Home Forums Hunting & Shooting Hunting Rifles How many rounds to "burn out a barrel"?

With an average velocity rifle (say up to 3000fps mv), how many rounds does it take to puke a barrel?

I know this varies from barrel to barrel, but what's the average and the variability range?

The big thing here is not so much the amount of rounds total but how the rounds are expended. In other words you can make it last quite a while or if you really work it over hard it can be made to puke with a lot less.

This one is gonna depend tons on who you shoot and what kind of tube you're into.

Mark D

One other thing is that people will accept different levels of puking...

I'll take the wag that a not abused tube should go around 5000 rounds and retain big game hunting accuracy. With abuse you can trash a tube in 2000 rounds or less, and with care and luck, you could be good for 10,000 rounds. Even with handloads, the cost of a barrel is much, much less than th cost of the componets required to wear the tube out.

You can do it with as few as 400 rounds (7 mm STW, data from a barrel maker), even fewer with some experimental cartridges. The damage occurs at the beginning of the barrel where the 3,000+ degree F hot gases start down the barrel. If you aggravate erosion by firing many rounds in a short period and heating up the steel, the erosion is worse.

Stainless steel is more erosion resistant than chrome moly steel, so you often see numbers like 5,000 roundsfor CrMo steel and 8,000 rounds SS for accurate barrel life.

It is in the hundreds of thousands for .22 rimfires...jim

As above, it's easy to burn out a barrel quickly, even in .270 and '06, if you shoot one after another, and get the barrel hot enough to draw a blister if you lay it on your bare leg. Don't ask how I know that. It was a long time ago, anyway. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

All I can really add is that though I don't know how many rounds it had fired, I've bought a used .270 and a used '06 that wore out very quickly, and never shot terribly well, and I've guessed that they were burned out by being shot quickly and without letup. I've seen a good many folks do that. I got less than 500 rds through them, and probably less than that int he '06 I had, before they just wouldn't shoot worth spit. That's not many ctgs., and I'd guess they'd fired maybe 500 times at most, and certainly less than 1,000 rds before I got them. The '06 is now a Whelen and the .270 is now an '06.

Then there's a buddy that used to have a M-700 in .264 WM. He shot the 100 gr. bullets at very top velocity, and he'd fired some 2,500 rds. when it burned up in a house fire. It would still do a 3 shot cloverleaf, with all 3 generally touching, and it was never touched - strictly as it came from the factory. He only shot it once every 5 to 10 min, though, and never more than 6 times in an hour's shooting. Never let the barrel get hot. He was doing long range shooting with it, and the 100 gr. bullet expanded well way on out yonder - the reason he chose it in the first place. He killed two at just over 700 with it. Of all the rifles he lost in that fire, and there were over 100, that .264 was the one he laments most, and he always treated it special because it warranted it, and in fact DEMANDED it if its useful life was to be what it needed to be. A man just takes CARE of rifles like that one.

It's heat that destroys barrels and throats, and about ANY "deer caliber" can and will develop sufficient heat to burn a barrel out quickly. Witness what happens with machine gun barrels. It's not the caliber, it's the heat buildup that "burns" them.

You have to define "puke". I have a 22-250 barrel that completely took a dump, went from sub-moa to 5 moa+ in about 10 shots.

I have a 7mm WSM barrel that is about shot out right around 3000 shots, but my standard is a bit different for that rifle. I've given up chasing the lands, as they are WAY out there, and accuracy is still about 1.5 moa-ish. It's probably good for another 1000 or so before I dump it.

How a barrel is constructed makes a difference. Boots Obermeyer claims that the larger the differential between land and groove, the longer the barrel lasts. I tend to agree based on what I've seen. I further think that the 5R types of rifling lend themselves to longer accuracy life.

Long way of saying that a 308 will probably go 5000 or more, and a 257 Roy will probably go 1500. Although....... you could easily puke a 308 in 500 rounds if you tried hard, and could coax a Roy to 3000 if you babied it.

Interestingly, I used the puked 22-250 barrel as a brass burper for my 22 PPC, and it shoots great again after lopping off the chamber end and rechambering. It won't win the Super Shoot, but it'll damn sure keep 55gr bulk bullets inside a squirrel at 200 yards.

Not quite along the lines of your story, but the phrase holds.

