That 12 gauge load would concern me.
Hodgdon lists that load at 20.5 Gr. and that's with a W209.
They publish nothing with the Remington primer, significantly even with Remington shells. Rem 209 is a very mild primer.
The Windjammer wad has about the poorest gas sealing of any wad available.
End result is a very dirty load at best, at worst you may be flirting with a 'secondary explosion' scenario.
It works like this:
The weather gets a little chilly, the Remington primer sort of lights off the 800X which has a reputation of being difficult to ignite anyway. It kicks the shot charge down barrel a short distance and the fire which wasn't too intense in the first place goes almost, but not quite, out. Then the pressure builds up from the slowed ejecta, the powder finally gets to it's ideal combustion pressure... and... Kaboom.
I would at the very least use a W209 and the published charge.
