I have seen on numerous occasions where folks will say shoot a heavier bullet as it's slower and your barrel life will be longer. Seems that is a misnomer. Actually just the opposite it seems

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Bullet weight, mostly, determines barrel throat life. Why? The heavier the bullet, the slower it accelerates, and the more time the flame from burning propellant has to torch into the metal. Even though a lighter bullet is burning more propellant, it’s the intensity of the cutting that does the most damage.

Oh, 100% the lighter the bullet, the faster you wear out a barrel. Take a 260 Rem, 6.5 CM or 300 WM. Push a lighter bullet faster, and it wears out the throat much faster than pushing a heavier bullet slower. It has to do with heat. The lighter bullet will have more powder and/or a faster burning powder than the heavier bullet will and generate more heat at the throat.

Point in case. Back when I was running a 260 Rem in competitions. Everyone was running the 140 VLD's (or 139 Scenar, or 140 Amax) then. Most were about 2780 to 2820 fps with a 140 grain bullet. Berger came out with the 130 grain VLD, so I started tinkering with it. I got the 130 VLD up to 2950 fps and shooting TIGHT!!! So I shot a few matches with that 130 grain VLD. I would also measure my throat wear and see how much the throat was eroding. The throat was getting a little longer with the 140's and I was keeping track of my round counts. When I went to the 130's, my throat started moving back much faster. I was keeping track of round counts also, and it was eroding about twice as fast as the 140's were.

A lot of the 260 Rem shooters I know switched to the 130 VLD, also. One of the guys burned up a barrel in 1100 rounds shooting the 130's at 2900 fps in a 24"-25" barrel. Barrel life in a 260 Rem should be about 2500 rounds, give or take a few.

I was running about 43 grains of H4350 with a 140, and 44.5+ grains with the 130 grain, same lot of powder. Does the 1.5 grain extra powder cause the added wear? I don't know. But I know for sure that the lighter bullets will kill a barrel much faster than a slower, heavier bullet will, no doubt!

I then decided to switch back to the 140's. The faster barrel wear was not worth the benefit of the 130 speeds.

Also, a lot of shooters talk about rounds being a barrel burner and such. If you don't shoot it much, I say go for it. Get that caliber that pushes a bullet a little faster. Speed = more energy, and speed kills. But it comes at a price of recoil, blast, and noise. But most of your common calibers will do the job just fine with good shot placement. I lean towards something that is more "shootable".

After talking to Frank Green over at Bartlein Barrels, the new 26 Nosler was burning up the test barrels in as few as 400 rounds. That's nuts!

Here is the full article.

http://www.mssblog.com/2016/08/12/factors-in-barrel-life/

Yeah, I highly disagree that heavier bullets wear out barrels faster. It's speed and heat that cause the barrel wear. Slightly longer dwell time of a slower bullet vs. more powder, more heat, and more speed of the faster bullet. The faster kills the barrel.


In his article:

"A bolt-gun can have its chromemoly barrel pulled and “set back” to prolong its life. Simple: cut a half-inch or so off the chamber-end of the barrel, rechamber it, back in business."

What? Since when can you not set a stainless steel barrel back? I've done it ( I won't do it again, but I've done it).

I would wonder if erosion from unburned powder entering the bore might be a factor. A light bullet gets moving quicker, so more of the powder gets pushed into the bore, to burn. It gets pushed through the throat area.

On the 26 Nosler, I would guess that a fair percentage of the powder, highly compressed, makes it through the throat before it gets a chance to burn.

Hot gasses too, of course. This is more of a question than a theory... Enquiring minds want to know!

I am not sure which theory is correct but since its really only the throat area that gets torched its not the bullets velocity traveling down the barrel that causes wear. Its the heat in the throat.

I'm with Chad on this one.

I will say who cares, shoot what you want. A buddy of mine summed it up for me "They make barrels while we sleep". FWIW - any gunsmith will agree with me

Extra pressure doesn't cause the erosion. More friction does. The faster the bullet, the more friction there is. It's similar to fluid dynamics, the more friction there is, the higher the pressure will be. As friction reducers are added to fluids, things like "moly" have been used to coat bullets to decrease friction. The bullets increase in velocity but barrel life is also extended.

Light bullet + high velocity = faster throat erosion. I've got barrels that are now scrap metal to prove it.

Chad is right.

Barrel Lives Matter!

Sorry, I got nothing to add but this popped into my mind.

a little off the op, but, Bartlein has a good write up for breaking in barrels, but what do they know

Followup article and clarification on the barrel set back.
Still emphasizing lighter bullets longer barrel life though so if that bothers you look away.

http://www.mssblog.com/2016/08/19/throat-erosion-part-ii/

I posted this comment:

In a given caliber, lighter-faster bullets will burn a barrel out faster than a slower-heavier bullet will. When the 260 Rem was a top caliber in competitions, multiple competition shooters ran the 260 Rem. We shot mainly the 140 grain bullets @ 2800 fps, but many switched to the 130 VLD @ 2900-2950 fps when it first came out. We were seeing as few as 1100 rounds of accurate barrel life, with most running 1500 rounds with the 130 grain. With the 140 grain, you can expect 2000-2800 rounds of accurate barrel life (I got 2600 rounds shooting the 140 grain.) If the lighter 130 grain wears a barrel out faster than a 140 grain bullet in the 260 Rem, how does a lighter bullet going faster prolong barrel life? I have also seen this with other calibers, like a 300 Win Mag.