Palmer,

Are we talking about women or double rifles now?
Very funny - it made me have a good laugh this morning anyway.

Firstly, as 1888 says, seating the bullet deeper can / DOES cause
an increase in pressure so to those who reload - beware !

Re confusion and complication - I had the same problem once when
trying to get a gun to shoot when I was new to all this - I changed more
than one thing / component and eneded up over 2 weekends totally confusing myself
as I didn't know which change had caused the improvement !!!
It was a 450/400.

I ended up going back to the starting load and bingo, got it very quickly.

I THINK the gun I have been talking about is a 450/400 3 1/4" Lancaster Sidelock
Ejector that now belongs to a friend in the US who then went to Africa and shot an
Elephant, Buffalo and Lion. Obviously the loads I gave him were correct !!!
He was happy.

500 Nitro