I went to the range today and shot my Bushmaster A2 HBAR today for the first time.  Man, it was way more fun than I was expecting, but I have a question;  My barrel got really hot and I was worried about doing serious damage to it.  I didn't rapid fire at all.  I put 200 rounds through it in a couple of hours.(The gun is used, so it has already been broken in)  What is a good rule of thumb to avoid barrel damage when shooting a couple hundred rounds?  How hot is too hot to continue shooting?  

Thanks,
LUAVUL

You can shoot it pretty much as fast as you can pull the trigger and never worry. Unless you have full auto don't worry to much. The heavier the barrel the longer you can sustain fire without damage.

Quoted: You can shoot it pretty much as fast as you can pull the trigger and never worry. Unless you have full auto don't worry to much. The heavier the barrel the longer you can sustain fire without damage.

Unless you're going to make it a bench gun, I wouldn't worry too much.  I'm assuming that since its a bushmaster that its got a chrome lined barrel, which will save your throat in heavy hot fire.  

Enjoy the gun, don't worry too much about a hot barrel though.  I wouldn't have worried about putting all 200 of those rounds through the barrel in 10 minutes, no matter a couple hours!

Well, if you get a RDIAS and more than 5 or so Beta C-Mags, then start to worry.  Other than that, just don't burn yourself on that barrel!

Thanks guys.  I feel better now.  Yes it does have a chrome lined barrel.  I am hooked on AR's now.  I am ready for another one to keep this one company.  We'll see.

Thanks again,
Luavul

it as almost impossible to 'burn' a HBAR firing it in semi auto mode, either way semi or full and when really really hot it will start cooking off rounds (making rounds to auto ignitiate(sp?) when chambered because of the temperature ).....and if after your rifle start cooking off you still keep pulling the trigger you deserve to get a 'burned' barrel . Don't worry about it, and have fun with yer new toy.
HUNTER FROM ARGENTINA
OUT.

Luavul,

I believe that miniman hit the nail... the concern isn't bbl wear but more accurately throat/chamber erosion.

Throat erosion is exacerbated through heat and pressure. Normally when you see substantial accuracy loss it's a worn chamber.

If you're shooting 300-500 rounds in a session (hour or 2) you will see significant wear after about 20K rounds (give or take). Chrome helps!

Most guys won't shoot this way or that type of volume.

Hunter mentioned cook offs. I've never seen a cook off from semi auto fire but I have seen cases swell or bind in the chamber. i.e. I've seen extractors strip through the rim when the shooter cleared his rifle after a hard live fire session. This has happened when the shooter ran 3-400 rounds in a short period (1/2 hour) and then kept a live round in the chamber for a period of time. It seems that the heat caused the round to swell in the chamber, causing the extractor to rip through the rim when he jacked the bolt back to clear.  

Just make sure that you visually clear the chamber!

Cook offs are a definite threat in Machine Guns. Just ask anyone whose fired a MG 34....cyclic rate around 1000 per minute!! These babies don't get hot, they glow!

My .02 is to shoot the living piss out of that gun! Train hard and have fun. Start every range session with a 10 round slow fire at 100 yards. When groups become unacceptable then swap out the bbl.

Easy day.