short case life / neck cracking

[moooose102]

i am just starting to reload my .300 win mag for the second time. last time i was doing this, about 8 years ago, i had quite short case life. usually 2-3 reloads and then the cases would crack in the neck where the bullet seats. i was not crimping them. i read a few weeks ago about annealing the cases with a torch in a pan of water. i did not do this last time, i do remember reading about it, but i was not comfortable doing it so i bypassed it. is this something i should do every time i resize the cases? the biggest difference this time is i am going to try to just neck sizing instead of full lenght resizing. i ALWAYS just use brass fired from my gun, and it seems like it makes more sense to do this. please post your opinions! thanks, d.s. p,s, should i be doing this to my 45/70 brass that i will be full length resizing as well?

 

[Roccobro]

I read through all the links in this thread and learned a lot. It seems 45/70 lasts through MANY firings without annealing and light loads. Bottle neck cartridges seem to vary.

http://thehighroad.org/showthread.php?t=312513

Justin

 

[critter]

I reload for both the above calibers. The 45-70 first. They are, more or less, a straight walled pistol-like case. I use them repeatedly and they have a long case life. They usually fail as a case mouth split, but that is after MANY trips through the reloader/gun. I do not anneal them and I won't bother.

In my 300 mag, I full length resize them to be SURE they will chamber while hunting. I have never had a case mouth split on me. Since SOME belted mag cases may stretch and fail just above the belt, I am VERY careful with my inspection of these cases. I also limit mine to THREE reloads and have NEVER had one fail either way. Obviously, I do not anneal these either.

I would think you have a particularly hard set of cases there. I'd try a different brand to see if they, too, split. If so, there may be some deminsional abberations that need to be addressed. If not, it is the particular brand of brass and you may want to change brands.

Even if it is hard brass, though, annealing would probably solve your problem. Sorry that I have no experience in doing that.

 

[Mark whiz]

Resizing is much harder on bottle-necked cases than on straight-walled cased. Straight-walled cases will probably wear out before you have to worry about splitting - and if you do start splitting, a quick trimming should solve that problem for another 10 to 20 reloads.

Annealling is typically done for the case shoulders and not the mouths, although the mouths probably get enough heat to soften them up a tad. I usually anneal my .308 cases after 3 to 5 reloads and have gotten great case life with that method.

Let me ask, do you add any lube on the case mouth (inside or outside) when you resize? If you don't, you might want to try a small amount - I dip my mouths in motor mica when I resize, it tends to help the expander slide thru a tad easier. If you are already lubing the mouths, you might want to try a little less lube or a different type.

 

[cougar1717]

I agree with critter. It's been my experience that large magnum brass (like 300 win mag) does not have a long lifespan. After 2-3 reloads most show stretching above the belt or the primer pockets have expanded. Since the brass is relatively cheap and guns chambered in magnum calibers are relatively expensive, I just play it safe. To me, the extra cost of the brass is better than having a failure.

 

[L.Puckett]

moooose102,

I normally expect 12-15 reloads (fairly hot) out of Lapua or RWS brass. At $1.25-1.60 each (.300WM) they better.

To get this I anneal the necks every other reload. If you encounter "belt bulge", the Innovative Technologies Magnum resizing die does a good job of resizing the case, although a bit more time consuming.

I have not expeienced any primer pocket loosening on Lapua, RWS, or A191 mil-spec cases.

LP