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"
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?
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?