Warning! - 300AAC round with Barnes TAC-TX 110gr, will lock and load in FN SCAR 16s 5.56mm

[MoovinTarget]

Just a word of WARNING from a ticked off owner of damaged FN SCAR 16s...

Several of us ventured out to the competition range for some practice this past weekend. We had several rifles being swapped about for comparison sake.
One of the group grabbed a standard AR-15 mag loaded with a few rounds of 300AAC blackout rounds and locked it into a SCAR 16s 5.56mm.
He actually chambered and fired two rounds before the weapon failed. The first scored and X-ring and the second scored an 8. It was the sound that caught my attention.

Luckily no one was injured. The ejector blew backward and vaporized the ejector spring and ejector pin. The cam pin orifice was deformed in the bolt. The chamber is also out of round at the throat.
This appears to be the extent of the damage. The barrel did not swell nor rupture, at least as it appears to the naked eye.

I just wanted to ring the bell since this could easily happen to someone else as more 300 Blackouts are fired in the company of AR-15 5.56mm shooters. Remember these two rifles use the same magazine, same brass prior to trim and sizing, and very similar chamber specs minus the actual bore. It will lock, load and fire.

The round was a 110gr Barnes TAC-TX with the trim and COAL within spec. I wish I could have found the copper javelin that squeezed out the end of the barrel.

 

[MarkCO]

That is probably the 10th I have heard of (although the first for a SCAR). Not uncommon with people who are not paying attention to their gear.

 

[Veer_G]

My son did it to us at the range and stuck a 5.45x39 into a 7.62x39 magazine. Interesting, to say the least. Gotta watch. His comment? "They all look alike."

 

[gimpy]

Wile not as scary as this, I saw .40 fire from a 1911.

 

[QuickNDirty]

Wile not as scary as this, I saw .40 fire from a 1911.

I've seen that on more than one occasion. Watch your Tulammo 45ACP. Sometimes it has 40 in it, and it will fit in the mag and fire. Won't cycle the action.

 

[HD1911]

I've seen 9mm fired thru .40 twice now

 

[rjacobs]

The guys on 300BLKTalk like to "use different colored magazines" or "only use xxxx type of magazine" or "put colorful bands on the magazines" or "insert other whacky thing here" and guys like me that say "look at the fucking ammo" get ridiculed. I believe one guy over there who was the loudest proponent of only using a certain type or color of magazine had a kaboom because HE LOADED THE WRONG AMMO INTO HIS SPECIAL MAG. To reliant on the "special mag" or whatever and STILL not paying attention to what you are doing.

That SCAR is one tough gun to withstand a 30cal bullet going down a 22 bore even once. All the AR's I have seen that have done this have blown on the first round.

And lets not forget the person who sent a 300BLK round through an M42k suppressor. That was an interesting picture AAC posted.

 

[pizzamanny]

Not the first or the last.

 

[MarkCO]

I've seen 9mm fired thru .40 twice now

Yes, but a .223 through a BO, a 9mm through a .40, a .243 through a .308, etc. are all sub caliber. Yep, you will pop a case and may do some minor damage, but for the most part, there is very little damage and the pressure is not even close to normal. When you pop a .30 cal into a .223 case and put it in a .223 chamber, it makes a pretty decent seal and since the case dimensions are similar, you will go WAY PAST the normal pressure.

This is a rather unique condition and one that people should be very careful about.

 

[HD1911]

Yes, but a .223 through a BO, a 9mm through a .40, a .243 through a .308, etc. are all sub caliber. Yep, you will pop a case and may do some minor damage, but for the most part, there is very little damage and the pressure is not even close to normal. When you pop a .30 cal into a .223 case and put it in a .223 chamber, it makes a pretty decent seal and since the case dimensions are similar, you will go WAY PAST the normal pressure.

This is a rather unique condition and one that people should be very careful about.

I'm well aware... don't read too much into my post.

 

[MarkCO]

I'm well aware... don't read too much into my post.

I won't. But I also realize we have all levels of persons on here with associated differing levels of knowledge and or skill.

 

[HD1911]

I won't. But I also realize we have all levels of persons on here with associated differing levels of knowledge and or skill.

No Worries

 

[Ledzep]

So the entire bullet made it out of the barrel or is there still lead/copper in the chamber?

Impressive.

eta: just dawned on me that it would only be copper.

 

[hlee]

So... How did the 300 blackout make it into the chamber to fire? Spent brass from my AR-15 has an diameter of .253" at the mouth of the case. Saami specs for the 300 blackout round show a diameter of .334" at the same location. Is the force of loading in a SCAR-16 sufficient to set the bullet back into the case and resize the case neck? Was this an out of battery detonation? My knowledge of the 300 BO is apparently very slim...

 

[MarkCO]

The dimension you are measuring is at a different location in the OAL on each cartridge. If you were to take the "shadow" of a .223, for most loads, the .300 BO will be either equal to or inside that shadow.

 

[hlee]

Thanks MarkCo! I had lost sight of oal considerations thinking about neck diameter.

 

[grayghost]

I won't. But I also realize we have all levels of persons on here with associated differing levels of knowledge and or skill.

People get forgetful all the time check out explosion at Manate

 

[grayghost]

I won't. But I also realize we have all levels of persons on here with associated differing levels of knowledge and or skill.

