Just got my FF3 mounted on my Glock 40 MOS 10mm lastnight.  Mounting was dead easy.  Took it to the range today and the groups I shot at 30 yards were amazing.

I absolutely love my Glock 40.

Hello fellow 10mm owners and shooters! 
I took my Glock 40 Gen4 M.O.S. with factory sights, out to our range for the second time today, fired HSM 200 grain FmJ, Underwood 155 grain FMJ, Liberty Civil Defence 60 grain.  Everything feed and fired just great, no hangup at all.  After a pile of empty brass and a very dirty pistol I continue to be amazed at how accurate and powerful this caliber is. 
All out a fine day!