Remington 870, just installed a Surefire forend. Everything went fine, until I began function testing it. Usually when I rack the slide back and forth, it goes perfect, however if I tilt the shotgun over to the right while doing so, the bolt locks about halfway and won't budge forward anymore. It will go back and forward up to the  point of failure, but it won't go towards the barrel and lock up. The slide is not binding on the barrel or anything like that, but something is definitely wrong. If I "tap" the shotgun to on the left side rather sharply, it will then go forward into battery. The bolt face is about 1/8 to 1/16th of an inch away from the top portion of the barrel in the receiver when the stoppage occurs.

I've looked at the bolt and can't find anything that indicates a bind.


Anybody know the answer?

Sounds like something you did when installing the light to the action bar assembly is causing it to bind somewhere...action bars twisted just a bit maybe? I'd disassemble and reassemble it paying close attention to keeping everything as straight and square as possible then try it again.

Fixed. Thanks!

Well, dammit...WTF was it?