MonstrumSide Saddle 12 Gauge Shotgun Shell Holder | Compatible with Maverick 88/Mossberg 500/590/Shockwave Series Shotguns

Ordered this item for, my recent purchase of my Mossberg Maverick 88. Bought this as the combo package with the two barrels, and wanted to stay at a budget point. With that said, I wanted to accessorize it, but not spend a ton of money.I bought the Monstrum side saddle, and didn't have any preconceived notions as to how good it was. When it arrived, I was pleasantly surprised at how solid it was and how nicely built. I honestly just expected a piece of plastic. It has a great metal backing plate.It was also designed perfectly, and lined up exactly with the holes for installation. Easy to read and understand instructions made installation a breeze.After a day at the range, it worked perfectly. Upon cleaning the firearm post shooting, I did realize it was a little loose. That did not surprise me, as the force of 100 rounds through a 12 ga shotgun would knock anything loose. I also never used any loctite on installation. ( hindsight)When I tried to tighten it up, I think I added a little too much force, and probably stripped one of the mounting screws....my fault, not the product.I reached out to Monstrum, to buy replacement screw/pin, so I could remedy this issue. The gentleman asked for a copy of my order ( gave the Amazon screenshot picture) and my address. He never asked for any kind of payment at all.Two days later the parts showed up, and perfect delivery. Outstanding customer service and standing behind their products. I wish all companies were this good. Highly recommend their products.

Taking the ejector screw (slotted flat head flat head) out of the inside of the gun was harder than implied. The rest was actually pretty simple. The replacement ejector screw (0.25" longer) had a Phillips cross. It should have been a hex to fit the larger allen wrench included in the kit.The simple instructions on the side of the box should be replaced by an expanded set of instructions on a piece of paper sent inside the box. There would be room for details like TIGHTEN the new ejector screw and get a 9/32" socket to tighten down the nut holding the shell holder to the gun and be sure to put one of the included washers under the nut.I was particularly happy when I wrote MONSTRUM for info about complaints on Amazon in the 1-star area. I received feedback that those were based on an early release addressed a while back. The factory rep (Gerald - GOOD guy!) was correct. This works like a champ and when installed with a full 6-shell load on my Mossberg 500 Tactical Breacher makes a bad-boy gun look like something Satin might carry.

It's made of plastic for the shell holders and the backing is metal. Shells fit into them nice and snug, but not too snug to where it may snag.My only complaint is that it covers the serial number and it was not compatible with my original forend. I had to buy the Magpul forend for it to work properly.

This side saddle is a great addition to my Mossberg Maverick. The storage of an extra 6 rounds readily available is great. It fits perfectly and only took about 3 mins to install. I did use loctite on the screws to ensure they stay in place.

The saddle itself seems to be decently made. Hold shells as it should. The included hardware is garbage though, did not really work with my Mossberg 500. The ejector screw thread pitch is standard and the hardware included is metric. So the m4 screws won't work and you will strip it. I'm trying to figure out the thread for the standard Mossberg 500 ejector screw so I can just buy a better screw online. You can make it work by flipping the ejector screw around so the head is on the outside of the receiver and you have just enough threads to tighten the saddle down. But I'm sure this won't last after a few round will loosen. Once I find a good replacement screw that's a little longer I'll update here.

Fits and functions as intended, could use more detailed instructions though

Trigger group pin was too short, was far from flush. The screw for the receiver was the wrong thread. The shell holder itself was decent, couldn’t use it unfortunately

works well and fits well. shells fit tight. no complaints. all needed hardware included.