Remington 870 12 vs 20 ga Stock to Receiver Mounting !

[NnF000]

Hello,

I was thinking of converting a 20 ga 870 to a HD Weapon.
I want to buy a gun that CAN be converted to HD Tactical.
I want the High Tube Mounting System and to go the extra mile for the Stock/System and reviews, I decided on a Mesa Unit.
Problem is Mesa (and most other Manufacturers) only make one for the 12 ga and from what I have read the 12 ga is approximately 0.25” wider than the 20 ga receiver.
My question is, “Does the 12 ga and the 20 ga Stocks mount the same way, center bolt, bolt size, same mounting alignment slot", (terminology maybe off, newbie) ?

Thks for reading and thks for any information.

[Synchronizor]

This video explains stock interchangeability, fasteners, removal & installation, and other details. Watch through it, and let us know if you have additional questions.

For the record though, a traditional wood, laminate, or plastic semi-grip stock with a good recoil pad works very well for HD. They're simple, maneuverable, tough, and there's very little that can break or go wrong.

[NnF000]

Synchronizor,
Thks for the information I will watch asap.
I have it in my head to use the High Tube Stock Mounting like the M16, why, just looks.
Until I exhaust my resources I still want it !

[NnF000]

Synchronizor,
I watched the video, thks, it answered my question about the mounting in general.
from you and readings on this site I have the following info:
1) Mounting is the same… except for the size of each piece.
2) 12 ga Stock are approximately 0.045” wider per side, less than a 16th (.062) of an inch.

I need to get to a 12 ga & 20 ga 870 and do some measuring, I honestly believe an adpater can be generated for the High Tube Mounting.

I am going to contact Mesa and ask if they have any damaged High Tube Adapter and maybe I can come up with a spacer that will work for all Stock but mostly the High Tube.

thks again !

p.s. if you or anyone has the measurements I seek, pls let me know.
What I need:
1) 12 ga receiver measurements stock end.
2) 20 ga receiver measurements stock end.
3) OEM Stock measurements receiver end.
4) OEM Stock measurements receiver end.
thks

[Synchronizor]

Mesa Tactical already makes an adapter that allows large-frame stocks to be installed on small-frame receivers.

[NnF000]

Thks… been there, won’t work with High Tube Adapter !

I am in the groove now to build a 12/20 Stock Adapter.
Only problem… I now have the 20 ga but no 12 ga High Tube Adapter from Mesa to use for measurements and fitment.

May only need a a plate but may need more, only way to tell is to get one to try, which I do not have nor know of someone that has one to borrow so I asked Mesa to borrow a damaged one to work with for the duration. Long shot I know, who do I think I am but I know no one that has an adapter to borrow.

So i wait to hear back form Mesa Rep. and to find a machinist to machine what I am hoping to be an Adapter Plate to fit between the Mesa Adapter and the 20 ga REM 870Mag Receiver.


Synchronizor,
Great job n your Videos, the Stock one give good info as the others I have watched. Thks.

[NnF000]

Nothing has changed, no answer from Mesa, maybe they are working on something too and I stepped in where I shouldn’t; hoping so !

I will talk to a gunsmith in my area today and see what he has to say.

[NnF000]

Given up the ghost… not the Ghost Ring Sight though…
I matched up the 12 ga Stock and the 20 ga Receiver at a local shop, all eyeball dimensions but there is differences that I am not sure I can work around without my shop being finished and that wont happen for 6 months or so.

I looked for Stock in every corner of the Web, in every shop I found and Gun Booths at the local Hot Rod Runs and couldn’t locate what I wanted.
Took a local shops advice and tried out one of their guns with a Leo Adapter, stock was 1 inch lower than the High Tube Mount, felt OK, eye to sight location felt good, no straining to get the eyeball in the sight area; wife liked it too !
I decided to go with the Pheonix Kick Lite Tactical Stock. R15 look, has recoils spring to reduced kick and it is straight but with a lower mounting point. Since it cost less than the Mesa High Tube Mount and Stock, no additional cost for added adapter, it was a no brainer, one inch lower it is !

Gets me out of a lot of work too designing and making the 12 to 20 gauge adapter.
As I stated in another Thread, my next thing on the list is a 20 ga Heat Shield.