This question is about barrel temperature. I am wondering if I am babying my barrel or if I am on the right track. Normally I fire 20 rounds and if the barrel is too hot to hold comfortably in my hand I 'll let it cool off for awhile. Is this the right procedure to prolong the life and accuracy of my barrel?

Maybe I am being too easy on it and can let it get a lot hotter without worry. I know many other guys at the range go through a lot more rounds than I do in the same amount of time. hinking.gif

Thanks…

I have a chrome lined barrel.  I've had my gas tube glowing at a night shoot bump firing it.  This is still much cooler than what a full auto M4 does for temperature so I'm sure you're quite safe.  At long distances you could probably tell a difference in groups and POI from different barrel temps but up close it would be close to the same.  

Temperture doesn't really hurt barrels, bad cleaning practices (makes bad crowns and muzzle wear) and throat erosion usually does.

I am wondering if I am babying my barrel or if I am on the right track. Normally I fire 20 rounds and if the barrel is too hot to hold comfortably in my hand I 'll let it cool off for awhile. Is this the right procedure to prolong the life and accuracy of my barrel?

Well, you definitely won't wear out the barrel like that The AR15 barrels can withstand quite a bit of flat out abuse and still hold up for several thousands of rounds. You can get your barrel much hotter than that with no problems though. Until you start to see the CLP smoke off the barrel, you aren't even in the realm where heat is something I would think about and you can regularly smoke the CLP off the barrel and still see the barrel life exceed 30,000-40,000 rounds in semi.

If you are talking short-term use, the gas tube will blow out before the barrel does (though cook-offs can happen long before that). If you are talking long-term use, even an abused non-chrome-lined barrel should be good for around 10,000 rounds before throat erosion leads to reduced accuracy.

Temperture doesn't really hurt barrels, bad cleaning practices (makes bad crowns and muzzle wear) and throat erosion usually does.

Temperature contributes quite a bit to throat erosion through a process known as heat checking. Basically, the metal around the chamber develops tiny microscopic cracks from repeated exposure to heat - kind of like a pool of mud drying in the sun. The metal then begins to flake off and throat erosion happens faster.

This is eventually going to happen no matter how much you baby the barrel; but the hotter you run it and the more frequently you run it hot, the sooner it will happen.

Heat does accelerate wear. I use my non-chromed until it the handguards are hot in my bare hands, about 3 mags, then swap guns. Still get moa on match ammo so I do not think I hurt it.

Thanks for the feedback everyone!

Damn, I was hoping this was a BOTD thread..........

Mine get so hot (bushy superlight barrel) that you would burn yourself touching the barrel. Dunno how much abuse it can stand, but apparently quit abit.

Until you start to see the CLP smoke off the barrel, you aren't even in the realm where heat is something I would think about and you can regularly smoke the CLP off the barrel and still see the barrel life exceed 30,000-40,000 rounds in semi.

What is the smoking temperature of CLP? The flash point is probably pretty high. The only time mine has ever "smoked" is when it was new and the oil Bushmaster put on it burned off. I have never seen my own CLP smoke off the barrel.

The drop I put down the gas tube and in the piston chamber usually smoke off during the first or second round though. h.gif

Well, you'll start to see white smoke drifting off the hot barrel. If you continue firing, you'll eventually see the barrel turn white-gray as the CLP burns off and the residue is left behind. As soon as you put CLP on the barrel, it will change back to its normal color.

I've seen external temperatures as high as 615F on an M4 barrel; but that wasn't a barrel that was ever going to see much accuracy work either. Around 550-600F you can see the glue in the handguards start to smoke (black smoke and very noxious smelling). You might also check out the thread with this same title in Rifles, Lowers, Uppers and Barrels.

For the record, the military states that the sustained rate of fire for the M-16 is 12-15rpm. That means you can fire the rifle at 12-15 rounds per minute for an indefinite period of time without doing any damage to the rifle.