I was considering the same the other day on different bounds, and the only things I could come up with as improvements were a different mounting method for the stock tube (no big-arse threads, interference pins, I’m mentioned this before), a directly-attached “post” operating handle instead of the one-way top mount it has now (though, would really slow the lefties down), and modular/replaceable drop-in fire control assemblies, like Chip Mc makes but containing the FA sear or 3-shot cam.

Since I’ve never seen some of the above, I guess that’s two patent-disqualifying posts of the day…

I don’t think the consequences would be as bad as you think. The bolt would be locked into it during firing, and the tube stopping rotation… actually, and I’d have to look at one real closely, in battery it’d be hard to impossible to launch the barrel, some friction point in the loading/bolt return phase would have to shove it off.

At that point, with the barrel going/gone, the front of the reciever is open. I don’t think you’d have enough instant pressure do get frags or gas anywhere but out the front and out the ejection port. Then again, the cartridge would be hanging halfway out the front of the reciever… but then AGAIN, that also means it has no cross-axis reference, the ejector would toss it off to the side before the firing pin could strike it. THEN again, if the ejector’s not working right if could be held to the bolt face tight enough to fire… but THEN AGAIN (heh) the gun would have tied up before the failure point.

Look at the photo, the threads on the reciever are noticeable flattened. I bet the barrel nut was corroded (as above) and/or was out of spec and overtightened at some point, predamaging the threads to where they stripped later.

It’d take some force still to strip those threads off… I’d LOVE to know at exactly what point in training it broke loose. You can’t apply side force to the barrel nut because the chamber extension is tight in the receiver… you can’t push on it for the same reason. It’s have to be pulled, or have some action applied that yanked the barrel straight off.

Do they still use bullet traps or blanks in simulated fire training, or is it all IR now?

The upper probably got rebarreled many times. The upper as well as the lower receiver should last forever. The problem was over torqued and most likely the armorer didn’t grease the threads to prevent corrosion.

These weapons are not safe queen. They are used and abused regularly by kids. Not only that these weapons are suppose to last forever. They are repair or retrofit at the armory level. There are some first generation A1 lowers and uppers that are still being use by our military.

Weird question I’ve had for a long time: Anyone make a steel upper for the AR? I know that there’s basically zero point for having one made out of steel rather than aluminum but I just thought it’d be neat.

And since there is often such rousing discussion re: weapon failures on this blog, what kinds of horrible consequences could there have been if the rifle had come apart this way during firing?

I’m thinking unsupported chamber explosion and a wild shot.

The only logical reason I ever heard for the military’s adoption of three-round burst was that it would slightly decrease the rate of fire when using the newer 30 round magazines. Apparently, the M-16A1 had a tendency to launch their barrels when sustained FA was used in training, with total disregard for the amount of heat that was going into the receiver. There’s no amount of training that can counter a reckless disregard for safety, and firing a rifle until the barrel is cherry-red is something I’ve seen and heard about people doing on more than one occasion. Respect your guns people!

“troop, you know what you and an aluminum can have in common? you can both be recycled!”….arghhhhh!

Didn’t quite understand this part… Rephrase?