View Full Version : How hot is too hot for ar15 barrel?

August 13, 2012, 02:27 PM
How hot is too hot when shooting my new S&W Sport? While shooting my new rifle Saturday the barrrel was smoking hot and put a blister on my sons finger when he accidentally touched the barrel when shooting it. We only shot 200 rounds total. Should I let it cool off and when should I do this. As you can tell, I am new to the AR world. My kids and I are avid shooters of handguns, shotguns, and non AR rifles and have been bitten by the AR bug.

the rifleer
August 13, 2012, 02:33 PM
It should be fine to shoot at a rate of about 1 shot every 2 seconds continuously. You can shoot a mag as fast as you can pull the trigger, but I would wait several minutes after that before shooting it again.

You will never actually damage the barrel from shooting it too fast on semi auto, it just wears out faster the hotter it gets. Unless you are going to shoot 20,000 rounds through this, it isn't really an issue. I like to be nice to my barrels and i take my time between reloads and don't shoot super fast. But like i said, you aren't actually going to hurt it.

Also, I leave the bolt open. Both for range safety, but also because it cools faster.

August 13, 2012, 02:47 PM
Is that the rifle with the Melonited barrel?
I wouldn't worry about the heat unless your gas tube starts to melt. ;)

August 13, 2012, 04:26 PM
Is that the rifle with the Melonited barrel?
I wouldn't worry about the heat unless your gas tube starts to melt.

He's being tongue and cheek but he's right. You can do a search of why Colt went to the SOCOM version of the M4 and it'll give you a lot of good info on the breaking point of ARs in terms of heat. Lots of good info out there about this. If your barrel is the 1 in 8 melonited version it's extremely durable and you need not worry about it getting too hot unless you're running it with a slide fire stock or bump firing it (don't do this).

August 13, 2012, 04:28 PM
It's 33 pages long... but have a read about barrel temperatures on an M16A1 (http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA019649). It's pretty interesting.


August 13, 2012, 07:37 PM
Thanks for the replies, I appreciate it

August 14, 2012, 08:42 AM
I haven't read Creepers link yet (its loading) but I've shot some M16a1s with some pretty hot barrels.

More then once in SE Asia I turned them red. Squirted oil or water on the bolt and kept going.

Back in the early 80s I was running a sniper school for the NG when an RA Lt came up and asked some help with his ammo. Seems if he didn't show a usage he would loose next years allocation.

I figured why not, so he shows up with 35K rounds of M193 (along with 24K rounds of machine gun ammo.

I sent one guy to the unit to pick up 10 M16a1s, gave the guns the afternoon off to get rid of the ammo. They flat turned those barrels red in no time. (we did the same thing with some full auto M14s). The M16's lasted longer then the M14s not to mention its easer to shoot a '16 full auto.

M16's remind me of the Brilcream commercials, "A Little Dab will Do Ya" (old folks will know what I'm talking about"

A dab of oil will keep you're M16 going all day long.

Now to read the article.

August 14, 2012, 09:28 AM
On AK's, I've seen some of the Utube flicks where the wooden handguard actually catches fire. I'd say that's pretty warm!

I our rapid fire NRA match stages, I've never had enough heat coming off the AR handguard to even make note of it.

In the same matches, using a 1903A3 in 30-06, the handguard got so hot that the metal attached to the wood parts blistered me.

Never noted any barrel damage or had any ill effects, however.


August 14, 2012, 11:12 AM
When it catches fire, you should consider taking a short break. Other than that, you're good to go.

August 14, 2012, 11:25 AM
as others have said its fine. Question though? how did he touch the barrel? during shooting or while it was at rest? If he had issues with it while firing I know a few companies make little hand stops to prevent your hand from sliding to far forward. (needs a RIS though.) Just thought I would toss that in.

August 14, 2012, 03:13 PM
Venum, he burnt his knuckle on the end of the handguard. I have ordered an extended magpul moe handguard and will try that. Thanks for the info.

August 14, 2012, 04:21 PM
The Army taught that the sustained rate of fire for any of it's M4/M16 series weapons is 12 - 15 rounds per minute. That means you can shoot at this rate indefinately without damaging the rifle or yourself. While they don't mention it, you can usually run a weapon at a higher rate of fire for a finite period of time - probably two or three minutes in this case.

But the 12 - 15 rounds per minute is probably an oversimplification. The different versions of this rifle have barrels with different lengths and diameters and profiles. I don't know if they've changed the steel from version to version.

There is no doubt that you probably won't worry about this if you are in a fire fight. And it's Uncle Sam's rifle. So as long as the barrel doesn't burst and rounds don't cook off, you probably won't care.

But if it's your baby, and you are at the range engaged in a death struggle with paper targets, I think keeping to the sustained rate of fire isn't a bad idea.

August 16, 2012, 08:39 AM
If anyone would know, it's Kraigwy.

400+ degrees is not uncommon if you're doing a lot of shooting. Of course, like Kraigwy said, you can get them hotter to the point where they're glowing.

I would not recommend getting them that hot, as the metal in the components will begin to break down very fast, resulting in less life. But if you have the money to replace your parts, then go for it.

August 18, 2012, 07:14 AM
the handguard would catch on fire before the barrel gives out.

there's a video of a full auto, going through like 20 mags and the handguard is on fire.

Big Shrek
August 20, 2012, 12:36 PM
Yer firing too quickly, slow down, actually AIM, and enjoy better accuracy!!
When you can outhit Jerry Miculek at under his time, THEN you can speed up!! :D