CDM Gear MTRS Pro Series Light Mount with 3-Slot Side Rail, Compatible with Mossberg 590 Shockwave 12 or 20 Ga

I like the ease of installation and it fits perfect. I recommend a 45° offset rail mount to provide clearance on the pump handle action. Choice of mount angle and light will affect the fit with shorter barrels.

What a pleasant surprise this one was. I was about to buy the GGG brand one, but read about some flex/durability issues. I stumbled across this while browsing Amazon, and at first I thought it was a UTG/Chinese junk part. Nope. Texas company who stands by their gear, and it installed quick and easy, and does a great job of holding a light and acting as a sling mount both. And its low profile enough to not look stupid and bulky. Perfect accessory to finish off my 590 SBS. Thanks guys. Great product.

Very solid, great price. Fits pet

Probably the best product you will find to mount things onto a shockwave. Install was easy and only took a min. Removed one star just because the pain of having to place a little rubber sticker inside for it to fit right, and the sticker not being sticky enough to stick while you put it together. Doesn’t seem to interfere with the action.

This product worked as advertised. I watched a simple video instruction and it worked like a charm. I would recommend this product to everyone who is a "do-it-yourself" kind of person. Manufactured from aircraft grade aluminum and hard coat anodized it is a superior mounting solution for those with limited space mounting requirements. One tool for one bolt is all that is needed to attach and remove the clamp. Fits Mossberg 590 Shockwave 20 gauge.

Seems like a solid product. You can tell that whoever designed this knew what people wanted for an accessory mount. My only gripes are the finish color and the very small interference between the forearm slide and the rail that came with the light I chose. I'm guessing others could have the same problem even if they fit a different light... since the fit/size of a rail will be close no matter what. The finish color or shade does not match the 590S Shockwave barrel, magazine tube, forearm slide or magazine cap. I think that's something that should be considered in any future design revisions. Easy improvement to the aesthetic. The forearm slide interference (again, from a light/rail add-on that i chose to go with) does not prevent the cycling of shells at all, but it does leave a very very small dent. I'm not particularly worried about it, but that could bother some people. As you can see in the pictures I include with this review, I went with a TLR-1 HL from Streamlight.

Way too big, does not fit on 20 gauge -- I wonder if they sent the 12 gauge version, but the packaging says its for the 20

The maker of this product, CDM Gear, is now aware of this issue, and intends to amend the item description. This mount, despite how VERY well made it is, will NOT fit the 12g 590 Shockwave variant with Walnut furniture, the “590 Nightstick.” The gap in front of the Nightstick’s pump handle, where it is intended to be installed, by design, is apparently too narrow on the 590 Nightstick. Such a shame, as it appears to be an OUTSTANDING mount for the “polymer furniture” version of the Shockwave. I still gave it 5 stars, despite it not working for me… that’s how nice it is. And CDM/ Amazon was nice about it, and allowed the return.