I went to load a few rounds of .375Win today and had serious issues with cases buckling.

These cases were not full length resized, but my sizing die has no expander plug anyway. I flared the case mouths. If I flared the case mouth any more, then they won't fit into the bullet seating die.

I tried to load 220gr Hornady FN and buckled 3 cases. So then I tried a 235gr Woodleigh and had the same result.


I suspect this f**king Winchester brass is just too soft.

WTF is going on here!?

Is the seating dies attempting to crimp before the bullet is seated? That is usually the cause of this problem.

Also are you using a Lyman M die or the Lee toll to flair the case mouths?

Larry Gibson

I would try to apply some graphite to the case mouth before seating the bullet.

It is one of two issues. Either the bullet is to tight a fit in the case neck or you have the die set to crimp to much.
Had a similar issue with a .458 Lott and it turned out to be the expander ball was not long enough to stretch out the neck enough to accept 450 or 500 grain Barnes X bullets. But in your case suspect the die is set to crimp to much.

Your sizing die has no expander plug, what does the inside of the casemouth measure in diameter before you attempt to seat a bullet?

I very much doubt that the brass is too soft. Not very likely with Winchester brass.

I would agree, you need to run an expander into the case, not just to bell the neck, but to expand the case where the bullet rests against the sides of the case. Most dies for a straight wall case are made that way, what brand are you useing?
I have a question about your woodliegh 235's
How long is the bullet nose from the crimping groove? Have you shot anything with them at 375 win vel to see if they open well?

RCBS states to lube the case mouth with their nylon brush and some case lube prior to seating the bullets. It should help if you aren't already doing it.

And what you had happen may be nothing more than dies that are out of adjustment, as has already been mentioned.

You need an expander. http://www.midwayusa.com/viewP...productNumber=547980 Sale price 29.25

243winxb, the set you link to is precisely the RCBS 3-Die set that I am using.

No the dies are not improperly adjusted; it's not crimping too soon...

And yes, I lubed the inside of the case/neck.

The expander plug and case bell die, doesn't open up the case mouth enough, while the tapered plug for belling the case mouth opens it up TOO MUCH.
If I turn that thing in just a bit too far, it actually bells the case mouth to the point that the case will not enter the seating die.

That plug is not designed correctly seems to me. The tapered part of the plug is way bigger then it needs to be. It should be turned down on a lathe, to ~0.376"-0.378", then the thing would open up the case mouth just right.

I've got a buddy that dabbles in gunsmithing stuff and I'm gonna talk to him about the problem, maybe customize that expander/case bell plug.

Meanwhile I ordered a set of Lee Pacesetter dies. They were recommended to me by a fella that's familiar with this specific problem Re: the .375Win.

So I'll see if they do the trick for me.

quote:

Originally posted by theback40:
I would agree, you need to run an expander into the case, not just to bell the neck, but to expand the case...

I have a question about your woodliegh 235's
How long is the bullet nose from the crimping groove? Have you shot anything with them at 375 win vel to see if they open well?

I'm using an RCBS 3-Die set. It has the sizing die, expander-case mouth belling plug and the seating die.


As to the Woodleigh 235grs, those are intended for the .375H&H, but the velocity range is listed as 1900-2800fps.
I believe I can safely load them to 2000-2100fps in my M-1895 .405Win and at close range on black bear I figure they will open up adequately. But no, I haven't tested them yet.

This was supposed to the day I did!!

quote:

Meanwhile I ordered a set of Lee Pacesetter dies

The Lee dies are about the worst you can buy for this application. The Lyman M expander die is better. There are also expanders sold by Track of the Wolf and Buffalo Arms that should do what you need also.
What you may be have problem with is the short stubby bullets tilting in the die. Spin the case if you can to get the bullet to sit straight up. Forget that if your press leans back as some do. Just be sure to get an expander that allows you to start the bullet into the case with your fingers.
My RCBS dies work perfectly for this application but I use the larger expanders for loading the similar .38-55 and it has an even thinner case than the .375 Win.

back the seater dies out a full turn . crank the stem down till it works

^ jeffeosso, you absolutely nailed it!

Oh man... one of those embarrassing moments...

I screwed up. Wasn't adjusting the seating dies correctly. I decided to re-read the instructions and got the thing set properly. It's working perfectly of course.

You'd think I'd know after all the loading I've done over the years!

quote:

Originally posted by Doubless:
RCBS states to lube the case mouth with their nylon brush and some case lube prior to seating the bullets. It should help if you aren't already doing it.

And what you had happen may be nothing more than dies that are out of adjustment, as has already been mentioned.

Wow, first I've heard of leaving lube inside the neck for bullet seating. I usually try removing it w/ a bore mop & spray degreaser for more uniform neck tension?
There must be something not quite right w/ the die setup. I load for the 375win & have never had that happen. Try backing the die out so no crimp is applied , then seating then crimping.

+1 surprised to know that RCBS suggests to lube the case mouth prior to seat bullets. I sometimes use graphite for that purpose, NEVER oily stuff

quote:

Originally posted by Demonical:

You'd think I'd know after all the loading I've done over the years!

heh, trust me, it wasn't a guess -- i have done EXACTLY the same thing, after decades of reloading, i did it a year ago with the 45/70 ...