Barrel Life question


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elktrout
February 15, 2009, 12:22 PM
I have always been mystified by the old claims that the 264 Win mag burned out barrels due to its high velocity, but I don't recall seeing the same claims against the newer magnums. Is the 264 really that much of a barrel burner? Was it the quality of the barrels when Winchester first made them? Or have we been so caught up in magnum mania that we just turn a blind eye to the barrel erosion problem that still exists?

What is your experience with this? Is there a velocity/bullet weight/caliber threshold where barrel erosion is exponentially higher than with other guns?

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MMCSRET
February 15, 2009, 01:03 PM
I was informed a few years ago by a gunsmith that had apprenticed with P.O. Ackley in SLC back in the last days of Ackleys career that what had been thought to be "shot out" was in fact severe copper fouling. Bullet jackets were not what we have today and we did not know about copper solvents. He had several 220 Swift barrels that had been changed out due to "shot out" and had been laying around for 30 years so he started playing with them about the time we heard about copper fouling and copper solvents, I'm guessing 1985-1990 or so and he found that they were great barrels, only fouled so bad that the accuracy had fallen off and they had been changed out. Back in the 50's we used Hoppes #9 or some other powder solvent and said it was good. Now we know differently. Look at what happened with the first generation Barnes all copper bullets, at that time we knew about copper fouling, so Barnes changed designs and now have a fantastic bullet that doesn't foul any worse than the rest of the industry, and we have copper solvents now.

pmeisel
February 15, 2009, 01:09 PM
IIRC Rick Jamison did an article on this quite a few years back (I think it was him, maybe it was Jim Carmichael). I can't seem to find it but I think the conclusion was that the issue was real but it took a helluva lot of shooting to do it.

Jim Watson
February 15, 2009, 01:17 PM
Depends on the application.
A hunter can hit and kill every critter he sees for a lifetime with a .264 Win Mag and not wear it out.
A target shooter could not get a season of Long Range matches out of a barrel. Heck, many of them don't even load the 6.5x284 to full power and still figure 1400 rounds is good service... at 1000 yards.

elktrout
February 15, 2009, 03:40 PM
What prompted my post on this subject is my brother-in-law's 264 Win Mag that he has had for over 20 years. I don't know exactly how many rounds he has through it, but it is certainly more than the "few hundred or so" that I have seen quoted as the upper threshold of barrel life.

I have shot his rifle (Model 70) and know it is a good shooter. It has accounted for a lot of game through the years.

Your comments about copper fouling are likely the answer. Thanks for your input.

nksmfamjp
February 15, 2009, 04:06 PM
Shot out is about reaching a level of accuracy where you say "no thank you". With bullets going over 3200 fps, there is much more burning of the throats due to the large charges of slow burning powder pushing them.

If the gun shoots .5 MOA and you will accept 1.5 MOA, shot out will take forever. If the gun shoots 1.45 MOA, shot out will happen very quickly. Keep this in mind. All in all, I believe shot out is an expression from the 70's where guns came out of the factory shooting larger groups and then overtime their owners wanted and could buy a new barrel, so the old barrel was judged shot out.

If an old barrel is a quality barrel, we can cut .5 " off both ends, rechamber and recrown and have a better than new varmint barrel. Only for something as precise as BR shooting would we just dump the barrel online to someone needing a varmint barrel cheap. You could do this with the factory tube, but who knows what gremlins would be released from the barrel in all that machining.

Clean it with Sweet's and Hoppes #9 alternating about 3 patches and some scrubbing with each. I would wet the bore gould and wait 15 minutes - 1 hour when switching between solvents. When you get that done, running some JB's through might scrub the final bit or fouling out. Good luck! You will be amazed at what comes out.

Horsemany
February 15, 2009, 05:25 PM
Back in the old days they didn't have the cool burning powders of today. Gun steel was softer too.

jerkface11
February 15, 2009, 05:36 PM
Yup IMR 4831 was the slowest powder you could get when .264 came out!!! With more modern powders it shouldn't be an issue.

MachIVshooter
February 15, 2009, 09:45 PM
It's not so much the barrel as the throat, and high-velocity, high pressure cartridges do accelerate the erosion. Today's metallurgy and powder technology has made it far less of an issue, but it does still exist. I'll likely have to cut and rechamber my .220 Swift inside of 2,000 rounds because I push it to it's very limits, and it needs to stay sub-MOA (closer to half) to hit praire dogs cosistently at 400+ yards.

USSR
February 15, 2009, 10:18 PM
What is your experience with this? Is there a velocity/bullet weight/caliber threshold where barrel erosion is exponentially higher than with other guns?

It's a problem with all overbore cartridges, of which the .264 Win Mag is one. It's simply a matter of a large case holding alot of powder, generating lots of hot gas down a small bore. I wish it were true that today's powders are "cooler" and our barrels "harder", but the fact is, we are still using the same chrome-moly steel they used 40 years ago, and most of the powders are still double-based using nitroglycerin. There is no free lunch. You use alot of powder to generate high velocities, and your throat gets burned out in a relatively short time.

Don

Horsemany
February 16, 2009, 12:20 AM
It is true that cooler powders have been developed in the past 40 years. Mr. Rockwell hardness scale says metal is harder too. Just because they used chrome moly 40yrs ago doesn't mean it's of the same alloy, quality or hardness.

