If i end up getting one of those $265.00 Rem 870 Police pumps i'm almost definitely gonna take the Fastfire off my P7 and put it on there.
They sell a super slick stock spacer mount for it. I think the HUD will line up a lot more naturally with a long gun.
It looks pretty badass on my AR with a riser mount. Gotta remember to take some pix next time i'm swapping around optics and messing with the AR config.
With the carry handle rail mount i can have 3x day/night targetting systems at once. Laserlyte red laser, tritium iron sights and the Fastfire. The PS-55 looks much cooler though, so i just leave that on there. It works great anyway.