16.5 is the low end at 1150 fps
17.8gr at 1200 fps
18.7gr at 1250 fps - at the high end.
But what I think is interesting is between 1150 fps and 1200 fps / the difference of 50 fps ..requires 1.3 grains of powder. At the upper end the 50 fps between 1200 and 1250 fps only requires 0.9 grain....so that tells you something about how much powder it takes to get a good burn ...and consistent velocity.
I'd probably suggest you start with a box of test shells: ( mark the bags / use sandwich bags or something )...
5 shells in the 16.5 range ...at 1150 fps.
5 shells in the 1200 fps shell.
5 shells in the 1250 fps shell.
and interpolating a little - some at 18.2gr for a shell that is around 1225 fps.
Run a bore snake thru the gun so its clean - shoot the 5 shells ...and check the bore to see how dirty it is. After you shoot 5 - run the bore snake thru the bore again and clean it out ...and note the difference. My hunch is, at the low end, you might find its pretty dirty with a lot of unburnt powder or junk in the bore. At the upper end, I suspect you'll find its cleaner. Personally, I like it pretty clean.
Then it comes down to recoil ...I don't know what gun you're shooting and if its a gas operated semi-auto it might not matter...but if its a fixed breech gun like a pump or an Over Under ...the difference in recoil between the 1150 fps ...and the 1250 fps is about 15%( if its a 7 1/2 lb gun ) ...and 15% is a lot, and its cumulative ...so as the day goes on, it'll tire you out a little...
Powder only makes up 2 or 3 cents of the cost of a $ 0.15 shell ..so using less powder, will save you a little money, but not a lot .....most of picking a load is how clean it is / what velocity you like to shoot / and how the recoil feels. Personally, I tend to load all of my 1 oz loads at around 1225 fps ...and almost exclusively with 8's. A shell of 1225 fps is more than I need for Skeet, but its fine for Trap ( even continental, or handicapped distances ) and its a good sporting clays load. At times in my shooting career - I've had hot ones, and mid range shells, and slower shells...but now I just shoot one 12ga shell for everything ...and don't worry about mixing them up / getting them in the wrong bag when I empty my vest, etc ....
and get out and have some fun with this stuff ....you're loading your own shells now man ....welcome to our end of the hobby !!
Last edited by BigJimP; June 3, 2011 at 02:34 PM.