Thanks for the kudos about my post concerning felt wads.
Yep, I too use a 3/8" wad punch to make .36 caliber wads. Should also work fine for any .37-caliber rifles (.38-55, .375 H&H, .378 Weatherby, etc.).
The 7/16th punch is too small for the .44 cap and balls, which are actually closer to .45 caliber. However, it creates a wad just right for the .44/40, .44 Special, .444 Marlin, .44 Magnum, etc.
I had to break down and buy a true .45-caliber wad cutter from Buffalo Arms. Cost $18 at the time (now it's about $20) but considering that the darn thing never wears out if properly treated, it pays for itself over the cost of buying premade wads.
The 1/2 punch is just right for .50 caliber. I use it for wads in my .50 Hawken.
I use the end of a 12-inch log, about 8 inches in diameter. Found it at the thrift store, with some cutesy-poo bear decorated on it, for $1. No pine trees here in the desert, Actually, the end of a piece of 4X4 would have worked as well to punch against.
I improved my short log by epoxying a layer of that hard, plastic cutting material on the end. It's used on cutting, sewing and framing tables, wherever there's a lot of cutting. A plastic cutting board for kichen use should be work too, glued to the end of your log or 4X4.
Cut the plastic to fit just to the edge of the wood. Glue it, so your wad cutter get dull hitting nails or tacks.