This rear sight configuration is the second-to-last model in the
evolution of the adjustable rear sights.
The earliest, on the 1899's and 1902's, has a single rear screw that is
threaded into the frame, and pushes up from the bottom side of the sight
leaf. (By the way, its "sight", not "site". ) A very small hole towards the
rear of the leaf gave access to the slot in this screw. In this variant,
the leaf is sprung downward.
The next variant, which was not as good, has the sight leaf sprung upwards.
The single rear screw is still threaded into the frame, but it has a large
conical head that sits directly on top of the leaf. Turning this screw
clockwise pulls the sight leaf downward, against its upward spring. This was
not a good as the earlier variant, as it worked loose easier. Both of these
variants provided no locking.
The next variant, also non-locking, was the forerunner of what we have today.
This variant utilized a slot milled into the topstrap. The single rear
adjusting screw has a large flat head, that sits in the slot. The sight
leaf itself is threaded, and travels up and down the screw thread as the
screw is turned.
The next variant, the second-to-last, is the addition of the locking, or
second, rear screw. This locking screw works against the vertical adjustment
screw. It is threaded into the sight leaf, and acts against the frame
top-strap, as it is tightened. This is what provides the locking action,
that was missing from all the earlier variants.
The last variant is what is on the K-22 second model; the micrometer-
click adjustment. This variant became the standard after WW2.
There is nothing collector-wise important about any of these earlier
variants. They were just part of an evolution, and there are enough guns
with each of this variants, to preclude any one of them from having
special collector value.
Later, Mike Priwer
