Well I changed all the powder I had in the 500 shells because the powder I was using said my 275gr bullets would go 2034fps so fired a couple thru my conagraph to find out how fast they were going. This is what I got 1293fps. So now I get a little slower fps but it is a steady fps. I sighted it in with the 400gr bullets going 1600 fps at 100 yards and the three shot group was 2.5". I have a 2X scope on it. I have some powder on order that will go faster in my 500. When I get it I'll load the 400gr bullets a little faster. I don't shoot lead bullets in this gun. Don't want leaded barrel. The 350's will do 1700fps thats not to bad.
The 325's do a little over 1800 fps