Just worked a load for my 338 at 90 gr, but it was all new brass. Went for a quick test session today with now 1x fired brass, and 90 shot terrible. Looks like 90.3 is the new spot but needs another session to confirm. How much does your load change from new to 1x fired brass?
Load Development Change with New Brass
- Thread starter mdmp5
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2 trains of thought here, one, fired brass has been expanded dia wise and grew in length, therefore more powder is needed. Size of the case makes a big diff too, way more room in a 338 Lapua case.
The other is, now that brass has been formed, it will require less powder as now the brass will not grow as much on subsequent firings and will need less to equal the original pressure generated.
Every gun is different.
The other is, now that brass has been formed, it will require less powder as now the brass will not grow as much on subsequent firings and will need less to equal the original pressure generated.
Every gun is different.
I found with 338, the brass continued to expand after 3-4 firings. I was shocked when my headspace readings changed. I was constantly chasing my loads. Never did solve it. Just moving on instead. Enjoying 6.5 now
