Ar-15 barrel boiling after 30 rounds over 10 minutes time??

[defensive007]

I notice the barrel is boiling after 30 rounds and I mean to the touch, is this normal for these barrels to get this hot? I know the direct gas impingement system delivers really hot gases through the bolt and tube but wow my bolt action is no where near this hot?

[DefensiveCarry.com]

[sgb]

Hmmmmm ........... ambient temp 90+ degrees and you're firing 3 rounds per minute for 10 minutes ............ yep the barrel gets HOT!!!

[Skygod]

Yes, it's normal. Imagine that, fireing rapid fire, hot propellent gasses and chrome and steel.

What kind of barrel you have in your AR ? What type of barrel profile ? What composition of steel ??

[defensive007]

1 in 8,5r and 4140 steel

[farronwolf]

Yep, they get hot.

A couple of weeks ago, we put 50 or so rds of 44 mag through a new rifle in about 15 minutes, standing in the sun when it was 100+ outside. Man that will get your attention when you touch the barrel/front of the reciever.

Hey just don't touch the barrel and you're good to go.

[defensive007]

How hot is the barrel allowed to get before it may cause any damage or warping? I heard a barrel that is really hot warps and the accuracy is off so it's pretty much like you are wasting ammo because the shots are not going where they need to be

[tubadude]

Hot how is the barrel allowed to get before it may cause any damage or warping? I heard a barrel that is really hot warps and the accuracy is off so it's pretty much like you are wasting ammo because the shots are not going where they need to be

I don't think that level of hot is anything you have to worry about.

I've fired my M91/30 so much in such a short period of time that, aside from the shoulder bruising, the shellac was melting off and I couldn't see the target clearly because of the heat refraction/reflection/whatever it is.

[gasmitty]

Hot how is the barrel allowed to get before it may cause any damage or warping? I heard a barrel that is really hot warps and the accuracy is off so it's pretty much like you are wasting ammo because the shots are not going where they need to be

Glowing dull red probably wouldn't even cause permanent harm, assuming you're not using the barrel as a crowbar at the same time.

Pat Rogers (EAG tactical) runs test & evaluation guns from various manufacturers through his carbine training courses. Typical round count is 1500+ rounds over 3 days, and during some drills they'll run maybe 100 rounds inside of 3 minutes. More than one T&E gun has been run past the 25,000 round mark in this kind of hard use with no apparent detriment to practical accuracy.

[QKShooter]

The vast majority of modern gun barrel steel starts out being incredibly high quality steel and is almost always "normalized" and "stress relieved" after machining as part of the SOP manufacturing process and so heat warping should not ever be the same problem that it once was.
Some firearm steel is heat treated before machining as well as after machining.

Naturally all metals in general and all gun barrel steel will expand as heats up and will contract as it cools - so the "ideal" is an even expansion which will keep accuracy within acceptable limits as the barrel heats up and then cools down.

Even if the POI changes slightly with a very hot barrel the slight variation in POI should be irrelevant on a properly designed and assembled battle rifle.

How hot is the barrel allowed to get before it may cause any damage or warping? I heard a barrel that is really hot warps and the accuracy is off so it's pretty much like you are wasting ammo because the shots are not going where they need to be

[QKShooter]

SO.............How HOT can a gun barrel get?






You can watch this one with your speakers turned off...you'll soon find out why.

[Ring]

also. FYI, a DI system has ZERO to do with how hot a barrel gets....

[Sheldon J]

Every fired a semi auto pistol with high cap mag real fast.... so Yes it is normal....

You should see what the barrel on a full auto looks like in the dark.....

[10thmtn]

I remember glowing M60 barrels back in the day...

[RevolvingMag]

A few weeks ago I went to the range with a friend of mine. And his AK. We put about 120 rounds downrange in less than 30 minutes, in 100+ weather. After 45 rounds, the wooden fore-grips were uncomfortable to the touch. I inadvertently touched the barrel at about 100 rounds in, and vowed never to make that mistake again...