338 LM Sizing Die Problem

[Arbiter]

Equipment: Lee single-stage press, RCBS full length sizing die and seating die, Lee QD die bushing, and Lapua once-fired brass.

I've had this press for a few years now, primarily for loading 308, and have no experience with problems like this. Up until now I've been neck sizing 308, and never had any issues at all. I bought the RCBS 338 LM dies a few months ago, and managed to immediately get a case stuck in the sizing die due to a boneheaded moment of forgetting case lube. Bought the RCBS stuck case removal kit, got the casing out, and finished reloading my first batch of 50 rounds without any other press/die issues.

Fast forward a month to this evening, and I'm trying to load a batch of 50 pieces of Lapua once-fired brass. The cases were tumbled for the better part of a day and a half, bringing them to a fairly high polish. I began resizing, applying a fingertip or two's worth of Imperial sizing wax onto the body of each case, and got through about 30 cases before I encountered one that had a bit of extra resistance going into the die. It squeaked a bit as it went in, and then on the up stroke the rim ripped off of the case head, leaving the brass seized solidly in the die. Thirty minutes of cursing and improvisation later, I got the brass out using the RCBS kit. I used Q-tips and a chamber mop to clean out the sizing die, assembled everything back up again, and it occurred to me to try an already-sized piece of brass again as a test. Popped one of the very first deprimed and resized cases back in the die, met strong resistance right as the ram approached the base of the die, and then sure enough it got stuck again and ripped the rim off. After getting it apart, I noticed that the decapping pin was bent, but I'm fairly certain that happened during the removal process rather than being the cause of the stuck case.

What the hell is going on here? I can understand a stuck case due to a lack of lube, but can excessive lube cause the headspace of the die to shrink to the point that cases won't enter? With the decapping rod assembly completely removed I cannot get one of the previously deprimed and sized cases to re-enter the die now - it stops when the mouth of the case encounters the beginning of the neck sizing portion of the die. Loosely dropping in a live factory 338LM cartridge, it also stops fast at the beginning of the neck portion of the die. Looking inside the die with a flashlight shows no signs of gunk or buildup anywhere inside. How can a die be working fine for thirty pieces of brass, then suddenly "tighten up" and stop working?

Right now I can't do anything without a new decapping pin assembly, but now I'm worried that I have absolutely no idea how to fix this problem - every piece of brass that enters the die, regardless of condition or sizing, is getting stuck solidly if enough force is applied to completely seat it. What am I missing?

 

[ChrisGarrett]

I've been loading the 338LM since Jan. of '06 and have used most of the dies from the big makers.

I've never stuck one in all of that time. I've used RCBS CaseLube II and Imperial most of the time. Sometimes I do notice that as cycles accrue, headspacing gets harder to control, to the point that I generally neck size only for 3-4 cycles and then fiddle with things after they get hard to chamber.

I've got between 11-13 cycles on my initial batch of 80 Lapua cases and 8-9 cycles on 20 Norma cases.

I'd suggest that you try another die and/or try another lube and see if things don't get easier.

Chris

 

[joemusso]

I use the Rcbs FL dis as well as the redding bushing FL dies
I think the key is as stated above change you sizing lube.

Thank you
Joe

 

[farmerbrown]

Hi,

I've found with the .338 LM it's very important to lube the outside of the neck.

The "old days" of dabbing the neck In a bit of graphite isn't good enough.

I haven't had one get stuck, but I've gone close.

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