How many rounds can one pump through a HBAR BM Shorty without hurting it? Is 60 rds in 2 minutes, every 5 minutes, too much? When I do that, it really gets hot, far too hot to touch the barrel or gas block. I can't put it back into it's case for 30 minutes, lest I melt the foam in it.

BYW, It seems that I can rip on my Oly 9mm AR as fast and long as I want and it never gets too hot. Sometimes I go through 4 or 5 32 round mags one right after the other, then load them up again for a few minutes, and start over. I assume this isn't hurting the gun right? It works perfectly everytime.

We went through several hundred rounds of 9mm through a Colt upper and then several hundred rounds more of .223 on a Bushmaster upper in full auto one night and never had any problems.  These guns aren't fragile.  You just have to keep them clean.

God Bless Texas

When I asked this question on the old board I was told something like too hot is when the barrell starts to bend and you shoot a bullet through the side of the barrell.  I reckon you would have a gas tube failure before that happens.  

I've found that it will cool quicker if you stand it upright with the bolt open.

Trust me, you will know when the barrel is too hot. But by then, it will be too late.

Eric The(DasIstSchade)Hun[>]:)]

when the barrel glow gets to be too much, just swap in another upper.

I am no expert but probably the main reason the 9mm doesn't heat up like the .223Rem is because the .223 load has alot more powder and velocity in the case then the 9mm does.  And of course this traslates into heating the barrel.

I have easily dumped multiply 30rnd mags as fast as I could thru my AR and never got it anywhere near hot enough to damage it.  My MAK90 easily gets hotter than the AR and it too has never been hot enough to get damaged...and I got the MAK's barrel almost glowing!!

So in short....don't worry about it[:D]

Sgtar15
[img]http://www.tartarus.net/images/water/frog2.gif[/img]

Sgtar15
[img]http://www.tartarus.net/images/water/frog2.gif[/img]

i can relate to that...I remember doing the same thing.  We had a really cool drill and range officer for our auto night fire.  They let us burn up alot of ammo after the required course was done.  I don't think the old A1 I had could have been hurt...anymore than it was.  

medcop

I had an old 14.5-inch upper that I emptied a 100-rd Beta through in one LONG burst.  The Flash supressor and barrel were glowing RED.  Now, I don't do that with my good uppers but this works out to be 100-rounds in 20 seconds or less!

when the front sight shifts two inches to the right it is to hot

I believe you will find anything and everything you could possibly want to know about rates of fire here:

[url]http://www.biggerhammer.net/manuals/mcrp3-1a/3-01-1/intro.htm[/url]

It's my understanding that alot of info here at Biggerhammer were contributed by folks.

Mike

PS I have not read the entire referenced link, but this is just one of the manuals available, check them out till you get you answer.