My solution allows the shooter to also quantify bullets' effectiveness.
1. Go to hardware store and buy the least expensive duct tape available.
2. Go to your public library, or anywhere that has freebie magazines available.
3. Collect magazines in lots of 12-inch thickness. Acquire as many lots of 12 inches as you want. I personally prefer New Yorker because that pretty much useless waste of trees is published weekly. My library has bazillions.
4. Duct tape 12 inches of magazines into one solid target-backstop. I use one vertical and one horizontal layer of tape.
5. Go to wherever you shoot. If you prefer to place the target on a makeshift pedestal to rais it from ground level, do it when you place the target at the range desired.
6. Shoot. Target need be dry.
7. To reclaim lead, disassemble your target. If you want to examine "wound channel" and penetration, do so.
8. To compare muzzleloading bullets' performance with known "performer" as I do, just shoot your "control" into the same medium one group of three or five shots. My control is Barnes Triple Shock 150-grain bullet at chronographed 2900 fps [give or take] from Weatherby Vanguard 30-06. Once I had my control, I have no further need to retest.
9. FYI: No bullet ever tested - my control; .72-caliber 775-grain 30:1 conical; 45-70 420-grain WW+2 @ 1750 fps chronographed; 45-70 420-grain WW+2 @ 1750 chronographed and heat treated - has penetrated more than ≈ 6.5 inches of dry New Yorkers. My testing occurred at 15 yards.
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Were I to hunt cape buffalo with a muzzleloader, I would upgrade my control to a proven performer on that species. If necessary, I would increase my target thickness in 12-inch increments.
Hope this helps.
