Ok as Gunrunner pointed out his scope mount is not fitting on the rail correctly (loose)? So I went grabbed one my Eotech EXPS's off of one my AR's and tried to install it on this PKM rail. The EXPS has an adjustable quick release lever on it so if its sits kinda loose on the rail but you can adjust it to so the mount will get tight on the rail.
One thing that I noticed is when its tight on the rail it's sitting kinda canted on the rail ever so slightly, you can barely see it when looking at it head on. This rail is a few thousandths thinner then a U.S spec rail. I tried different rings on it and naturally all the overseas rings fit perfectly on it with no problems at all. You start to run into problems when you put US made higher end rings or even the QD rings such as the Eotech mounts. This is not good so I did some digging around on the net and found a solution for this budget PKM rail.
So after searching around I found a machinist who is making new U.S Spec M1913 picatinny rails on his CNC machine. He is able to make it any length and can do custom rails any way you want even weld them onto your guns (these are steel rails). So after talking with him and telling him what I need he said no problem he can make a rail for this PKM mount. So we call this a "PKM rail retrofit".
The plan is to machine the old rail completely off and install the new US spec steel rail onto the new mount. So I had him machine up a custom rail for this and he installed it back onto the mount via machine screws (this thing is rock solid). So now this mount is up to spec on the rail and it will accept any type of QD mount and all standard US rings without any problems.
If you plan is to run the Chinese rings only then you really don't need this upgrade for your rail as the rings will fit fine.
So anyways this is a neat little upgrade you can do to your PKM mount so you can run any rings as you wish.
Here are some pics of the new retrofit M1913 US spec rail.
Nice machine work with the new rail.
So far for this experiment.
1. Cost of the PKM scope mount $33
2. Cost of PKM rail retrofit with new US spec rail $90
Total cost for the budget PKM rail $123 (Not too shabby)
** I talked to the guy who machines the rails and asked him if he can do more and he said no problem at all so I will give you guys his info in case you want to do yours. Its an awesome upgrade for this mount and worth the price he charges. The price is $90 and that includes return shipping. (You ship your mount to him OR you can buy one online and have it shipped directly to him to save a little on shipping - Just let him know so he knows.
His contact e-mail is: email@example.com
His name is "Matt"
Subject in e-mail "PKM rail retrofit upgrade"
*Turn around time was same day as receiving.
Just tell him Rich sent ya so he will know.