I also got one with defective side rails - SureFire Benelli M4 Shotgun Picatinny Rail System M80 for SureFire Laser sights flashlights

Although I've had this rail system for a few months, I just had an opportunity to mount it to my Benelli M4 a few days ago. Much to my disappointment, my Larue Offset Scout Light mount will NOT attach to either the right or left side rails (3:00 and 9:00 positions). Instead of using the $100+ Larue quick detach Offset Scout Light Mount like I have on all of my other Picatinny railed long guns, my only apparent option is to use the basic SureFire screw on cross-bolt mount that was originally supplied with the Scout Light.

To ascertain if this could be a Larue mount issue instead of a problem with the new SureFire rail system, I attached the Larue to the Picatinny rails mounted on several other rifles. The Larue mount fit fine on all of those in every possible mounting position. As I continued troubleshooting this problem, I also tried to mount three other identical Larue quick detach Scout Light mounts on this new SureFire Benelli M4 rail. Same results! The rail's 3:00 and 9:00 positions will not accept the Larue mount. It seems pretty apparent that the side rails on my brand new SureFire Benelli M4 rail system are NOT in spec.

I just discovered that another Optics Planet reviewer has also experienced the same issue as mine. His review was posted over one year ago. However, a more recent OP reviewer said that his rail system worked fine. I'm not sure what the explanation is, but I do know that this is not a typical example of the quality I've come to expect from SureFire over the years. I've always been very impressed by the overall quality of the SureFire product line, but this one has been a huge disappointment.

I'll use the Larue quick detach mount on another rifle, so it won't be wasted. The SureFire Scout Light's factory screw-on mount seems to be pretty secure on the rail in the 9:00 position, so I guess I'll just stick with that for now. It's been almost five months since I purchased the defective SureFire rail system, so I probably won't try to ask for a refund from OP or SureFire at this point. Both SureFire and Optics Planet have good reputations for customer service, but it's not worth the trouble of removing the Loctite'd screw-on mount, return shipping the rail, and having to get a different shotgun qualified for patrol duty while this one is without a light as the claim is being reviewed, etc.

I'm just very surprised and disappointed that this particular SureFire item didn't live up to their normal level of quality. Lesson learned: Install your new accessories as soon as you receive them to ensure that you didn't pay good money for a dud!