It's ALL bad! I'll have my grandmother in Des Moines come by and pick it up to get it off your hands!
Seriously, as long as the brass is not corroded you should be fine. The other catch will be how out of spec it is from being fired in an MG. Depending how on the headspace when fired, you may have some brass that you just cant squeeze back with resizing. While Im not using WWII brass, the majority of mine is from the early 50's and Ive had no problems.
Also, be carefull of buying pulled bullets. If there pulled with a collet puller, they may be out of round and require resizing or you to go thru and check each one for roundness. If theyve been pulled buy using air, you are good to go. ALWAYS ask before you buy 50 bullets - the "deal" may not be that good. You can look at the bullets and see if they have collet marks.
Other than the joy of reloading and self reliance, I fine the talon ball to be cheaper than reloading depending on the deal I get. I may save 10-20 cents reloading but the ball shoots so well in my AR50 that thats what I mostly shoot.