I recently took my AR out and shot about 120 rds through it to try out some new mags I got. I put all the rounds through the gun in a couple minutes rapid fire. It was a little chilly not too bad but the barell started to smoke. not from inside the barell but from outside and under the handguards. Is this pretty normal or should i be concearned. The last time i shot it it got hot but not as hot and about the same load was put on it. If it matters I have a Oly Arms Car-97 in 5.56 and i was shooting South African surplus battle pack ammo. any info would be appreciated

I believe you are wittnessing oil burning off the barrel. It is likely that some oil was on the barrel under the handguards, as well as the exposed portion of the barrel. This could explain why the smoke appeared to be coming from there and not elsewhere. I noticed this the first time I put some rounds in quick sucsession through my Bushmaster. Smoke came from under the handguards and from around the sight base.

Others will be able to speak with more authority on this matter, however I believe the oil will burn off well before you are at risk of damaging your barrel.

anyone else have any info or is the first reply pretty much the answer

Yup, it's the oil burning off. I get it after a coupla mags of FA through my '16. As long as the barrel isn't glowing or your handguards melting (I've done both), you're prolly OK.

But don't forget to reoil the outside of the barrel when you're done shooting ... after the oil/lubricant cooks off, the metal is vulnerable to rust.

I've fired M16's till the barrel got so hot you could only handle with a glove on.  Big fear was a round capping off in the chamber but I'm writing this so It didn't happen to me.  Since then the rule of thumb I've used is if you can still pick it up with bare hands then fire away.  Large calibers will smoke off the oil alot faster typically less than 20 rounds.  Guns smoke and doesn't worry me. Heat does though.

Thanks guys i just wanted to make sure i wasnt ruining something because barells arnt that cheap