View Full Version : LC 7.62x51 (308) resizing
<MADDOG>
09-18-2020, 14:46
Sorry if this was addressed, I seen nothing in the search.
All right gentlemen, I have challenge which you may know how to fix, and I have not run into it before with any other brass. I have some current reloads with 7.62 x 51 LC, with some I started to process, and have run into an issue.
I used small base dies (both RCBS and Lee), but approximately 8% of the resized brass does not fit the Lyman case gauge (including after trimming to length). About the same % of previously loaded rounds were also confirmed to close hard/if it all on a bolt gun after failing the gauge.
I have read elsewhere that it is best to first run the brass through a .30-06 die, then back through the .308. Is this true? Or should I accept that M240's eat brass and just gauge each one prior to priming?
In my experience case gauges only are good for length, gerth is another issue.my reamers are sloppy in a case gauge.
beast556
09-18-2020, 22:21
I had the same issue with 7.62 brass. I switched to winchester brass and haven't had any issues. I only load match 308 so I figured it wasn't worth my time to mess with the 7.62 brass.
I added more lube and it actually improved things. Seemed to resize easier and move the brass more efficiently.
Then I started roll sizing all my 223 & 308 brass before I process it. Problem solved.
<MADDOG>
09-20-2020, 06:11
I had the same issue with 7.62 brass. I switched to winchester brass and haven't had any issues. I only load match 308 so I figured it wasn't worth my time to mess with the 7.62 brass.
Agree, I have not had this problem on any other commercial brass at all. This is specific to LC 7.62.
Hoser, that looks like a nice gadget, and if I still needed the volume that I did when I was in CO, I may have bit!
OP:
My suggestions are:
-lube those cases very generously.
-I'd think that if the SB dies (unless somehow not set up properly) would resize more than the "30-06" approach, so cull them and move on.
(I suppose if you have the 30-06 die, it cant hurt..... but I wouldn't go out a buy the thing. Your SB dies should've done it).
<MADDOG>
09-22-2020, 16:14
OP:
My suggestions are:
-lube those cases very generously.
-I'd think that if the SB dies (unless somehow not set up properly) would resize more than the "30-06" approach, so cull them and move on.
(I suppose if you have the 30-06 die, it cant hurt..... but I wouldn't go out a buy the thing. Your SB dies should've done it).
Yea, that is where I am at now...
I played with all three of my dies the other night, & adjusted up/down all to check my sanity. There was absolutely no difference made.
I "smoked" a couple of cases as well. It appears from the markings left by the gauge, there is a "bump" at the shoulder, the head/body is too far expanded, or in a couple of circumstances, both.
Educated guess: my particular lot of .mil brass has M240 or worse mixed in, and the LC thickness/composition is just to thick to overcome the fire forming that occurred in whatever chamber it was fired in.
Overall - I will chalk it up to learning lesson, and if I buy another bulk order, I'll expect 20% cull rate on the brass as worse case.
Unless your brass has the LR headstamp for M118LR all modern 7.62 will be exclusively fired from MGs .
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