Not a springer, but:
I finally got around to working on Mrs Bum's Gunpower edge today. Its a budget 10m target rifle based around the Stealth, and I can tell you its an awful lot better than that sounds! I had it at the badge and it performed very well.
Thus far I had fitted baffles and ting to quieten the thing down for garden use, but one thing that was a worry was the hammer, as the cap'n pointed out, its steel and runs in an aluminium tube! Every time I shot it I had a mental image of bits of swarf building up inside.
Today it came apart, I cut some grooves into it, made some suitable rings, glued them in place and turned them down to fit the tube. It now moves very smoothly up and down with no hint of the graunchy feel you got with steel againt ally.
Consistency is still excellent and power is only fractionally down. The next project is the reg, see If I can't get more out of the little red beastie!