Mike Casselton
Interesting observation from today's shooting
Thursday, March 22, 2018, 14:00

I finally got out to the range today with a brace of pistols.
The first one I shot was the 41 mag Gary refinished for me.
I was shooting a 210gr XTP over a max load of H-110.
The first cylinder full seemed to have excessive recoil with a lot of barrel rise.
When I pushed the cases out of the cylinder I noticed a lot of soot and what appeared to be oil.
Oh,crap! It was oil. I had forgotten to run a couple of dry patches through it.

Cleaned it out and loaded it back up. Shot six more and it felt like it was completely normal again.
The second set of cases came out clean. I inspected the cases further and also noticed that the primers on the first set were flattened almost completely. The second set were normal.

I know someone will ask so here goes.
All cases are from the same lot. Primers, bullets and powder also the same lot.
All cases were loaded the same day and during identical atmospheric conditions.
(I used to run an ammunition facility, so I actually know what I'm doing)

So, why am I posting this?

Well, after reading Scotty's information about cartridge thrust, I have to believe the oil in the chamber caused the recoil condition and also the severely flattened primers. I have no other explanation for this happening. I know the powder measure didn't throw the wrong charge. I check it before and after. My scale is correct.
The only odd thing is oil in the cylinder. Once it was removed the problem went away.

Just more food for thought