Hi guys, I have just started working with a 257 Wby Mag. . I was told yesterday by a guy at the local gun shop that a 257 Wby would be shot out in 500 rounds or less. I do not feel like this is correct. Imput please.

A lot of this comes from a time when barrels were of a lesser quality. Definitely, barrel life will be dependant on your pressure levels. If you consistently load at a very hot level then maybe 500 rounds would have a serious effect.

I have a borescope and check my barrels occasionally, my 257wby does show some throat erosion but less than my 300Ultra. Neither of them is bad. I suppose I have a couple hundred rounds through the 257. It shoots fine in the 3500fps range so even though I could load it hotter, I don't.

I used to load the 257 and 300 to the very limit until I came to my senses and realized I really wasn't gaining anything except increased barrel wear and enlarged primer pockets. Both shoot TSX, 100 and 168 respectively, in the 3500 range with head expansion in the .0005 range. Both work fine and I don't think I am prematurely wearing the barrel.

I'd sure like to hear more input from long-time .257 Wby owners. I have one and I may start shooting some milder loads if 500 round life is, in fact, the case.

From reloadbench.com

"There once was a time when everything written about such cartridges as the .257 Weatherby Magnum included an apology for it's barrel life, but such opinions are now as outdated as high top shoe's and Model A Fords. The advent of tougher barrel steels and, possibly more important, a greater awareness among shooters of the importance of cleaning rifle barrels properly have proven that the big game hunting accuracy life of a barrel in .257 Weatherby Magnum (and other like cartridges) is in excess of 2000 rounds. This, of course, is assuming that the shooter does not wash out the chamber throat by subjecting the barrel to a high rate of sustained fire. Allow a barrel in .257 Weatherby Magnum to cool down every three shots an it will last the average shooter a lifetime."

So I would expect maybe 1000-1500 for excellent accuracy.

Sure, you could shoot the barrel out or at least the throat with light bullets at highest velocity, but only if you shot it heavey and didn't allow it to cool...I know a guy that shot one out in one day, even after several of us warned him to let it cool down, He just shot it over and over for hours and it went South about 3 PM.... I suspect you can shoot any barrel out at one session if you try hard enough...

I watched a guy at our shooting range shoot his 338 about 500 rounds as fast as he could...I watched him a little, then decided I didn't want to be there any longer and left, I figure he was a few bricks short of a load..Later found out he was a deputy sheriff in the neighboring county...What a dunce.

I think that the guy who tried to shoot 500 rounds through his 338 as fast as he could was more than a few bricks short of a full load. What was he thinking?

I don't know what he was thinking, I didn't bother to talk to him, scared he might freak out on me or give me a ticket..He was a Jerome, Id. policeman...

Heres a quote from the bottom of page 202 of the Nosler 5th edition reloading manual, with regards to the .264 Winchester Magnum that also applies to the .257 Weatherby:

quote:

The .264 Winchester Magnum, like many cartridges with big cases and skinny bullets, has developed a reputation as a "barrel burner". We have found that surprisingly long barrel life can be expected, even with full power loads, provided the shooter takes care not to overheat the barrel and employs frequent bore scrubbings.

quote:

Later found out he was a deputy sheriff in the neighboring county...What a dunce.

That doesn't surprise me a bit!

quote:

Originally posted by landkiller:
I think that the guy who tried to shoot 500 rounds through his 338 as fast as he could was more than a few bricks short of a full load. What was he thinking?

What a first class idiot !!

For informational sake..

I can tell you that once a barrel is considered shot out, if you can live with less velocity, SR 4759 can still keep it shooting pretty darn accurately for quite a while still...

SR 4759 has cleaned up quite a few accuracy pigs in my gun rack...

of course using it for off season shooting, it can stretch that barrel life quite a bit.. so that you can use the boomer loads come hunting season...

I did hear an unique answer once to a question given to an older gunsmith.. how long is the barrel life on a magnum?? his answer was.. oh about 8 lbs of powder worth...

My 257 is 10 years old and still going strong after at least a 1000 rounds through it.

Cleaning and cooling are the keys, as lots of guys have said.

The cooling of the magnums was demonstrated to me by a Weatherby MK V 300 win mag. It was warm On the 1000 yard line aboard Quantico MCB, an acquaintance and I were after a 8" gong. I shot and reloaded 20 rounds in a very short period of time. The tube was so hot that it was burning off the generous coat of oil that is present at all times! Upon cleaning the barrel exhibited small pits throughout it's length and the lands have been gas cut lightly. My later research has allowed prevention of further damage through the knowledge that the cooling of the barrel is essential. the cure was cleaning with a very light abrasive (Break-Free Bore Paste) twenty times after no more than 10 rounds, it is back to it's old self.

There are folks that achieve 5,000 rounds from a .220 Swift and still get 1" groups.....if that can be the case the .257 Weatherby cn do marvels as well.

I'd expect (properly cared for) 3,500 rounds from a .257 Wby.

I think there are several important factors. (1) The powder capacity relative to the bore diameter. (2) Barrel temperature when shooting. (3) The use of boat tailed bullets. (4) And if the chamber has freebore. --- Jack O'Conner said that a 7MM Mauser would generally have a shorter barrel life than a .270 Win because the 7MM chambers generally have freeboring to accomidate the long 175-grain round nose military bullets. He also clamed that gas leaks around boat tailed bullets and erodes the bore more than is flat based bullets are used. I burned out three 7MM Weatherby barrels. I never shot them with hot barrels and note that the .257 Weatherby has the same powder capacity but a smaller bore. The first barrel took about 1,000 rounds before accuracy dropped off. The next barrel showed a significant accuracy loss at around 1,000 rounds. I used a lot of 160-grain Sierra boat tailed bullets with the next barrel and it showed a significant accuracy loos at 600 rounds. The gun was then rebarrel to 7MM STW which has more powder capacity but no freebore and it still is still shooting well at around 600 rounds and with no throat erosion visable with the naked eye.

IOWADON
I have never heard of the problems you mentioned concerning boat tail bullets. Can you point me to more data on the subject. Thanks.

I wonder if the boat tail causes an effect similar to a "shaped change" as used to focus hot gases in an armor piercing projectile.

Perhaps just between the case mouth, freebore, and the lead slope of the rifling hot propellant gases are being concentrated and focused onto the barrel steel by reflecting off the sloping surface of the the boat tail as it moves past this area, shortly after this area pressure has drop too much to cause harm.

Maybe this focus effect always occurs when shooting boat tails but only causes damage in cartridges that operate at the highest pressure levels 63K to 65K psi. I'm just speculating as I have never read of boat tailed bullets causing increased ware on the throat lead area before.

Maybe the use of spherical powders could slow down the erosion. I read somewhere that ball type powder were supposed to help reduce throat erosion. Imagine what the inside of your shotgun choke would look like if you shot square steel shot. Extruded powders have edges on the individual granules. Something to think about on those over-bored high capacity cases, all that rocket exhaust bead blasting the chamber throat.