Mossberg 990 semi-auto Aftershock

SIGforum

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September 26, 2025, 06:37 PM

parabellum

Mossberg 990 semi-auto Aftershock

September 30, 2025, 03:04 PM

911Boss

Well mixed info on this one. Some sources say that 500/590 adapters WILL work, others say they won’t. Only place I’ve found with a 990 specific adapter was $100 for it.

Decided to take a chance on Midway’s $32 500 adapter. It arrived today, and while not a “proper” fit, was able to Dremel it enough to work.

With it along with some spare parts (grip, tube, brace) I stocked up on awhile back I cobbled it together.

Will see how it feels shooting, everything is tight but the geometry for the grip is a bit off.

This message has been edited. Last edited by: 911Boss,

October 01, 2025, 10:33 PM

dry-fly

I’m on the hunt to SBS one of these. They don’t stay in stock long.. my RSR called and had one a week ago but I didn’t have the $$.

October 02, 2025, 08:50 PM

rkentm

The $100 adapter has much better geometry. Will post a pic ASAP.

quote:
Originally posted by 911Boss:
Well mixed info on this one. Some sources say that 500/590 adapters WILL work, others say they won’t. Only place I’ve found with a 990 specific adapter was $100 for it.

Decided to take a chance on Midway’s $32 500 adapter. It arrived today, and while not a “proper” fit, was able to Dremel it enough to work.

With it along with some spare parts (grip, tube, brace) I stocked up on awhile back I cobbled it together.

Will see how it feels shooting, everything is tight but the geometry for the grip is a bit off.

October 03, 2025, 04:49 PM

rkentm

This is the Outlast Supply adapter and the resulting grip angle.

October 06, 2025, 07:05 PM

jed7s9b

I picked up one of these this weekend. It’s neat, feels solid, made in USA, smooth action, light trigger, cycles low brass bird shot, and has pretty good pointability. The recoil is a bit punishing on the grip hand with a little sting and setback. Loud. I like it more so than the pump action. It’s a hoss.