Well to be honest, when we had group shoots, after the men had their fun, we would load and supervise the children. Now I am talking some small kids. There were a few ten year old's and a couple twelve year old's, and they were not large kids. I watched them little guys with 70 grains of Pyrodex RS shooting roundball and begging for the chance to shoot again.
I would think 40 or 50 grains would not be too much in a traditional rifle. Load up 50 grains and shoot it off hand, without it being on your shoulder and see what kind of jump it makes. I shoot 50 in a Knight Wolverine inline and you'd hardly know you shot it. In fact a lady friend of mine was over one day and I was loading 70 grains of powder and a patched ball for her. She did not seem to mind that at all. And actually she had a lot of fun and did pretty good.
