Prototyping a top rail / shell holder for 500 & 870 platforms

[bradsteen]

Hey all,

After my ridiculous shockwave build I found a 3D designer to help bring the idea of a top rail/shell holder to life. The idea is to enable carrying of spare shells across the top of the receiver and barrel instead of a traditional sidesaddle. This would be for Mossberg 500 and Remington 870 platforms equipped with a hi-mount pistol grip and AR style receiver extension where the stock or brace is in line with the top of the shotgun receiver.

The challenges I ran into with the experiment were (a) using a rail system and bolting on picatinny shell holders added a substantial amount of weight, and (b) height over bore for the sights was higher than ideal. I'm aiming for a solution where the shell holder is as low as possible, and any rails are above or adjacent to it. This should bring height over bore to roughly match that of an AR.

Just got the first prototype back. It's very early stages - we're working out mounting and stability of the system first, after which we will tackle placement of the shell carrier and rails. Will add more updates and photos as the project progresses.

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[Member 93125]

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[ilikegunspdx]

Hey all,

After my ridiculous shockwave build I found a 3D designer to help bring the idea of a top rail/shell holder to life. The idea is to enable carrying of spare shells across the top of the receiver and barrel instead of a traditional sidesaddle. This would be for Mossberg 500 and Remington 870 platforms equipped with a hi-mount pistol grip and AR style receiver extension where the stock or brace is in line with the top of the shotgun receiver.

The challenges I ran into with the experiment were (a) using a rail system and bolting on picatinny shell holders added a substantial amount of weight, and (b) height over bore for the sights was higher than ideal. I'm aiming for a solution where the shell holder is as low as possible, and any rails are above or adjacent to it. This should bring height over bore to roughly match that of an AR.

Just got the first prototype back. It's very early stages - we're working out mounting and stability of the system first, after which we will tackle placement of the shell carrier and rails. Will add more updates and photos as the project progresses.

View attachment 2003700 View attachment 2003701

I would much rather carry the shells in the magazine. No slow loading required. Similar to how a person wouldn't mount individual bullets to an AR when you can simply change mags. This 20 sec video explains it better than I can:

FullSizeRender.MOV

• ilikegunspdx
• Feb 4, 2024

 

[bradsteen]

I would much rather carry the shells in the magazine. No slow loading required. Similar to how a person wouldn't mount individual bullets to an AR when you can simply change mags. This 20 sec video explains it better than I can:

FullSizeRender.MOV

• ilikegunspdx
• Feb 4, 2024

Yeah, that's fine for those who have a mag-fed shotgun, but most aren't.

 

[Member 24198]

Won't the shells being on the top of the receiver get in the way of pointing the shotgun?

 

[ilikegunspdx]

For sport or hunting tube fed is just fine but why people still use tube fed tactical shotguns is beyond me. Few would choose a tactical rifle like an AR if it shot 6 shots then load one by one after that. Why settle for that in a tactical shotgun?

My semi auto mag fed Fe shoots a 20 round drum in 4 seconds. No way a tube fed can do that even using "continuous reload". And it takes just a second to load the next 10 round stick mag. Same rate of fire as AR (300 rpm) and same reload method. Instead of making really cumbersome storage solutions that bring up new drawbacks, why not solve the problems of low capacity and slow reload completely by using a reliable mag fed shotgun?

 

[bradsteen]

Won't the shells being on the top of the receiver get in the way of pointing the shotgun?

Nope, the plan is to have a pic rail and/or iron sights on top of the shells (those will come later, once we've ensured the mounting mechanism is solid). With a high mount grip that uses AR buffer tubes, the buffer tube aligns with the top of the shotgun receiver, so a pic rail or irons on top of the shell holder will end up being about the same sight height as an AR.

 

[Member 24198]

Nope, the plan is to have a pic rail and/or iron sights on top of the shells (those will come later, once we've ensured the mounting mechanism is solid). With a high mount grip that uses AR buffer tubes, the buffer tube aligns with the top of the shotgun receiver, so a pic rail or irons on top of the shell holder will end up being about the same sight height as an AR.

Won't that put the irons up too high since you point a shotgun as opposed to aim?

 

[bradsteen]

Won't that put the irons up too high since you point a shotgun as opposed to aim?

I don't think so, but guess I'll find out.