I was always taught not to let a rifle barrel get too hot (say over 120 to 150 degrees F) or it would reduce its life. My experience with heavy volume shooting has been more with shotguns and handguns, and primarily I use my rifles for hunting/load development, so I’ve always fired a few shots and let them cool.
I’ve only really “shot out” one rifle barrel that I felt didn’t last for very many rounds (before the throat eroded and the groups blew up), but I always let that rifle cool pretty well and usually wouldn’t fire more than 2 to 4 shots without cooling.
BUT I see these serious long-range rifle guys burn through 10+ rounds about as fast as they can (so the wind conditions are consistent) without seeming to care at all about running their super expensive barrels really hot and (possibly) reducing the life.
I have a friend that insisted that his rifle was bedded well enough that it still shot great while it was really hot - and he would shoot it significantly hotter than I would. It seemed like he burned that barrel out really early. (Both the barrels discussed above were magnum case capacities, so maybe that was more of the problem than the heat).
Of course I’m sure it depends on the caliber, load, ambient temp, etc., (and maybe barrel quality and cleaning procedures) but have you guys seen evidence that letting a barrel cool - and keeping it from getting fired a ton when it’s already hot - will make great accuracy last any longer?
Thanks,
Kyler

Kyler,
As a competitive rifle shooter I cannot avoid the fact my barrel is going to get hot before the course of fire is complete. I have always looked at barrels as disposable, if it burns out I get a new one, it is just a cost of playing the game. Now weather the barrel getting hot speeds up the process of throat erosion I cannot definitively say one way or the other, but my guess is that it does contribute to increased erosion.

Thanks, it makes sense that it would take a lot more than 150 to 200 degrees to accelerate erosion of steel or stainless steel, but it sure seems like a common thought among shooters.

I can say with conviction long strings of magnum calibers kills barrels. When the Army fielded the M2010 300 Win Mag sniper rifle it was essentially a M700 in a chassis system. I was supporting a range when an infantry unit was firing them on a KD range. They fired way too many rounds in a very short amount of time, w/ suppressors. We had an opportunity to borescope them after 6-800 rounds on the rifles and they were toast. 2-3” of dry lakebed cracking/erosion and a 2-3” lead to the rifling.

I read somewhere that each time we fire a high-powered rifle, the molecules on the bore surface momentarily liquidise but that if we then let the barrel cool most return to solidity.

However, the story went, if you immediately fire more shots, those 'liquid' molecules will be washed out. This explained, the writer said, why some machinegun barrels could be worn beyond decent accuracy within about a hundred shots.

What say you, dpcd?

I saw a friend burn out a 243 in a few hours of Pdog shooting.

Don't know how many hundreds of rounds or maybe a thousand plus.

I warned him. He just shrugged and kept shooting.

His half inch rifle went to 2 inches and then a new barrel.

I would not have thought that there was any doubt that overheating a barrel will shorten it's life.

It's also definitely possible to create enough heat even with a bolt action. MDT published a test on Youtube if you want to go looking for it.

The one thing that is in question is at what temperature this starts to happen.
My thought would be that damage occurs every time the hottest part (probably the interior of the barrel at the lead) reaches the lowest published tempering temperature for the steel used. For 4140 this is under 400 degrees F.

This probably happens with every shot though, and for every degree the barrel is hotter, the longer the hottest parts will be hotter than annealing temperature. Thus in all probability if one had to draw a graph of barrel temperature versus damage done per shot it would be a parabolic curve.

You buy barrels to win matches or kill prairie dogs. If shooting fast helps accomplish those goals, then damn the torpedoes and pass the ammunition.

John

I guess it depends on how rich you are and what the rifle is.

Installing a new barrel would probably cost almost as much as a s/h modernly cheap rifle in good condition. So, I try to space out my shots even between those in a group and so far have not needed any new barrels.


With expensive guns, big refurbishments rarely add much to the value - they get marked down because they're not original.

Back in 1958 when I was 14. I bought a 1917 Eddystone full of cosmoline for $15. The chamber was tight.

Many times at targets, rock busting and prairie dogs, running coyotes etc. I had it so hot it blistered my hands lots of times, I fully believe if it had been dark enough it would have glowed pink. Even when I first got it. It never made less than 1 1/2" groups with 110, 150 or 180 gr. Like most kids, I shot it a LOT and often.

The serial number shows it was in that big pile of lend lease guns returned. Seems like from China. You can take a look in the book: Model of 1917 Enfield's. In 1973 having some work done to it the gunsmith checked it with gauges and said the chamber was very loose and it would make "that dandy .300 Win I had been talking about". Another local smith had a new reamer. So I had that done.
I would bet it had at least 10,000 '06 loads thru it before then and likely 6=800 .300 since.

In 2000 I shot a cow elk at 200 yards with a 180gr C/L that blew up on the surface. Never even got into the near lung.

Talking with Paul Box at Sierra. He said "that's common with core locs. My first and only with many of them. He sent me some: "elk Killer bullets". 200gr Game Kings to test.

Amazingly they made 5 shot groups of 5/8" to 3/4".

Three years ago a buddy got a new bore scope. I got that gun out first, then several others. It
still had the original 1918 barrel on it. The bore was alligatored clear to the muzzle. Yet to look down it. It very shiny. The rifling could barely be seen.

Having the funds and knowing I couldn't stand knowing how bad that bore looked. I had it replaced.

It was just zeroed for the first time 2 weeks ago. Might be 30 shots thru it so far.

George

So what is your conclusion, George?

Though accuracy seemed to remain, you do mention various symptoms of wear such as the chamber loosening and the bore becoming 'alligatored'.

Though I've used Core-Lokts, I can't speak with authority on them - but the hound hunters here used to like the 220-grainers for sambar, which are relatively tough critters.

Hello Paul:

Several things.

Don't shoot until the barrel is too hot to touch bare handed.

Try other brands and weights of bullets, one may shoot much better than any others.

Surface blow up at 200 yards proves there may be a fluke even in large lots of the same bullet.
It CAN happen. I have been thinking that may have been a buy of 1000 bullets as I was loading for 8 of us with .300Win.

Last I heard, some over 45 head of elk had been killed with those bullets.
One from about 30 feet, others to a guessed at 400 yards. Never a failure except mine.

Just because the bore has been cooked so bad you can't stand knowing about it being that way.
Sure doesn't mean they won't still shoot very accurately.

Keep shooting them until accuracy fails, then replace it.

Enough to please you Paul? lol
Cheers mate!
George

Thanks George,
yes,I guess you've covered it.

I would think twice before replacing a barrel. On occasions rechambering crosses my mind but my buddy who makes falling-block rifles from scratch is rarely encouraging, even in that.

Meanwhile, after firing a shot at a target, I check the chronograph, bullet fall and case expansion before shooting again.

quote:

You buy barrels to win matches or kill prairie dogs. If shooting fast helps accomplish those goals, then damn the torpedoes and pass the ammunition.

John

I agree!

I've shot over 20,000 burrowing rodents in the last 5 years. I currently have three (of my 10) varmint rifles getting new barrels (Dan Dowling, 'smith). I'm a long way from 'rich', but I don't fish, golf, or hang out at bars.

When I have targets in front of me I keep shooting! I do try to rotate rifles when there is a break in the action. I do like trigger time.

quote:

I'm a long way from 'rich', but I don't fish, golf, or hang out at bars.

Goes a long ways in being able to afford things.