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.

It installed very easy and fits perfectly. It doesn't cover the safety or go past the chamber over the barrel on a Mossberg 590 12 ga shot gun. The 6 shells are held in tightly yet I didn't have any problem removing the 6 shells and reloading.The bad reviews are not accurate.I read all the negative reviews and was concerned after I purchased the item, but I figured I would give it a shot (Pun intended).I thought if it doesn't fit I will return it but it can't hurt to try it since there are so many good reviews.It goes on so easily I was pleasantly satisfied. It took me 5 minutes to install and I didn't need longer screws or any "LOCK TIGHT" to install it and snug it down securely. All the screws and the allen wrench came in the box that I used to install it.I will say though "WHEN ORDERING MAKE SURE YOU CLICK ON THE 12 GA OR 20 GA MODEL BEFORE COMPLETING THE PURCHASE".I think that is what throws people off to get a negative review because they receive the wrong caliber shell holder (12 ga 6 shell holder or a 20 ga 7 shell holder, that also threw me off in the description compared to the picture provided they have to describe the item on the Amazon page). And they do not realize it until they receive it and some people after receiving it. I ordered the product then had to cancel because it was set on the 20 ga, It was easy to cancel that order and reorder the 12 ga model.I don't have a picture but it fit perfectly on my Mossberg 590 12ga as pictured on other good reviews..Sturdy metal and polymer material, built to last and take some good hard working abuse !!!I AM VERY HAPPY WITH THIS ITEM , IT IS JUST WHAT I WANTED !!I will order again if I get another Mossberg 500, 590 or 590A1 12 ga.

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.