I used an online calculater it says at 42 gr I should get 1,333 rounds :-) does this sound right to you guys?

166 per pound...1333 per eight...

8#'s x's 7000grains divided by 42 grains =1333

what about that 2% that he spilt on the bench and floor.

[unit price]/[weight in grains] X [X (the unknown)]/[grains consumed]
This will put a dollar mount on the amount of powder consumed.

[charge weight]X[units loaded]/7000 = # of loads/1 lb. can

Clear as mud?

Yes it's easy to figure the cost of reloading until you actually start doing it !.

Funny how Murphy's law plays a role in those equations , Isn't it !.

Messed up case primer didn't seat powder spilled out , rest assure of two things .

Your going to get quality Ammo at a Superior discount and if anything goes wrong YOU

know who's too Blame !!.

Dont forget the 14 grns you have left over.