Build a Better Mousetrap…

At last Saturday’s Casa Grande shoot, one of the guys showed up with his new invention, the SST-870:

His description:

Introducing the SST-870 AR15 buttstock adapter for the Remington 870 shotgun.


1) Allows the shooter to have proper cheek weld when using red dot optics on the shotgun. Optics can be mounted via the picatinny rail, which runs the length of the 870 receiver, or via other after market scope mounts.

2) Uses any AR15 style stock. The multitude of AR15 style stocks on the market will allow users to fit the shotgun to themselves and to their intended use for the shotgun.

3) Uses any AR15 style pistol grip. The user can switch grips as necessary to meet their personal preference.

4) Attachment point on left and right hand side of the SST-870 for Uncle Mike’s QD sling swivels.

5) Easier cross training for law enforcement and military personnel issued AR15s/M16 rifles, as well as competition shooters who use AR15 style rifles

6) Stock inline with the bore reduces felt recoil


1) SST-870 adapter piece is machined from T6 aluminum and mil-spec type III hard coat anodized for wear resistance and long service life

2) Optics mounting rail is machined to M1913 picatinny spec from T6 aluminum for mounting of red dot optics such as the OKO pictured or other sights. The rail is also mil-spec type III hard coat anodized.

I found that I couldn’t get proper cheek weld to use the red dot with the existing stock. The OKO sight was very fast to use on the shotgun but the stock hindered its ability to be used effectively…I knew if I could get an inline style AR stock on the 870 it would allow me to use the red dot sight effectively.

When Cavalry Arms started manufacturing AR15 buttstocks the idea became more feasible in my mind, but the thing holding me back was money to get the project going. Cavalry Arms was interested, but because they were bringing other products online R&D money for it was unavailable.

Last fall FN came out with the Police Shotgun and I had one of those “ah the bastards got it done before me” moments…but with a retail price tag of $700-$800 and availability as only a dedicated unit, I knew there was room for improvement. I also thought the A2 AR15 sights on a shotgun were somewhat of an over kill. I believed that an adapter to go on existing shotguns people already own was a better idea.

So I started actively pursuing the idea myself just before SHOT Show 2003. I recently acquired a loan and from the time I had the money in hand to first production article was 6 weeks. I haven’t spoken of the project publicly before because of the uncertainty of when it would be completed, and I did not want to give a heads up to any competition.

The first production run of 50 SST-870 adapters and rails is being machined right now. If everything goes according to plan they should be shipping in at most 3 weeks….I say “should be” because Murphy’s law likes to happen quite frequently in manufacturing. However, I don’t see any problems arising.

Design work on a model for the Mossberg 590/500 will be started at the end of the first production run of SST-870s.

Which is too cool, because I own a 590 myself. Can you say “Patent?”

Here’s the first production run out of the machine shop:

And here it is at the shoot, being test driven:

As you can see, it really relocates the bore centerline lower. Everyone who tried it really liked it. Unfortunately, I was too busy shooting clay pigeons with my Enfield. Maybe next time!

Leave a Reply

Your email address will not be published. Required fields are marked *