I have a second hand Model 700 .243 of unknown round count before I bought it, I've put maybe a thousand rounds down the barrel. The lands are far enough out that I can't seat most bullets to touch them and still fit in the 2.8" magazine. Top end loads in the manuals that supposedly generate in the 3000 fps range are only doing 2800 and change out of this 22" barrel. Never bothered to really look close and I don't have borescope anyway, but I'm guessing this is pretty good indication of a lot of "freebore" built up over the life of the barrel.

And yet this thing will still put three Hornady 100 grain Spire Points right close to 3/4" or a hair less about 4 times out of 5, and good Sierra 85 HPBT's will shade that by a tenth or two for five rounds.

Don't know what all this particular rifle tells us about burned out barrels in general, guess it just makes me appreciate older barrels that still shoot good when all the rules and generalizations tells us they shouldn't shoot worth beans. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

I read once where they did some testing at Camp Perry, I think the write up is in one of the Sierra load manuals.

As I remember the test was done with military barrels and 30-06 ammo. It said the accuracy actually improved with the first three thousand rounds fired, held steady for another two thousand, then declined to the same as a new barrel with the next three thousand.

I guess they showed that an 06 with military loadings was good for at least 8,000 rounds.

HunterJim and Blackwater are very correct here.

I have burned our several barrels in calibers from .257 to .338 and the single greatest influence on barrel wear is not who makes the barrel or how well it is made, though that is a legitimate input, but how frequent the shot are fired.

Then there is "your personal" definition on what constitues a worn out barrel.

If the rifle is a varmint or bench rig, extreme accuracy is way under .5MOA or, perhaps anything over that is not within your requirements.

To a big game hunter, that will also change depending on whether you are shooting deer in forest country at under 100 yards, or elk in the next county.

Load development kills barrels fast because you are shooting groups and loading frequently.

I loaded for 3 different 257 Weatherby's over the 1970-80's and shot one out after 1,014 rounds. The last 40 or so where really only to expend the ammo as accuracy had reached 4 MOA by about 950 rounds.

There was no visable wear in the barrel until over 650 rounds were fired and no "real" drop off in accuracy until over 800 were fired.

That rifle fired almost exactly 400 rounds in the field and the balance on the bench. The barrel lasted 12 years.

Alternatively, if you used a .257 Weatherby as a hunting rifle in the US, I would consider that you bought your grandson a pretty nice hunting rifle even if he isn't born for 40 years yet.


AGW

I'm trying to find that out myself. I presently have a 7 Ultra with about 1000 rounds through it and it shoots as good as ever. However, I never get the stainless barrel too hot to touch comfortably and I think that is really the key. When it does give up the ghost I will go with the same caliber and a Hart barrel. Incidently, a friend shot the barrel out of a new 22-250 on one prairie dog expedition several years ago.

Thanks guys. Nice bit of experiences there. I mostly buy used rifles, and that leaves the door open to some nut having shot 20 rounds as fast as he could with the barrel smoking hot so he could hurry up and go home from the range. Which also means that a used rifle could puke very quickly if it had been mistreated. I haven't bought a used bummer yet, but that could change at any time I suppose. Since I seem to like the "older" guns, I get worried at times that I'll find a nice looking one that shoots lousy.

BTW, when bench testing loads, I'll try to shoot at least two, shooting each in rotation. That way, the barrels don't get too hot, and I ought to get good barrel life that way.

Re those '03 Springfields, and the 8,000 rd barrel life, I wouldn't doubt that a bit. Back when they were made, barrel steels weren't as good as they are now, but the military ammo wasn't loaded to the levels many of us load to now, either, and it was single based powders without nitroglycerine content, IIRC. This and the pace of fire typical on most military ranges helped keep those barrels from heating up to much. I think I remember Dad, an old '30's Marine, speaking of a drill sargeant or range master getting "a bit perturbed" when a shooter shot too quickly and heated up a barrel. Of course, taxes back then were something like 12-14% of GNP in those days, too, so ..... every penny counted in the military budget. Must'a been nice, eh?

Shooting more than one rifle when load testing at the bench sure helps us squeeze more use out of our precious shooting times these days, while still letting us keep those bores from wearing out any sooner than they ought to. I'd just love the time to wear out many MORE!

Also, just for "keeping your eye up," cast bullets can offer a real advantage here also. If you can work up a good accurate load, you can practically forget about barrel wear with them. Lower pressure, cooler burning temps and softer lubricated bullets have pretty much negligible wear effect on barrels - something we might just make a lot of use of if we just did so. Position shooting, snap shooting, and just plain plinking gets to be a lot of pure ol' FUN, and we can shoot a LOT more, too. In court, they call that a "clue!" <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

AGW,
No disrespect intended, but I'd wager a large sum of money that Boots Obermeyer has tested and burned out more barrels in his life than you've ever seen. He seems to disagree with you, and given his track record, I think that in such a debate, Boots wins going away each and every time. It ain't even close.

