Ok, took me almost a year to find time to wring 'em out formally, but here it is: Ruger KMK10 AT 100 YDS
5.5 TO 6 inch groups with Aguila Super Sniper Subsonics
2.5 TO 3 INCH GROUPS WITH AGUILA SUPER EXTRA
SSS showed evidence of keyholing, but, with that performance WHO CARES!
So to answer...