I have read several posts on different web sites that all claim that a 7mm STW is an absolute barrel burner and will
quote "burn out a barrel" on average with as little as 500 rounds. I dont claim to be an expert, but that dose not make sence to me becase I am not loading any more powder in my new 7mm STW than in my 338wm, btwn 73 to 76 grains of IMR-7828, and R-22, and my 338 still consistantly honest .75" five shot 100yrd groups after approx 600 rounds.
So is it true that a 7mm STW loaded in the mid range as I am doing realy have that much shorter a barrel life than say my 338wm?
I will also say I have and use only the best gun cleaning tools such as bore guides and Deweys coated rods and fallow strict cleaning techneichs(sp) as perscribed by the likes of Schillen and Pac-nor.
Thanks for any input.

One of the facts you must consider is you are burning that powder in a smaller bore so you are magnifying the effect. It's not so much you are "burning up" the barrel, it's the fact that you are burning up the throat and that's what makes the accuracy go. The best was to combat that is to not shoot the rifle until the barrel is hot....it takes patience but it will pay off.

There are a couple of reasons why a smaller bore on the same size case greatyli increases throat "wear" or "burnout"

Firstly, when gas expands it also cools. A 338 bore has about 50% more area than a 284 bore. Thus for any given amount of bullet movement, the 338 bore increases the volume by 50% more thana 284 bore. Thus the gas is cooler.

Secondly, the temperature is not only higher in the small bore, but far more concentrated on a much smaller area.

Mike

Assuming you're using your STW only for hunting, and as long as you are judicious at the benchrest when doing sighting and load development, your STW barrel will last you exactly as long as a .308 Winchester or a .22 rimfire -- your lifetime.

Hi big foot,
I think if you use light bullet your barrel will have a short life (800-1000) shot, by heavy bullet life is longer why bullet velocity is lower. A good cleanig product is very important. If you use Moly-coated bullet the barrel life will be much longer.
ciao FAINA