In making cases for the 7.62 X 41, a batch of 06 mil. SL42 and an often fired deprimed batch of .257 RP with split necks were used.

The only difference in processing was the primer pocket decrimping to the SL42s.

Process

Clean.

Cut to rough length using home made trimm die and hack saw.

Deburr and chamfer.

Anneal using propane torch and cake pan with water.

Near full length size.

Trimm length .010" under max length.

Turn neck diameter to fit chamber ( a little trial and error).

Load close to but lower than max.

Fire form.

The outcome was that 20% of the military SL 42 cases had split necks after fire form and another 10% after the second firing.

None of the often loaded cases made from .257 RP cases had split necks.

All cases had tight feeling primer pockets when reloaded with #34 primers.

You can draw your own conclusions; the intent here is only to pass on information.roger

Old age is a high price to pay for maturity!!! Some never pay and some pay and never reap the reward. Wisdom comes with age! Sometimes age comes alone..

Are you sure the brass was fully annealed?

quote:

Originally posted by SST:
Are you sure the brass was fully annealed?

The only thing I can say for sure was both groups of brass got the same treatment. Was the old military brass suffering from enbrittlemnt? Was there a significant metalurgical difference in the two groups? Your guess is as good as mine, Sam.

Knowing where the SL42s came from ; they were fired "OVER" 40 years ago and the cases shelved away in a cardboard box that was rotted when I got it.

Well I reloaded both batches near max.today. Wed. we'll see what happens. roger