In my .62 caliber Fusil de Chasse I use 65 gr of 2f. Over the powder I use a wad of wasp nest (about the size of a .62 caliber round ball or slightly bigger). Then I use same measure for 65 gr of #6 shot. Another wad of wasp nest goes on top of the shot. Both wads are tamped down just firmly enough to keep everything together. I prime with the same powder. I've used 3f also and can't tell much difference in the woods.
This combination patterns well out to about 25 yards and I haven't lost a squirrel yet. Around 30 yards the shot spreads too much leaving holes in the pattern. I stalk hunt for close shots and sometimes have to pass on the squirrels out of range.
I've tried a bunch of different wads including newspaper, brown paper, flannel, leather, felt, tow, jute, cardboard, leaves and grass. The cards/wads mentioned in the previous posts work well and if they work for you there's no reason to do different. I use wasp nest because it's supposedly a historically correct method, it's cheap and readily available and easy to use. I didn't mention this to start another debate, just passing along my method.
I think the load combination you are using will work just fine. I like the tin can (pop can) test. It's about the same size as a squirrel and is a reactive target. This keeps practice fun and realistic.
