Very clever design
Its really hard to review just one part as these are designed to be a two piece system, so Ill include both here and post them at both the lower rail and upper rail reviews. I put these on a new Arsenal SAM7SF. Both rails are surprisingly light. Putting it on at first was a little tight as the Arsenal has a sling swivel right in the way so you have to turn it just right to get the lower rail to slide on. It was loose after it finally slid on, so following directions; I removed it and tried to adjust it. The spring loaded floating anchor was really stiff. The adjustment nut fits into a hex recess on the floating anchor. I found the best way to depress the anchor to allow adjustment was to use a 5/16 nut driver to get it moving. Once it moves, hold it down with a finger and use the nut driver to adjust as necessary. Turn clockwise to tighten the attachment and reverse to loosen. Make sure the adjustment nut goes back into the hex recess under spring pressure when you are finished. Got that adjusted and the lower rail locked up tight. Next the upper rail is attached in a convenient position on the lower rail. The upper rail can move laterally in its slots which allow the mount to be positioned exactly over the bore. Call it a gross windage adjustment. I measured the clearance between the bottom of the upper rail and the rifles rear cover to be .118. Four 8-32 socket head screws are furnished to secure it. I suggest using just two until everything is where you want it. The rifle can be shot with just two screws to make sure it is centered. Once you are happy with the position, you can install the other two screws and Loctite them if you want. The upper rail also comes with two roll pins which are used to stake the mount for extreme duty. To do that you have to drill two .125 holes in the lower rail aligned with the staking holes. Of course that is not really staking like on a 1911 grip bushing, but I digress. Once you drill those holes, you are stuck with the position of the upper rails as it would be pretty tough to get the roll pins out as they would be going into a blind hole unless you drill those .125 holes all the way through. My opinion is if the unit is ever subjected to such a load that the screws wont hold, it will likely be destroyed whether or not there are roll pins in place. Overall the quality and finish is great. I had no problem getting the upper rail to be centered over the barrel. The Picatinny style rings I used fit just fine with a tight lock up. The AK is not a tack drive but I expect that it will make my late 60s eyes shoot a bunch better with a low power scope rather that those tiny irons.
