Settle a discussion point for me... barrel wear vs velocity/pressure.

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Pond James Pond

New member
This topic came up the other day when idly discussing ammo choice. I have always understood that steel-jacketed is more punishing on barrels than copper jacketed. As such, choosing decent brass-cased, copper-jacketed ammo will be kinder to one's rifle than choosing steel-cased/jacketed.

However, another party pointed out that the jacket material was only really an issue with higher pressure and velocities and in the super-fast .223 cartridge, that is an issue for barrel wear, but in 20-odd% slower 7.62x39, the difference between steel-jacketed and copper was negligible.

Is this true?
(I have no horse in the race, other than having thought differently.)
 
Both will wear, but the AK steel bullet would wear less on a per-shot basis. Slower means less heat from friction, but it will still be an issue.
 
Jacketed (copper / guilding metal) wears more than lead (it's harder) even at the same pressures. Steel jacketed (which is normally "soft" iron (just enough of an alloy to be technically steel)) is softer than barrel steel, but it is still harder than copper.

Friction (from both material construction, pressure/velocity, AND bearing surface of the bullets) is part of the wear on a barrel.

The other part is the erosion of the steel from the high temperature, high pressure powder gas. Friction wears then entire barrel length, erosion happens mostly at the chamber end, where the heat & pressure of the gas is greatest.

Even lead bullets can wear out a barrel, but it normally takes tens of thousands of rounds, due to both the "softness" of lead, and the generally lower pressures of lead bullet rounds.

Jacked rounds, even at low pressures, will wear out a barrel sooner than lead, look at the .45ACP. A low pressure round, yet enough jacketed slugs will wear out a barrel.

Another factor is the RATE of fire. Rapid fire causes greater wear (meaning more wear in fewer rounds) The hotter the barrel gets, the "faster" things wear.

It is a balancing act or, if you prefer, a ratio, between all the factors.

Hope this helps..
 
So if I were to take a round of X psi with a given steel jacketed bullet at Y fps and take a round with a copper jacketed bullet with the same X psi and Y fps, the steel will wear out the barrel that bit faster.

But if I took that steel jacketed bullet and used X-10% psi and therefore got Y-10% fps (for example) then it might be the copper jacketed that wears the barrel more quickly, being the faster, hotter (celsius) and higher pressure combination.

Correct?
 
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I think the data given is true, but reality would dictate that you will never shoot enough steel jacket ammo to make a difference unless you are wealthy and able to buy and shoot thousands of rounds.
 
In 7.62x39 the difference is real, but you have to ask whether the cost savings of shooting steel jacketed bullets makes more economic sense than spending more money on copper (gilding metal) clad bullets.

I think that over the thousands of rounds needed to wear out a barrel, shooting the cheaper, and harder, bullets will allow you to save enough money to pay for a new barrel (or in the case of an AK a whole new rifle). So I'd say that the wear difference is negligible from a cost perspective.

Jimro
 
I like jacketed, I like brass brass, or put another way I do not shoot steel cases. I like embed ability. My dies last longer and the shine of my chambers stay shiny longer.

F. Guffey
 
The reason that I don't think that x-10 will make a difference in barrel wear is that steel is much harder than copper.

Now, x-10 may well reduce the amount of burning of the leade, which is the usual problem in "shot-out" barrels and reductions in accuracy. The leade will burn long before the lands will wear down.
 
Nice link!

An interesting read which validates what many had said about savings off-setting barrel wear.

In addition they ran the guns hot, and they were all higher pressure .223s.

The wear shown would probably be somewhat mitigated with lower pressure x39...
 
Besides what I said in my prior post about probably not shooting enough ammo in a lifetime to make a significant difference, I would also tend to think that, before shooting enough steel jacket to wear out rifling, you would have significant throat erosion.-

Granted, there are some out there who may have enough money to shoot that many rounds, but, as has been pointed out, they also probably have enough money for a new barrel or even a new gun.
 
The general answer has me happy to shoot cast bullets at 1400 fps through a single shot rifle! Heck what's not to like? 50,000 rounds through some of the old schuetzen rifles with less than 1/10th of a thousandths measurable wear at the muzzle, and still shooting as tight as they did when new!
 
Throat erosion by hot gasses will finish of your barrel long before the steel jacket wears down your lands. Maybe if you find a water cooled Maxim you can get enough rounds through one to do the experiment so.
 
Yes but erosion is not the major problem. Years back there was a proper metallurgical study of barrel "wear" . Heat is the problem !! The hotter the barrel is the more it will absorb carbon from the hot gases . That higher carbon steel in the heating and cooling cycles cause micro-cracking .
Want longer barrel life ? Keep the barrel cool.Take some time between shots .
 
I put 6300 rounds of jacketed match ammo down a Savage .308 barrel and the rifling looked like it was not even worn. However, the chamber had eroded more than 90 thousandths in a chamber that was already pretty deep when I bought it. I eventually had the rifle rebarreled because I had to seat the bullets out so far that I couldn't get enough of the bullet in the neck to maintain neck tension. Since I am an accuracy freak, I just wasn't happy with my groups opening up because of varying velocities. The new barrel has a shorter chamber and actually shoots better than the original.

From my experience, I would think that the barrel wear at the chamber is the more important factor and I doubt steel or jacketed ammo would make much of a difference in that kind or wear.
 
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