Hunting rifle: barrel life

[deonh]

A hoary old chestnut but one we debated over several beers at the range yesterday. Quite simply what, in your opinion, is the accurate life of a barrel (by caliber):?

[THOMAST]

About 1,5 -2 seconds..

[Sean Murphy]

This has a lot to do with caliber but also a lot to do with the owners expectation of accuracy.

A bench rest shooter will say a barrel is shot out when it starts to shoot out of one hole. A hunter with a standard hunting rifle will not notice that kind of drop off in accuracy simply because the average hunting rifle is not capable of bench rest levels of accuarcy in the first place.

Moderate calibers like 7X57 or .308 will last for maybe 10 000 rounds with a good quality barrel before a hunter notices any major drop off in accuarcy that requires a new barrel.

Other like 22-250 Acley Improved will burn out the throat of an equal quality barrel in around 2000 rounds. Bearing in mind that these types of calibers are relied on for long range accuarce on small targets, the owners expectations will be higher that that of the .308 bushveld hunter who only has to hit the heart lung area of a kudu at 80-100 meters.

So the answer is relative to the caliber and to the level of accuracy required.

This debate is also a major consideration to military buyers who select new rifles and calibers for issue. Barrel life is a major consideraton when buying hundreds of thousand of rifles. That is one of the reasons why calibers like .308 Win and .223 rem are chosen over others like 22-250 and 7mm Remington Magnum. Their is not doubt that the latter would perform better in many applications, but if the recruits barrel is shot out by the time he has finished basic training then that government better have a big budget for the military.

Sean.

[Longshot]

What Sean said.

Moderate velocities and larger caliber = longer time before throat erosion messes up accuracy. Think barrel life of a 30-06 vs 25-06, the 25-06 caseneck "concentrates" the burning powder more than the 06 will due to smaller caliber and will create more pressure too. This will cause the 25-06 to need a new pipe before the 06.

The way the rifle is cleaned plays a big role in barrel life too, correct cleaning will increase barrel life.

[deonh]

Thanks okes. I know it's not very scientific and with a multitude of variables but what would you say (shots fired) is the barrel life of a decent, factory .270 and .243 barrel?

[Webster]

Deon - I cannot answer your question but you can significantly prolong the life of your barrel if you seat the bullets to touch the lands and reassess when groups start opening. You might need to make your cartridge a few thou longer to touch the lands again - accuracy will return. This only applies in cases of throat erosion - not if the barrel as a whole unit is shot out and the rifling is smoothing off! Then you are looking at a new barrel.o depends on the propellant you use, how hot you load, what bullet you shoot etc etc. But I like the question! Why not ask the life of a 243 barrel if only ever used with 100gr standard PMP factory ammo? Let see if someone can give us a benchmark to work off. I would also love to know the answer to your question as I have a 243 and 270. ???

[deonh]

But I like the question! Why not ask the life of a 243 barrel if only ever used with 100gr standard PMP factory ammo? Let see if someone can give us a benchmark to work off. I would also love to know the answer to your question as I have a 243 and 270. ???

Hi Dave. Ja, assuming normal usage using normal ammunition (factory or reload). The figure of 2500 rounds was mentioned for both .243 and .270 while debating it at the range. Personally I think this is massively conservative.

[Webster]

Ja - I agree - that is way to conservative! I would double that at least! Maybe an expert can tell us ;D

[THOMAST]

I have a 7mmRM which I bought in 1987. As the throat began to erode, I seated the bullets out further, to keep close to the lands. I noticed that although velocities were still high, accuracy began to deteriorate in the last year or so (bullet no longer in the sweet spot).
Went to the range with a lot of ammo loaded to max length, taking along a hand press, a micrometer seating die and a bullet seating depth guage. Fired a 3 shot group, let barrel cool down, seated the next 3 rounds 0.010" deeper and repeated exercise. When I reached the seating depth where the cannelure of the bullet was at the case mouth, the grouping had shrunk to 6mm, ctc, a perfect triangle! Only problem was that the velocity had come down from 2870fps (175gr bullet) down to under 2600fps! Now I had accuracy, but no speed. To have both I need a new barrel. I calculated that the number of rounds fired through the barrel in all these years (including working up loads with different bullets and propellants) was close to 3500.
A bullet traveling at 2870fps down a 26" barrel spends 0.0007549 seconds in the barrel. Multiply that by 3500 rounds =2,64215 seconds of barrel life.

[kaspaas]

Anyone with experience regarding .375 H&H barrel life?