I have Speedfeed fore ends and a Surefire, all work well with the Mesa Six Shot shell caddy. FWIW, someone above said the Surfire is heavy and hard to grip. I agree it is heavy, but I find it easy to grip and use. I have had mine on my HD shotgun for about eight years now. IMHO it is the ONLY option for adding a light to your 870. My setup (pic later):
Remington 870 Police Magnum (was a PD trade in, was an animal control units gun in VB)
181/2" IC barrel. I have polished the bore and chamber till it looks like chrome....easy to clean, will eject anything, tight and perfectly symmetrical patterns.
Big Dot tritium sight epoxied on over the original bead.
Vang Comp +2 two mag extension with high visibility follower and Wolffe spring. Polished the mag tube also.
Mesa Tactical Urbino stock with recoil pad. Felt recoil is milder than a 20 guage.
Mesa Tactical six shot shell caddy
Surefire fore end light. I replaced incandescent bulb with an LED a couple of years ago.
I cannot guess how many rounds I have fired since I got it, well over 2000 buckshot and many more birdshot and slugs.. Not as much as many shoot in matches, but this is my HD / SHTF shotgun. It functions flawlessly and patterns very well with Federal and Remington 00 buck and slugs.