People get forgetful all the time check out explosion at Manatee

 

[FNARSHOOTER]

30 cal bullet down a 22 bore once hard to swallow twice and hit the target both times I call B.S. The case /primer ect would lose its shit and lock it down the first time and the bullet would never make it out the barrel. I highly doubt you could DRIVE a barnes or any other 30 caliber bullet thru even a 8" barrel with a hammer and punch!! let alone a 16" barrel. Pictures and sworn notarized statements or its B.S.

 

[Forgetful Coyote]

Im kinda having a hard time seeing this too. Its not impossible but that would have to be the most indestructible rifle ever built, far stronger than any bolt action. And I just dont see that happening. Id mainly like to see what recovered bullets look like.

 

[rrflyer]

It's not an uncommon thing nowadays

 

[John D.]

Im kinda having a hard time seeing this too. Its not impossible but that would have to be the most indestructible rifle ever built, far stronger than any bolt action. And I just dont see that happening. Id mainly like to see what recovered bullets look like.

I'm half in/half out on this one.

Half in: I know that certain .300BLK rounds will chamber and fire in a 5.56 gun despite early AAC protests to the contrary. Below is a 5.56 DD upper where the owner got his ammo mixed up and chambered a .300 round. The driving of the bullet back into the case upon chambering not only allowed the gun to lock and fire but also raised the chamber pressure through the roof as the pics show. The side of the receiver was blown out and the bolt was destroyed.

Half out: In this lower the bullet was stuck in the barrel, causing a considerable bulge. The SCAR 16 must be stronger than any portable rifle known to man to survive that. I can't see a single bullet leaving the barrel let alone two but hey you never know.

 

[velillen]

The guys on 300BLKTalk like to "use different colored magazines" or "only use xxxx type of magazine" or "put colorful bands on the magazines" or "insert other whacky thing here" and guys like me that say "look at the fucking ammo" get ridiculed. I believe one guy over there who was the loudest proponent of only using a certain type or color of magazine had a kaboom because HE LOADED THE WRONG AMMO INTO HIS SPECIAL MAG. To reliant on the "special mag" or whatever and STILL not paying attention to what you are doing.

Im one of the "use special mag" crowd. But take it a bit further. My 300blk uppers all have FDE rails so i can easily tell them apart. 556 is black. Mag wise i tend ot use just a 10 round blk pmag but when i use 30 rounders its a fde for 300blk and black for 556.

But more importantly to myself i follow a rule of 1 type of ammo out at a time. I dont care if i have 3 guns out the only ammo that comes out is the one being shot. In the case two are being shot i only allow obvious different calibers such as 223 and 45-70. I also dont let anyone else touch my ammo either though

 

[anon]

Having been the Barnes bullet should actually be to their benefit. Aren't those bullets a homogenous alloy that has been softened so as to deform uniformly in the barrel? The extrusion ratio (R) is less than 2. The shoulder in the 223 chamber is at 23 or so degrees. Looking for pressures to extrude copper, on the web, I find that it may be as high as 100K psi. Remember those bullets are not hard copper. Anyhow, yeah, pics or it didn't happen. It would be interesting to hear from a metallurgist who actually does extrusions.

 

[rjacobs]

Yea I dont know what the hardness level of the black tips are, but I would bet they are potentially one of the softest of any of the all copper projectiles since they will expand down to 1300FPS. Got to do something to make them expand that slow and being soft would be one way to do it.

Im pretty sure though that I have seen pics of a 5.56 AR15 that kaboomed with a factory Barnes 110g Vortex black tip round went through it.

 

[50APIT]

There have been a few of these posted on ar15.com over that last few years, the bullet, 110gr v-max, on this one almost made it through a 16" barrel:

A different AR-15 where the owner said the bullet, 125gr SMK, did clear the barrel:

 

[Strykervet]

30 cal bullet down a 22 bore once hard to swallow twice and hit the target both times I call B.S. The case /primer ect would lose its shit and lock it down the first time and the bullet would never make it out the barrel. I highly doubt you could DRIVE a barnes or any other 30 caliber bullet thru even a 8" barrel with a hammer and punch!! let alone a 16" barrel. Pictures and sworn notarized statements or its B.S.

You do know how we swage bullets, right? This would a violent form of that. I'm surprised it worked and I didn't know you could chamber BLK in a 5.56 --but I don't try shit like that.

Sworn statements and shit, I'm sick of this, who the fuck does this? I was in the army and have a DD214 but I'll be goddamn if I show it to anyone on the internet to prove it. Take it with a grain of salt, believe, don't believe, whatever. It's the internet. Or mythbust it with your own sworn statements, in triplicate and notarized and get back to me.

Got a Glock 17 that one guy shot a squib load in, fired another in behind and it pushed it out, then another squib (which got hammered out). That pistol still works great to this day. Low pressure with or without blockage is just as bad as overpressure, btw. So what would have been way more catastrophic would be for that bullet to lodge.

Overpressure is one thing, a spike in pressure is completely different. So if it can push the bullet down the bore by swaging it (and I believe there is enough pressure to do so) then it CAN happen.

 

[FNARSHOOTER]

Sworn statement was used as a joke. A lie can be written as well as spoken. When you swage it is a force applied only for the length of the projectile/swage die. Not 16" and applied by a compound force not burning powder. So you are comparing apples to oranges. I do not want or need to see your DD214 but would bet your MOS had nothing to do with Physics. If you think any auto loading weapon with a 22 cal bore can fire/cycle and fire again a 30 cal bullet and then fail. While both super swaged bullets hit the target GOD BLESS YOU .FYI I think your Glock story was BS also but thats the beauty of being me I get to choose what to think.