Does anyone have a good recipe for hardening small parts at home?
I would like to surface harden some SAA parts to  prolong the timing before wear changes things.

Royce,  An oldtimers trick for surface hardening steel and steel alloy mixes is to heat the parts with a propane torch to a dull red glow and quickly quench the part in oil. Ordinary 30 weight motor oil works fine, but you sure want to do the whole operation in the garage or outdoors because the quenching makes a lot of smoke and stink. The part MUST be heated evenly all over! You can repeat the operation a time or two as needed, but don't let the part heat to bright red or cherry red as this only serves to soften the steel.
Practice the procedure on a new nail which is high carbon content steel until you get the "feel" for the routine. The nail you harden makes a good test tool for surface hardness of you treated parts too. It's hard and if it won't scratch your treated gun parts, then you've got them fairly well hardened. This is in effect "case hardening". Hope this helps, and careful not to get burnt by the hot metal or oil!                         loose-round

Home heat treating, not a good idea!
I've been a tool maker for 10yrs, and know how hard it is to get the heat treatment right on a piece of steel. You have to know what kind of steel you have,is it heat treatable, whats the critical temp. of the steel,is it going to be too brittle after hardening,do you need to draw it back?
Low carbon steel can be surface hardened. I've used "cherry red", it's a green powder that the part is coated in,then heated. I've tried just using oil,it didn't work for me.
If you realy want to harden your gun parts, take them to a good gunsmith. The parts are going to warp, how much I don't know.