I would think TVM would use the 7/8 x 42 x .45 GMB if you requested it... Did you know that with a 3fg black powder charge of 75 grains you will realize 2000 fps, and 330+ Ft. lb. of energy at 100 yards... More then adequate for deer size game... Your drop will be in the 6 to 7 inch neighborhood at 100 yards...
At 50 yards you should realize, 600+ FPE, and a 1 to 1+ inch drop with the same charge... This is using a .445 patched round ball, and the .45 GMB seems to like these from my experience... Also, they're not hard to load, or reload after a shot...
I like my .45 GMB... I've taken deer with both the 36" percussion, and 42" flintlock, (both shots under 75 yards), and both with a 65 grain load of 3fg Goex... Both shots went right through the lungs and they went right down... I would have taken the shots out to 100 yards if I would have had to...
I feel confidant hunting with my .45's... :thumbsup: With all caliber's,,, bullet placement is everything... I am building a new .54 hunting rifle for this season but if I don't get it done I'll take one of my .45's...