S&W 76 sturdy locking folding stock. Anybody interested?

[Chief762]

Opee,
Put me down for one.
Chief762

 

[rfsolutions]

I have an MK760 which should work and a buddy with a few M76. Put me down for at least 2. rfsolutions@cox.net

 

[opee]

I am getting a little difference in measurements between the S&W and the MK 760 subguns regarding the slot distance on the grip block. This is where the wire stock adapter slides in as well as the new adapter. If anyone can provide the dimensions using a digital caliper of this slot, that would be very helpful. There is a slight step down on my S&W model (circled in blue) that does not appear to be on the MK model.
Looking for some verification please. (Blue arrow)
S&W distance---appx .1270"
MK 760 distance-----appx .1440"

Thanks

 

[opee]

S&W 76, MK 760, Grip block and adapter dimensions.

I received a reply today from another forum member and he is telling me his Irvine built MK 760 does have the same dimensions as the OEM Smith 76. There is a slight step down in the slot similar to the schematic picture. I have also received another picture of the grip block that has no step down at all. That particular grip block has “Model 760 SMG” stamped on it. What I dont know: Was the grip block changed after the Irvine made Subgun?

Thanks

 

[Kimber1911]

Can you post a photo of the area the diagram is referencing.

 

[opee]

S&W and MK Grip Block Variations

Picture posting challenges!

 

[opee]

Pics of Grip Block MK760 and S&W 76

Here are 2 different pics of the grip blocks.
The top one is a MK 760 Subgun and the bottom pic is from an original OEM S&W 76 Subgun.
The MK 760 with no step-down I believe is a Fruithurst, AL MK 760.
The spacing in the gap of the Fruithurst MK 760 is about .1440".
I have a report from another forum member that his MK 760 from Irvine, CA also has the step-down just like the S&W 76 does. And the gap measurements are the very close to the same. (Appx .123")
You can see there is a step-down in the gap space of the S&W. The gap on the S&W is about .1235"
If I have 100 adapters machined, I would likely keep the same specs to fit the OEM S&W guns, and probably other MK variations.
For those that do not have the step-down on your gun, you may be required to add a small brass shim about .5mm in thickness to obtain a very tight fit.

If those of you who have MK 760 guns, could you take a look and see if you have a step-down or not?
So far, the Irvine CA guns do have a step-down, and the Fruithurst AL guns do not have a step-down.
It would be interesting to see if this rule holds true for all the subguns made in AL, or CA. Or perhaps other later manufacturing locations?

 

[DeadEyeDonna]

Hello Opee.

Color me very very interested for a Jim Burgess SW76.

 

[opee]

Hey fellow S&W 76, MK760 owners. Have received a lot of positive feedback on owners interested in this stock adapter.
I have found there are slight variations between the different guns on some of the measurements. (Between OEM S&W 76, MK760 Irvine, CA, and MK760 Fruithurst AL.) The variances have been between .001 to .003 thousandths. This variation can mean the difference between adding a shim, or not to insure a good snug fit. What I have decided to do is add two small bosses of metal in the machining process that are going to be appx .025 thousandths tall. This will require each owner to use a small fine tooth file to custom fit each adapter to his or her gun. It’s really very minimal filing required, and then you can choose to use a shim or not. (Please keep in mind there will be no modification or filing on the gun itself.)
I’m asking this question to see if owners would be willing to do this small amount of fitting. Please let me know.
If so, then I will begin working with my CNC shop to begin production.
Appreciate your honest feedback. Thanks

 

[nklf]

I don’t have a problem with minimal fitting of the stock. However, I will need some instruction so I do it correctly. If the adapter has to be fitted to the gun, why would you need shims?

 

[opee]

NKLF:
Filing of the bosses technically will not require any shims. The shims I have tested so far with success are a very thin .5mm thickness sheet of brass, or a couple different types of tape currently on the market.
But if someone were to file the bosses all the way down to flat metal, then a shim might be required? Basically, there are a few ways to skin this cat and still have a nice fit to your 76/760 subgun.

 

[Fulliautomatix]

(3/11/21) Here is an update on my S&W 76 Stock Adapter project.
I have a CNC machinist ready to go with a 5 and 7-Axis machines, but need more 76/760 owners to show interest in having a very secure folding stock to shoot their 76 with. Would like to have some 76 and 760 owners measure a couple of dimensions to see if there could be any differences between guns. I don't think so, but really need to check this before manufacture.
The adapter is made from 4140 gun steel, so it will not bend, flex, under stress. The 2 adapter parts will be finished, and may require a small amount of fitting for the tightest fit.
If you are interested in buying an adapter, or providing a couple of measurements for me that would be greatly appreciated.
Email me at: brmiles@sbcglobal.net
Let me know if there are other forums that I should post to get the word out. Price for the adapter will be $200, and you supply a 1913 style folding stock, such as Sig and others. The pic I have posted is a Sig Sauer Minimalist Plus stock.
Thanks, Opee

I sent you an email, haven't heard back yet, but I have a Burgess gun and am interested in one of your adapters. Let me know if you need any measurements verified.

 

[Haris1]

I still want one and will adapt as needed
Haris00045@gmail.com

 

[jknorton]

I'm In

I do not mind the filing - will take one for SW76

 

[opee]

To all S&W 76, MK760, and similar design owners who have shown interest in the stock adapter on this thread, I pulled the trigger on a manufacturing run with a 5-Axis CNC machine today to produce one batch of the adapters. We made several changes and fit tests before finalizing the dimensions. If you are interested, please let me know as soon as possible. Likely only making one manufacturing run due to the overall costs and time of this project. Ill try to PM those of you who have replied, but please send me an email with your contact info. If you know other fellow owners that may be interested, please share.
Contact me via email for further details.
Brmiles@sbcglobal.net
Thank You, Opee

 

[deuce]

Try making one on a milling machine. The one you have, took at least 8 hrs to make & fit.
Would like to see your finished adapter.

 

[opee]

Deuce:
I believe the first adapter you made (~3 years ago) is still on my S&W 76 today. It was from that adapter that I asked 2 professional engineers to spec everything down to .001” of an inch, and add any improvements to allow fitting on multiple types of the 76 design…. S&W 76, MK760, etc.
Fast forward to today, and with the help of a 5-Axis CNC machine it takes about 15 minutes to mill a beautiful adapter from a solid block of 4140 steel. Adapter is then finished in a black Manganese Phosphate finish. Although a hugely expensive project, it has produced a very nice modification for the 76 stock design without having to make any changes to the actual registered Subgun. I’ll send you a few pics when I get a chance.
Now, every 76/760 owner out there can fire their gun without any movement of the buttstock….. A huge improvement!

 

[Haris1]

opee,the stock adapter you sent me arrived yesterday and i was super impressed with the workmanship.
I will take pics of the adapter and then after I install it. Its a supurb improvement to the 76
without any mods to the gun. Thanks for your contribution!!
Below are closeups of the adapter and how the gun looks.Fantastic
SIG SAUER STOCK EXTENDED-30 INCHES
SIG STOCK COLLAPSED 28 INCHES