17lbs for competition only and 18lbs for carry for a hammer spring and stock SIG recoil spring. Also check out
Langdon Tactical I have LTT 17lb competition hammer spring in my 220ST-EL. When ever he starts accepting pistols again I'll be sending my my 220ST. I have a level 2 LTT trigger job on my 2 tone 220 with a 18lb hammer spring which has a SA pull of 3.75lbs and a DA of 7.75lbs. The 18lb springs that LTT sales are the ones SIG uses in the DAO 220s.