10GA FH info.Fed factory hollowbase slug is .025" smaller than
10ga bore. I bumped it up to the .775" size, by expanding
hollow base. With 7383 that gave another 150 fps.Fast starting
shotgun powders expand base better than much slower 7383.
The Federal factory load has 120gr of wads/seals about 1.4"
long. Better to replace with much more slower powder,
getting better velocity, still at low shotgun pressures.Ed