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

Great holder! Easy install. Firm grip on shells. Looks great.

This product is fantastic! The material is incredibly strong, yet the gun still feels surprisingly light. Installing the slide was a breeze; it fit my 535 perfectly. To top it off, the appearance it gives my gun is incredibly sharp.

Monstrum is the finishing touch! Bird head grip, factory head shield, and now the Monstrum rail and side saddle. NICE! Good price with the $5 discount code and easy installation. This will last for years. I’m a very satisfied customer!

I have a Mossberg 500 ATP with an H code series number which indicates it was made in 1983. I didn’t look at it prior to ordering this side saddle. Unfortunately my receiver is not drilled or tapped for mounting this product. The product is well made and has all the appropriate screws to mount on a drilled and tapped receiver. I was disappointed it didn’t fit. I returned it to Amazon with no problems, and bought a sling which holds 15 shells. Great product buu check your 500 receiver for screws before you order. This does not fit all 500’s.

The saddle looks good and the fitment is perfect. The shell holders are tight and shave the plastic off the shells when loading. Questionable durability on the shell holders. The pic rail is good quality for the price , hold 6 shelms neat and snug.

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.

Works great,Easy install and fit was good.