Hi guys I just purchased a Fastfire iii for my Remington 870 Turkey/Predator Model. I was wondering what mount you guys would use. I also wanted to know if I would be gaining anything by going to the speed bead mount? I had one last question I see that when thay advertise this optic that is states it comes with a CR-2032 but my fastfire iii takes a smaller battery, and aslo noticed that it takes a second or two for the dot to appear in the glass when turned on, is this normal? because the dot was very hard to find when the optic was not on the gun. Sorry for all the questions and THANKS!!!!!!
I have a fastfire III that I just purchased this February and put it on my Rem 870 Super Mag with a B-square mount. The mount is rock solid and also still allows you to see your original sights on your gun for extra insurance that I hope I will never have to use. As far as the dot being hard to find, it is sort of hard to find when not mounted. The dimness may be due to the brightness of your environment. When you first click it on it is on auto adjust, next click is bright, third click is medium and last click is dim for really dark conditions. Haven't messed with the battery yet other than putting it in the sight. I really like the sight and mount. Just my two cents. Hope this helps.
(http://i1097.photobucket.com/albums/g346/mrichardson06/8f68a306-1e4d-4959-891a-c613973aa46f_zps61ec6709.jpg) (http://s1097.photobucket.com/user/mrichardson06/media/8f68a306-1e4d-4959-891a-c613973aa46f_zps61ec6709.jpg.html)
I went with this one on my 870. You can still see the bead and it has a little more aesthically pleasing look to it IMO I was going to go with the BSquare but see no real difference and this one looks better and costs a lot less. This was a Barska mount and I got it from optics planet. It has a tactical scope mount, so I am not sure that the scope you are talking about will fit right into the slots provided.
I typically don't go the cheaper rout on my gear but figured at half the price of the Bsquare and the fact it looks better it worked for me. Assembly is not that hard at all. Pop your pins out of the 870 and re-insert the provided hardware. Just tighten the allen head bolt that attaches into the drilled and tapped mount.
The BSQUARE mount is tried and true and I have yet to find a bad review on it. I was in the market to buy it just didnt want the bid bulky looking mount on my gun.