Question about Case Length After Fire Forming

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c-ross
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Question about Case Length After Fire Forming

Post by c-ross » Tue Mar 23, 2021 7:48 pm

I have a batch of cases that have been fired twice. They are RP cases. Was sorting through them after my last trip to the range and the case length is between 2.086 and 2.088. I am surprised that they have shrunk so much. Should I trim all to 2.086 or just load as is.

Crl

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PhilRich
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Re: Question about Case Length After Fire Forming

Post by PhilRich » Tue Mar 23, 2021 7:54 pm

Leave as is - that's what I do. If you resize them the length will increase.

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desert deuce
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Re: Question about Case Length After Fire Forming

Post by desert deuce » Tue Mar 23, 2021 8:13 pm

Bought a case of 500 remington 45-70 unprimed brass.
Average length 2.080"
After two firings and two annealings I stretched some to 2.115 and or a little more then fire formed them with cornmeal.
Avg length now 2.105" after forming with cornmeal, and squaring mouth of case.
Can't really tell the difference in performance on silhouette
Sometimes you get the chicken, and sometimes you get the feathers!

rgchristensen
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Re: Question about Case Length After Fire Forming

Post by rgchristensen » Thu Mar 25, 2021 2:05 pm

Many years ago (~20), I bought 200 45-70 REM cases and formed them to .40-65. They were trimmed to 2.135", the length of the chamber in my Browning. Every year or so for a few years, I measured the lengths and trimmed any that had lengthened in use, maybe 5-6/year. Last 10 years, no change. There are still around 180 of them left, some lost, some stepped on, some mislaid. I'm (guessing) they have been fired 60+ times apiece and are still hanging in there. I hope to live out my days shooting this same lot of brass.

CHRIS

rgchristensen
Posts: 119
Joined: Sat Jan 16, 2016 10:51 pm

Re: Question about Case Length After Fire Forming

Post by rgchristensen » Thu Mar 25, 2021 2:05 pm

Many years ago (~20), I bought 200 45-70 REM cases and formed them to .40-65. They were trimmed to 2.135", the length of the chamber in my Browning. Every year or so for a few years, I measured the lengths and trimmed any that had lengthened in use, maybe 5-6/year. Last 10 years, no change. There are still around 180 of them left, some lost, some stepped on, some mislaid. I'm (guessing) they have been fired 60+ times apiece and are still hanging in there. I hope to live out my days shooting this same lot of brass.

CHRIS

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