All this however does not mean some cartridges have a greater effect on barrel life. Don is right about high volume, high pressure cartridges with small diameter bores causing more wear. I believe the amount of wear is greatly exxagerated though. I've met some shooters at my club shooting calibers that are known as barrel burners that had well over 6000 rounds on them and still shoot well. Don't shoot the barrel hot and you will have profoundly longer barrel life in any cartridge.

elktrout
February 16, 2009, 12:36 AM
Does flame temperature vary that much between slower and faster burning powders? After posting this thread, I recalled one time when my brother-in-law was having trouble keeping his 264 on a six inch bullseye at 100 yards. After eliminating all the typical suspicions of the problem (loose rings, loose guard screws, etc), we gave up. He gave me the gun and some components to try to find the problem on my next few days off work. I first cleaned the rifle. What a revelation. It took hours to get it completely clean.

Then, I loaded some 140 SMKs in it with IMR4350, went to the range, and put 10 shots into less than 2 inches at 100 yards.

He had been shooting H870 powder.

All this makes me wonder about the powder issue more than the barrel steel and also the fouling issue.

Thanks for your replies.

foxtrotter
February 16, 2009, 12:45 AM
The 220 Swift had this reputation long before the 264.
Dennis

Horsemany
February 16, 2009, 10:15 AM
elktrout

Cooler burning powders are slower burning rate powders. That means it doesn't all try to burn in the case or at the throat. Modern powders that weren't available 40years ago use the whole barrel to burn and theoretically this eases wear on the throat.

IdahoLT1
February 16, 2009, 10:39 AM
Im kinda curious what the average life of a rifle barrel is? I have probably well over 600-700 rounds through my Savage 10FP .308 within the last 2.5 years. Its a great varmint rifle(110gr. Hornady Vmax and Hodgdon Varget powder) but from my understanding, Savage barrels are real easy to swap out or even convert.

Horsemany
February 16, 2009, 10:46 AM
308 can go 3000-5000 rounds easily. Don't shoot it hot and you'll do better than that.

FredT
February 16, 2009, 01:45 PM
I rebarreled my M1A match rifle when it had 5500 rounds through it. the erosion gage read about 5.5. The guy that I gave my old bbl to said that it still shot great on his standard rifle. The throat on the new bbl read 1.5 and stayed there for a long time.

Gewehr98
February 16, 2009, 03:17 PM
The .220 Swift was one of the first with the reputation.

The .264 Win Mag was another one.

Ask the guys who shoot the .30-.378 Weatherby Mag how good their barrel life is. I've met some who tried their best to get their handloads dialed in within 20 or so rounds, because even that counted against the barrel life shot clock. :eek:

Big case capacity + small diameter bore + high working pressure + high velocity = shorter barrel life.

The powder charge doesn't completely ignite inside the cartridge, especially in a big overbore number. A lot of those powder granules blast the throat on the way down the barrel. Accuracy falls off, and you're taking the barrel off, bobbing the chamber end, running the reamer back in to clean it up, rethreading, lather, rinse, repeat...

USSR
February 16, 2009, 08:11 PM
Cooler burning powders are slower burning rate powders. That means it doesn't all try to burn in the case or at the throat. Modern powders that weren't available 40years ago use the whole barrel to burn and theoretically this eases wear on the throat.

Bunk! Alliant's Reloader 22 is a modern, slow burn rate powder (Great powder, by the way), but it is a double-based powder (i.e. contains nitroglycerin) and is MUCH tougher on the throat than a faster burn rate powder and single-base powder such as IMR4895, which has been around since WW2.

Don

Horsemany
February 16, 2009, 10:47 PM
Don

That's one example. Are you honestly arguing there have not been a plethora of new slow burning powders developed in the last 20 years? I'm generalizing here. There are exceptions of course as you have pointed out. New burn rates have revitalized some older cartridges allowing them to do what they couldn't when they were originally developed.

USSR
February 16, 2009, 11:15 PM
Don

That's one example. Are you honestly arguing there have not been a plethora of new slow burning powders developed in the last 20 years? I'm generalizing here. There are exceptions of course as you have pointed out. New burn rates have revitalized some older cartridges allowing them to do what they couldn't when they were originally developed.

Not at all. In fact, about the only progress in the last 20 years has been in developing better slow burning powders. However, that does not mean that new double-based powders burn "cooler" and will not erode a throat in short order in an overbore cartridge. Reloader 22 is a poignant example. I love this powder.:) With it, I can safely load my .30-06 tactical rifle to send 190gr Sierra Matchkings at 2900fps, something I can't do with any other powder. But, the benefit comes with a cost: my barrel life will be somewhat less than if I used a single-base powder. Double-base powders are nothing new; they've been around for many years. All the progress has been in coatings to control the burn rate. Guys are deluding themselves if they think that we aren't using the same barrel steel and powder composition that we used 40 years ago. In short, there has been no major firearm related breakthrough. You load alot of powder behind a small caliber bullet, and barrel life decreases.

Don

Horsemany
February 17, 2009, 12:05 AM
All the progress has been in coatings to control the burn rate.

Yep. I agree.

You load alot of powder behind a small caliber bullet, and barrel life decreases.

Yep. I agree. THere's no free lunch. I'm saying that perhaps the barrel burning issues of 40 years ago were
a. exaggerated by the ill informed(no forums back then you know. You had to get your info from the gunshop).

b. slightly exaggerated from steel that may not be as hard as modern steels. You don't find modern guns with dented recievers like guns from the 40's and 50's. Hardness tests are common when rebarreling mausers and alike. You don't hear much about hardness testing when rebarreling a Rem 700. I own a Pre 64 with a small dent on the reciever from the factory.

c. slightly more common muzzle erosion with less selection of powders. H-1000 is a perfect example of a modern powder that provides the lowest cup pressure of any Hodgdon powder for 264 WM in their manual. It wasn't available in the 60's.

d.Poor cleaning techniques and a low percentage of shooters cleaning copper from the boor can diminish bore life. Anyone who's seen bore cleaning products from the 60's knows what I mean. No bore guides and very poor rods.

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