FYI the US Border Patrol used this ammo until 2002 out their Beretta 96's. Their results with it in putting people down were quite spectacular.
http://findarticles.com/p/articles/mi_m0BQY/is_3_48/ai_82551648/pg_2/
Shooting Illustrated recently re-tested this round and it went 10 1/4" and expanded to .75
FYI in the same test they tested the Winchester 180gr PDX1 which went 10 3/4" and expanded to .83
It appears that Shooting illustrated is using perma-gel to test expansion and that is why the penetration numbers are less for both rounds than we commonly see.
http://www.shootingillustrated.com/tag/winchester/
The 155gr Silvertip is a darn good carry round in the .40S&W. Yes it's old tech but it's still VERY good even compared to the most advanced ammo currently availiable. FYI the silver tip ammo line was redesgined by Winchester to make it perform better and try and get out from under the bad cloud the FBI gave it when they needed a scape goat to cover up their own people's failures, bad training and bad tactics in Miami.
The reason alot of departments are dropping the 155gr 40S&W load is becasue it's are too hard on their guns and has too much recoil to be controlable by small and weak people. It dosen't have anything to do with terminal performance of the bullet. The Border Patrol specifically is having a hard time. For a while they went to training with 180's and carrying 155's on duty - and now they have gone entirely to 180's because of equipment maintenance cost.
Will