Monstrum Side Saddle Shell Holder with Picatinny Rail Mount for Mossberg 500/590/Shockwave Series Shotguns

Wonderful, perfect fit, solid and snug, and perfect mount for my rear ghost ring to give a great sight picture on my front fiberoptic, 10/10 highly recommend

Amazingly, this product does exactly what it says it will do. First of all, let me comment on the ease of installation. Four long screws take the place of the filler screws on the top of the receiver. This item is in 2 pieces. The Pic rail is one part and the shell holder the second part. The shell holder in held in place by the 4 screws that hold the Pic rail to the receiver. A very secure mount. One thing that is different than the picture of the item is that the bevels are actually beveled down. Shown in the ad the bevels are up. I wondered about that but the one I received had the bevels on the bottom side. As they should be. Love the item and although I would have liked to see it less expensive, it turned out to be well worth the money. I have pictured it mounted on my 590 but they make them for a bunch of tactical shotguns.

For a home defense shotgun this is a must-have accessory. It enables you to carry extra ammo while also providing a mounting platform for powered optics, such as a red dot. Most shotguns have limited ammo capacity, and you're not going to have time to grab extra shells if you hear a bump in the night. Having those extra shells already mounted to the gun gives you the opportunity to reload, which could be a lifesaver in a hostile encounter.This product surprised me with its quality and price point. It works great, fits great, holds up well under heavy use, and looks awesome to boot. Buy one - you won't be disappointed.It will fit the Mossberg 590 shockwave. Be sure to order the correct version - there are options for 12ga and 20ga. In order to install this product your shotgun must have a drilled & tapped receiver - in other words, little flat-head screws running down the top centerline of the gun.You may consider installing a larger front sight, because this product adds a little extra height to the receiver, and may make it difficult to aim with a standard bead... or just get a red dot and install it on the rail. Also consider using loctite when you install to prevent the screws from loosening under strain from recoil.

Had a little bit of difficulty getting the correct product sent to me two times in a row where a different product was sent but on the packaging the label was correct so it was being mislabeled at factory or distribution center for some reason.The product is good, but not great for a couple of reasons:1. This is a two-piece design and it would be much better if it was one piece so that the picatinny rail was not so high off of the shotgun which automatically puts whatever optic you want on your shotgun higher than you truly need it.2. I got both versions of this six shell side saddle, one for my 20 gauge and one for my 12 gauge. The one for the 20 gauge required me to cut down my foregrip because it was sliding onto my receiver about 2 in and was hitting the side saddle. This particular 20 gauge Model was the pistol grip Persuader model that had the 9-in stock length foregrip which was entirely too long to fit this accessory so I modified it.3. Personally I think there's too much play in the rail movement for the screw holes. You get offset or misalign the rail in relation to the barrel quite a bit to throw any optic you put on it out of whack. Most Optics only have so much adjustability and one degree out of absolute parallel is still 1 degree which put you way off Target.4. All six Shell Holders do not hold the shells evenly. The two outside ones are far looser than the four on the inside. That's just annoying. I like the brass facing down so when you flip the gun upside down it's easier for loading but I'm hoping that they don't fall out while shootingI ordered some other parts from this company so I'll see how the quality is on those when I get them.It did come with the correct length screws so that was a plus.

First, the product is well made. It looks great on the gun and works well. Everything I had hoped for.Purchased it for a 930 tactical, understanding that there could be fitment issues. Was very pleased to find that these were minor and easily addressed with a razor saw and a small file.The screw holes were dead on, no need to start the screws themselves at any sort of a slight angle or wiggle them as one often finds in bolt on products for anything. Screw length did not need to be trimmed, as I have read some people have needed to do when using other products marketed for the pump versions on the semi-auto. Torx head screws are an excellent touch; thanks Monstrum!Fore end needs to be notched approximately 1/4" x 1" to allow the unit to be mounted. A very easy process, as you can use the unit itself for a pattern to scribe your cut line by temporarily attaching it with a couple of screws.After that, clean up and round the corners with a file, and it will look like it came from Mossberg that way.

Good quality materials all around and easy to install on a Mossberg 590. The rail and backing are quality aluminum and the side saddle that grips the shells is high grade plastic. The openings are big enough to easily manipulate the shells but hold them tight so they don't come loose.

Fits Mossberg 500. Seems to be a good value.