Snakeoil
Well-Known Member
PROBLEM STATEMENT: The Model 82 Kimber .22LR Government Model rifle was made as a result of Kimber winning a bid (low price bidder) to make a 3-position rifle for the US Army. As a 3 position rifle the sights were never intended to reach out to 300 yds. Since the front sight was sourced from Diana, the mounting block is unique to the sight. The mounting hole spacing is unique and the width of the dovetail is unique. The height of the mounting block is about a short as possible, preventing the use of a shorter custom made block for the rifle be able to shoot out to 300 yds. The only alternative is to raise the rear sight. However, the mount for the rear sight is a grooved receiver top similar to many commercial .22 rifles. The rear sight mounts directly on and clamps to the male dovetail created by grooving the receiver. So you can’t just throw on a taller mounting block.
SOLUTION: Make an adapter block that mounts to the grooved receiver and provides a similar male dovetail at a higher location to raise the rear sight, aka a lift block.
Okay, that’s enough serious BS for now. Steve is my shooting partner. He bought the Kimber about a month ago. It could not get out to 300 yds. So, cutting to the chase, after looking at Steve’s rifle today at the club, I had a moment of lucidity (rare these days) and came up with a very simple solution. I brought the rifle home with me and went to work. The solution was to machine a simple lifting block with a female dovetail to engage the receiver and a male dovetail onto which the sight would mount. Below is the blow by blow for the lifting block adapter.
Here is the receiver with the rear sight removed. You can see the grooved section. The sight mounts to the grooved portion behind the loading port.
The machining process is pretty boring. So, here is the raw block after cutting both the dovetails. The fit to the receiver needed a few taps with my plastic hammer. But after putting it on and off a few times it is now a nice slip fit with zero play once in place. You will see two holes in the top dovetail. Those holes are threaded for 10-24 socket head set screws. I had considered a clamping arrangement for the block, similar to how the sight mounts to the rifle dovetail. But since there are two dovetails, one above the other, and the top one cannot flex, I abandoned that idea and went with set screws to secure the block to the receiver. And before you get your shorts in a bunch over the screws gouging up the top of the receiver, I made little nylon pads that go between the screw and the receiver.
Here is the sight mounted on the lift block. Fits like a glove. And not OJ’s glove.
With the block made, now it was time to make it pretty. Step one was a trip thru the bead blast cabinet.
Next was a coat of flat black paint so it would look like it belonged on the rifle. The sight is also a matte black finish. Set screws are installed in this photo.
Here is the underside of the female dovetail that mates up with the grooved receiver. Note the nylon pads to protect the receiver.
With the block painted, it was now simply a matter of mounting the block to the receiver and then the sight to the block. The following pics show those final steps.
I did not measure the actual increase in height. I maximized the piece of aluminum I used to provide as much lift as possible. It’s about 3/16”. If Steve finds that he cannot get the sight low enough to shoot 50 yd, we can always put the block back in the mill and cut down the upper dovetail to reduce the lift. Hopefully, we will not have to do that.
SOLUTION: Make an adapter block that mounts to the grooved receiver and provides a similar male dovetail at a higher location to raise the rear sight, aka a lift block.
Okay, that’s enough serious BS for now. Steve is my shooting partner. He bought the Kimber about a month ago. It could not get out to 300 yds. So, cutting to the chase, after looking at Steve’s rifle today at the club, I had a moment of lucidity (rare these days) and came up with a very simple solution. I brought the rifle home with me and went to work. The solution was to machine a simple lifting block with a female dovetail to engage the receiver and a male dovetail onto which the sight would mount. Below is the blow by blow for the lifting block adapter.
Here is the receiver with the rear sight removed. You can see the grooved section. The sight mounts to the grooved portion behind the loading port.
The machining process is pretty boring. So, here is the raw block after cutting both the dovetails. The fit to the receiver needed a few taps with my plastic hammer. But after putting it on and off a few times it is now a nice slip fit with zero play once in place. You will see two holes in the top dovetail. Those holes are threaded for 10-24 socket head set screws. I had considered a clamping arrangement for the block, similar to how the sight mounts to the rifle dovetail. But since there are two dovetails, one above the other, and the top one cannot flex, I abandoned that idea and went with set screws to secure the block to the receiver. And before you get your shorts in a bunch over the screws gouging up the top of the receiver, I made little nylon pads that go between the screw and the receiver.
Here is the sight mounted on the lift block. Fits like a glove. And not OJ’s glove.
With the block made, now it was time to make it pretty. Step one was a trip thru the bead blast cabinet.
Next was a coat of flat black paint so it would look like it belonged on the rifle. The sight is also a matte black finish. Set screws are installed in this photo.
Here is the underside of the female dovetail that mates up with the grooved receiver. Note the nylon pads to protect the receiver.
With the block painted, it was now simply a matter of mounting the block to the receiver and then the sight to the block. The following pics show those final steps.
I did not measure the actual increase in height. I maximized the piece of aluminum I used to provide as much lift as possible. It’s about 3/16”. If Steve finds that he cannot get the sight low enough to shoot 50 yd, we can always put the block back in the mill and cut down the upper dovetail to reduce the lift. Hopefully, we will not have to do that.
