Issues After Annealing 300 PRC

jraulsten

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This may just be a perceived problem but I've never seen this before. I had 50 rounds of Lapua brass with two firings and decided it was time to anneal with AMP Aztec. Everything went fine with the annealing process but when I full length resized, I noticed it was just a little more difficult than usual. I say a little bit because the die has always seemed to be very tight to me (Redding Type-S Full Length Bushing Die). Anyway, my die is set for .002 setback and the first few I did bumped the shoulder back .004-.005. I suppose this could be due to lack of spring-back after annealing? I adjusted the die for .002 and continued resizing. I noticed every case has a thin shiny ring around the case at the shoulder junction. I measured the area and it was the same as that of a resized case that had not yet been annealed. I other thing I noticed was that the shoulder junction is now very sharp where prior to annealing it was more rounded. If you drag your fingernail down the shoulder you can feel it slightly catch at the junction. Is this normal? Almost makes me wish I hadn't annealed!

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I've never had issues with any other caliber and like I said, it seemed to be excessively hard to resize the 300 PRC brass even before the annealing. I'm starting to think there is either an issue with the size of the Lapua brass or my particular sizing die was cut a little too small.
 
I can't say about Lapua or ADG, but on Hornady - I have 4 loadings on some (medium loads) and have not had to bump shoulder yet. No annealing. With firing pin removed, bolt closes with no effort at all.
OTOH - My rifle doesn't shoot nearly as well as yours either. Maybe I am doing something wrong 😳
 
I can't say about Lapua or ADG, but on Hornady - I have 4 loadings on some (medium loads) and have not had to bump shoulder yet. No annealing. With firing pin removed, bolt closes with no effort at all.
OTOH - My rifle doesn't shoot nearly as well as yours either. Maybe I am doing something wrong 😳
What kind of dies are you using? Do you feel like you need to use more force to size the 300 PRCs than with other cartridges?
 
I'm wondering if you have a slight ring right at the shoulder junction that creates a slight bulge and your die irons it out when you run it through your sizer.
Could have been caused by the reamer when it was chambered.
 
This may just be a perceived problem but I've never seen this before. I had 50 rounds of Lapua brass with two firings and decided it was time to anneal with AMP Aztec. Everything went fine with the annealing process but when I full length resized, I noticed it was just a little more difficult than usual. I say a little bit because the die has always seemed to be very tight to me (Redding Type-S Full Length Bushing Die). Anyway, my die is set for .002 setback and the first few I did bumped the shoulder back .004-.005. I suppose this could be due to lack of spring-back after annealing? I adjusted the die for .002 and continued resizing. I noticed every case has a thin shiny ring around the case at the shoulder junction. I measured the area and it was the same as that of a resized case that had not yet been annealed. I other thing I noticed was that the shoulder junction is now very sharp where prior to annealing it was more rounded. If you drag your fingernail down the shoulder you can feel it slightly catch at the junction. Is this normal? Almost makes me wish I hadn't annealed!

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You are definitely sizing in that area this is obvious due to the shiny ring, although I don't believe it is a problem it might be the result of a problem while cutting the chamber. the annealing has not caused this annealing will increase your shoulder setback due to not springing back as you mentioned though
 
I'm wondering if you have a slight ring right at the shoulder junction that creates a slight bulge and your die irons it out when you run it through your sizer.
Could have been caused by the reamer when it was chambered.
When I ran the new brass through the sizing die for the first time it took much more force than it should. I actually had to back out on some, re-lube, and start over. This is before they were even fired. There was no shiny ring at the shoulder junction at this point.

After the first firing I did not anneal and resizing was still difficult. Again, no shiny ring.

After the second firing I annealed before resizing. Resizing was again as difficult as ever and this time the ring appeared and you can tell the shoulder is sharper than after the previous resizings.

All this leads me to believe the issue is with the die.....or possibly the brass.
 
How much did your new brass grow (headspace/base) after firing? How far off the shell holder to resize
New brass was just as difficult to resize as once fired. Sizes were fine after first firing and the shoulder junction was not being sized. There was no more growth after the second firing than there was from the first firing. Annealing did not change the diameter at the shoulder yet I got the ring as if that area was being resized?

I just resized a twice fired case that has not been annealed and got the same shiny ring with the sharper shoulder...........Redding said to send it in. The cases shouldn't be that difficult to resize. Why didn't this happen after the first firing?
 
This may just be a perceived problem but I've never seen this before. I had 50 rounds of Lapua brass with two firings and decided it was time to anneal with AMP Aztec. Everything went fine with the annealing process but when I full length resized, I noticed it was just a little more difficult than usual. I say a little bit because the die has always seemed to be very tight to me (Redding Type-S Full Length Bushing Die). Anyway, my die is set for .002 setback and the first few I did bumped the shoulder back .004-.005. I suppose this could be due to lack of spring-back after annealing? I adjusted the die for .002 and continued resizing. I noticed every case has a thin shiny ring around the case at the shoulder junction. I measured the area and it was the same as that of a resized case that had not yet been annealed. I other thing I noticed was that the shoulder junction is now very sharp where prior to annealing it was more rounded. If you drag your fingernail down the shoulder you can feel it slightly catch at the junction. Is this normal? Almost makes me wish I hadn't annealed!

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All perfectly normal. You are GTG
 
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