CRL,

Congratulations!

A practice load that I have found works well in the .470 at 50 yards is 45.0 grains XMP5744 powder behind a 500 grain cast lead bullet (gas check not necessary) with F215 primers. No filler needed. Recoil is mild - it's about like a black powder 45-70 load.

If you want, you can substitute 400 grain .475" jacketed pistol bullets for the 500 grain lead, but the loads will shoot apart and high. Then you need to increase the powder charge until the bullets converge.

Have fun!