S&W WEIG-A-TINNY Mount SWHPMNTS installed on 657

[Elric]

http://jackweigand.com/swhpmnt.html

Finally quit ditzing about, unshipped the original S&W N frame rear sight, and installed the no drill three screw Picatinny scope base. It slides in the top slot and has a recoil lug that directly mates with the slot for the Rear Sight Elevation Stud. All three screws (included) started normally and bottomed out with the tip of each screw BARELY inside the top strap. In a word, perfect.

Unship the grips and place grip portion of the frame in wood jawed vice (or other non-marring vice jaws).
Open cylinder, this lets you visually check screw depth of the three mount screws.
Unscrew Rear Sight Elevation Nut. (it is retained, it will stay in place)

NOTE: Unscrew Rear Sight Elevation Nut first, that takes all the pressure off the Rear Sight Leaf screw. The Rear Sight Elevation Nut has a spring loaded Rear Sight Plunger that prevents it from falling out.

Unscrew Rear Sight Leaf screw
Lift Rear Sight Leaf up and remove.
Slide Rear Sight Elevation Nut rearward and remove.

NOTE: The Rear Sight Elevation Stud is pretty small, and after you unscrew the Rear Sight Elevation Nut, you will find this SMALL little square sitting on top of the slot right under the Sight Leaf. Now >IF< you followed my suggestion to put the revolver in a vise, this small Stud will be sitting quite neatly on the slot. If you are holding the revolver in your hands, this small square may slip out and fall on the floor...

NOTE: Suggest you use a small zip-lock to hold complete rear sight leaf screw and parts.

Slide Weigland sight into slot. All three holes should line up spot-on. If they don't, stop and check how you slid the sight in. If it still doesn't make sense, call Weigland!

Install all three screws partway, then tighten them down at the same time (think of tire rims!)

NOTE: You may choose low strength loctite, but IMHO, the design has that built in recoil lug. I didn't use Loctite, might be bemoaning that fact, but the 6-48 (not 8x32 as first thought) socket screws are steel.

Replace grips.

NOTE: Weigland says "Screws are supplied and are 6-48 thread."

NOTE: Earlier S&W revolvers may need drilling. Please consult the following videos:

Installation video:

How to ID S&W Factory D&T Revovlvers:

How to D&T Your Revolver:

 

[gman]

What are mounting for a sight?

 

[Elric]

I have a 2x pistol scope, 2x28 IIRC. I watch a deer crossing about 75yds out.

 

[Pistolero]

I installed one of those just about a two weeks ago. I am certain that mine
were 6-48 screws, but I tapped them. Are you sure yours are 8-32?

My research showed that 6-48 was what S&W uses, and the screws that came
with the mount fit my 6-48 holes. I put a minired dot Bushnell on a Model 14.

Bill

 

[Brad]

8-32 is a pretty hefty screw for bases or rings.

 

[Pistolero]

Correction, mine is the mini mount, which is the same, just shorter. But the holes
have to be the same since they are factory drilled and tapped in newer
S&Ws.

Bill

 

[gman]

Thinking of putting the mini mount on a super blackhawk to install a reflex sight.

 

[Pistolero]

The mini picatinny mount worked fine, but I had the added issue of the gun
being old enough to not have been drilled at the factory. A friend with an NC mill
drilled mine, makes it easy to get all three holes perfectly spaced and in a straight
line, parallel to the frame sides. If it is factory drilled and tapped, it is really
easy, they did a very good thing when they added that to the production of the
pistols.

Bill

 

[Pistolero]

Is the SBH drilled for a scope mount at the factory now?

 

[Brad]

I don't think so. Ruger makes the "Hunter" version with a run in the barrel set up for ruger scope rings. Kinda takes away a need for drill/tap

 

[gman]

The mini they make for the blackhawk uses the existing rear sight screw hole. No drill no tap.