Here's what he has to say about it:



IOW, given the same treatement, a cut rifled barrel will last longer. Argue all you want that it's the way a barrel is treated that determines life (you're right), but to dismiss the fact that comparing apples to apples, cut rifled barrels last longer is foolish.

CAS and AGW,
I appreciate both of your input. Probably a cut-rifled barrel with purposely deeper grooves would last longer than a similarly treated button-rifled.

On the other hand, I am talking factory barrels, and I don't know that any of those are cut-rifled (are they?). Also, it would seem heat is the big destroyer of either type of barrel; simply that a cut-rifled might last even longer given decent treatment. As to buying older used rifles, my concern is really that I will never know if someone has heated a barrel way up, and that will burn out any barrel rather quickly I suppose.

Thanks again for the input.

OK Guys:

So how "hot" is 'hot"?

I typically load 2 rounds, fire, work the action, and fire again.

Then I get up and get the other rifle. Load 2 rounds, fire, work the action, fire again.

Swith rifles, repeat three cycles then let the barrrels cool. (5 minutes.

Repeat until I have shot 50 rounds total.

Then I go home.

It takes about an hour.

The barrels get pretty warm in the summer. Not so warm in the winter.

I never got a blistered hand, but how hot is hot?

BMT

DD,
A borescope will tell you what a barrel looks like from the inside, but even then you won't have a good idea of what type of life is left.



Bingo! You will never really know for sure how a rifle was treated, it's a crap shoot. Generally speaking though, I've found that the rifles that looked to have been babied in the outside, are in about the same condition on the inside. People who abuse bores are generally not shy about adding a few whacks to the outside.

Not letting my dog into this fight but do have a question.

Rifle barrels are cut to certain standard dimensions, right? In a ".308" barrel the bore diameter - the distance across the lands - should be .300" and the groove diameter will be .308" This so a .308 diameter bullet will be engraved .004" by each land and the bullet itself will fill the grooves fully to seal the bore.

So how do you make the "depth" between the lands and grooves greater in a cut rifled barrel? I'm assuming he means the "difference", not the depth, between the lands and grooves so not to pick on a minor semantic point.

Anyway - how do you do that and stay in spec with bullet manufacturers? You'd have to make the bore diameter tighter or the groove diameter greater, the former would raise presures and the latter would greatly lower them by in effect sending an undersized bullet down the bore.

If I'm reading that right then something doesn't jive.

Or perhaps I completely misunderstood and he's talking about making the lands wider and grooves narrower or vice versa?

Again, not looking to argue anything but this has piqued my curiosity and so I'm looking for a better understanding of this.

Jim,
The best I can explain it, and I'm not a barrel maker so bear with me, is that the distance between groove diameter (say .308 for 30 caliber) and land diameter (.300 for a button rifled barrel) can be increased with cut rifling so say .308 and .298. Moving that much more metal with a button is not realistic, but removing it with a cutter is.

Boots also says that this only works with certain types of rifling (his 5R for example) that allows the bullets to deform in a way that is conducive to accuracy.

As far as the "depth" of the groove, Boots also says that he does in fact like a groove diameter .0005 (I think) over the standard size.




Here's what Boots has to say about that:



and



One of the things that is so great about guys like Boots, guys that have real world experience and have tried things that others simply speculate about, is that they prove that what should be conventional wisdom, sometimes isn't.

It'll be a sad day in the firearms industry when Boots is no longer around.

Okay, I can see that, especially about the cross sectional area. As to the greater groove diameter, of course a bullet will obdurate somewhat under the 50K psi or more sending it down the bore, so even .001" oversize would still let a bullet bump up to fill it.

Interesting voodoo, these barrels. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />

CAS,
Good points but neither dakotadeer nor I were comparing barrel manufacturing methods and such was reafirmed that it was in fact factory barrels he was talking about.

I would also expect there are many many readers to this forum who have more experience that I. I can only however, speak of my own experience. It won't be valuable to some and that's a fact.

To add a point of humor to this, why don't you measure a few brands of bullets in various bullet weights and see how wide ranging factory bullets are. When you are talking about differences of .002" is barrel spec's, that becomes very interesting when bullets can often vary .005" in some brands over others.

In the end, you still have to shoot them to see what happens.

AGW