I've cast #1, #00 and #4 for my SxS caplock and yes, after the mold heats up a bit, it works fine. What I think could ake it more comfortable would be shortening the handle tangs couple cm back, so their ends would be all under the wood, not reaching to the end where they burn your hand after a while.
Also found out the casting is much more effective with a simple ladle, rather than pouring from the melter's valve.
Nail clipping pliers are great for cutting the sprew.