The Mid-Lock as it relates to the V-22 patent covers technology that eliminates lug ways that propagate forward of the abutments, which are in the middle of the receiver; the locking lugs on the bolt being in the middle of the bolt, hence, Mid-Lock.
If you recall the 40X, which is a mid-lock, the lug ways were broached through the length of the receiver, because those rimfires started life as a center fire blank. I noted issues with that approach, so I created the ability to have the lug ways stop at the locking abutments in the receiver....huge advantage to dictating a specific outcome and part of the V-22 accuracy equation. There are at least two pure clones of the 40X that copied the same lugway convention of the 40X. This is why I say, aside from the common footprint, the V-22 is quite a departure from all other features that are deeply inherent to the 40X.
Other popular rimfires have locking lugs in the rear of the receiver, a feature found in the Winchester 52, as well as the more popular German made stuff.
The only other mid-lock rimfire that had no lugways beyond the abutments was the Gilke, which were handmade and he only made two. I approached it completely different for the sake of Design for Manufacture.
Also, not specific to the mid-lock nomenclature, the lug profile used in the V-22 is not shaped like Remington lugs or clones of such. Look at the Skype logo, then look at your V-22 Bolt. I did this so the short lugways can be machined, not broached or EDM cut. Another significant departure from the 40X.
MB