Reading various links about the high pressure, fast, short & fat cartridges: I read one that said you can get to the point where the pressure is so hot, it starts to melt barrel. (Thus shortening barrel life & causing erosion.) So, if this is right... what kind of pressures start to take us into the barrel-eating category?

Back in the 220 Swift days, barrels had shorter lives but that was due to velocity, I understand. (Never owned one, tho)

never heard anything like that, I do know shorter cartridges are more efficient when it comes to powder ignition. I would think they would be easier on a barrel.

I think Hatcher was the one who figured it out a long time ago- the more powder you burn, the faster the throat erodes.

That being said, a short magnum should, in theory, last longer than its standard magnum of the same caliber.

Your understanding is slightly incorrect. What "wears out" the barrels of high-velocity rifles is NOT FRICTION from bullets, but eating away of steel due to the temperatures of the high-pressure gases melting and carrying away barrel steel every time the gun is fired. The more powder you burn, the higher the pressures are, and the longer the peak pressures/temperatures are maintained, the more steel is cut away at each shot.

ALL high-pressure smokeless powder loads wear out barrels this way! But cases that hold more powder in a given bore size, which produce higher velocities and higher sustained temperatures do it more than ones with smaller charges. This is why the .220 Swift ruined barrels in a relatively few rounds. Additionally, people who insist on firing so fast you can fry an egg on their barrels, regardless of the size of their cartridges, are doing their best to keep barrel makers in business.

Thanks for the comments. I have done very little shooting with any fast cartridges; I had a 22-250 Win but the accuracy was much less than what I should have gotten. So, rather than get it reworked, I sold it off.

Search engines pull up info on shooters with WSSM's in kind of a convoluted manner... but after seeing what is reported, between feeding problems and barrel recalls, I will have to set it aside as a prospective buy. Looks like Winchester and Browing put these rifles out way too fast. Problems like that could end whatever chance these have of becoming a viable market item.

Yeah, but the marketing people have hyped them so well, the country is full of suckers who are running out to buy them, before they get the facts! Remember Herter's, Inc.?? ALWAYS FIRST WITH EVERYTHING NEW!!?? Same with these cartridges! I guess the gun companies have to keep reinventing the wheel to stay in business!

I've heard a different theory where the hot gasses harden a very thin layer of steel in the throat of the gun which makes the metal very brittle in comparison to the relatively flexible and resilient barrel metal. Successive firings cause the hardened metal to flacke or chip away.

I believe it is pretty well established that it is the "cutting torch" effect of high temperature, high velocity gases eroding the steel by melting it and carrying it away that "wears out" barrels. Undersized bullets magnifies this effect. For example, the M1911A1 of WWII vintage had .452" groove-diameter barrels, but GI hardball bullets miked .4490 to .450"". Barrel life of this combination was around 5,000 rounds or less, despite the fact that the pressures of this load were only running around 18,000 PSI. Examination of the shot-out barrels showed excessive gas cutting. When bullet diameter was increased to .452", this stopped!

I've heard of that happening in 1911's, but in rifles with longer barrels, if its simply gas cutting, why don't we see 'steel' fouling further down the barrel?

Essentially because the tiny fragment of melted steel is pretty much vaporized and exits with the rest of the powder gases. Remember, it is a very miniscule amount with each shot, not like the glob of lead you get from the melted base of a lead bullet!