Flattened Primers

[Coyotegunner]

I reload for 3 different 22-250s I own.Plus a grip of others.I have a older redo of a mexican contract mauser with a wonderfully accurate barrel on it.
The mauser has always seemed to flatten primers a little,even with mild loads.To stop it,I reload 15% lower than any powder manufacturers info.I have had the barrel cut and rechambered,tried 3 manufacturers of brass,5 different bullet types.I have been stumped.Called tech service at 2 powder companies and 3 bullet companies.No ideas.

To the point.I had purchased 2) bricks of Winchester LR primers.They work fine in any gun I load them in including the 2 other 22-250s.I ran into a guy named John at AVGC.He looks like Santa Claus.He says try CCI 200primers,they are made of harder metal maybe,and they are larger.He was right.They go in the pockets with more effort and they did not flatten.My old rifle is back to shooting normal loads.Merry Christmas

Spoke with John and thanked him.Seems my old barrel may be a little tight,causing just enough pressure to back out and flatten primers.

Hope this helps at least 1 person that has ran into this.I love my Winchester primers,but for this gun I have to buy CCI

[sacto929]

OP,

Thanks for the post! I'm glad that I'm not this only one having this issue. My 03A3 does the same thing with loads that would be considered just a hair above minimum. No signs of case bulging, etc., but the WLR primers flatten. I've been using HXP cases with H4895 and 175 SMK. Mid-range loads (hotter than what I did) done by my BIL using my components, except with CCI primers showed no signs at all.

I guess it's all a part of finding what works in a particular gun....

[smoothy8500]

I had a rifle with a somewhat long headspace (closed on NO GO, but not a FIELD). I found out because the primers would appear flattened with factory loads. It seems the primer backed out upon firing, then the case would move back a couple thousanths of an inch squeezing the primer. Or as sacto929 posted, Win primers also appear more flat than CCI in my reloads. Since you've had your chamber re-done, it's probably not headspace issue.

[wtkaiser]

I had some very flattened primers in some .38s, lightly loaded of all things! I wrote to Speer about them, and I received a letter back saying that flattened primers, in and of themselves, are not a reliable indicator of high pressure. There were too many other variables that might cause them.
This was back when I still had some hair on my head, so it was quite a while ago, and I forget which brand of primers I used, unfortunately. For the past umpty years, I have been using Winchester LP and LR primers, and have had zero problems with them. But I am not above using CCIs if I'm in a inch.