper.)

Ya know, I was just laying here on the couch and it hit me! Duh. I'm reading it and reading it and it never occurred to me. Sometimes the obvious just escapes me somehow. lol I refer to it a BO so often that the AAC just blew right by me. I really wasn't messing around. Just had a minor brain fart. Getting old ya know. Ok, you win, my bad. 7.62x35mm

[Sistema1927]

Originally Posted by ARVOL

I thought the .300 Whisper was slightly different than the .300 AAC Blackout??

.300 Whisper to 300 AAC Blackout is same as .223 Remington to 5.56mmx45.

Not enough difference of consequence. Maybe someone will start marketing "300 Wylde" chambered guns.

[Recusant]

I've found this to be a very informative post. I own several AR15s and an AR10 in .308. No way to confuse ammo or mags. However, since I don't own or shoot the 300 Blackout I've never even gave a thought to the problem presented in this thread. Now that I have seen the light I'm going to make sure that a fellow who brings his AR15 in 300 Blackout to deer hunt with us keeps his ammo and mags straight

[Eric300]

Originally Posted by Recusant

I've found this to be a very informative post. I own several AR15s and an AR10 in .308. No way to confuse ammo or mags. However, since I don't own or shoot the 300 Blackout I've never even gave a thought to the problem presented in this thread. Now that I have seen the light I'm going to make sure that a fellow who brings his AR15 in 300 Blackout to deer hunt with us keeps his ammo and mags straight

Mission accomplished!!