AK master mount won't stop moving

[DerMerchant]

I purchased an AK master mount a while back for my Clearview Investments AMD-63, as it did not ship with a riveted side mount. To secure the rail to the receiver (without movement), requires tightening the screws so much as to cause the receiver to flex inwards, impeding the movement of the bolt carrier along the receiver rails. The movement of the mount is very slight, and can only be felt by attaching my optic and pushing and pulling up and down, I can see the mount move and there are wear marks on both the mount and receiver confirming this, I have tried using washers on the screws (on the opposite side of the receiver) but they didn't do anything, I have also followed the instructions for installation on the AK master mount website, shaving down the shafts of the hex pins with a file. I was thinking of trying some of options listed below to tighten the mount

• Placing a piece of duck tape or gorilla tape under the mount
• Spray paint the receiver under the mount
• Apply JB weld under the mount

Any ideas would be appreciated, if you're not sure how the AK master mount works here is a link https://akmastermount.com/product/ak-master-mount-side-rail/
I have not fired the gun with the mount attached, so it may hold zero, but I doubt it, the movement is slight, but very noticeable.

 

[badkarmamib]

I am trying to figure out how something held on by the trigger and hammer pins won't have some flex. The pins themselves will have some play in the receiver. Maybe I am missing something, but I would expect even this system to be less-than-perfectly stable.

 

[Obturation]

It's imperfect for sure. Got a welder?

 

[DerMerchant]

I am trying to figure out how something held on by the trigger and hammer pins won't have some flex. The pins themselves will have some play in the receiver. Maybe I am missing something, but I would expect even this system to be less-than-perfectly stable.

I agree,having a gunsmith rivet on a traditional side mount would have been a better choice, probably.

It's imperfect for sure. Got a welder?

I actually do, an acetylene/oxygen welder I picked up used, and which I haven't had a chance to use yet. Wouldn't the heat from the welder compromise the heat treating on the receiver.

 

[Ohen Cepel]

How much does it effect accuracy? I know it's not ideal if it is moving but if you have a large red dot on it and plan to use at at close range it may not matter.

 

[Obturation]

I agree,having a gunsmith rivet on a traditional side mount would have been a better choice, probably.

I actually do, an acetylene/oxygen welder I picked up used, and which I haven't had a chance to use yet. Wouldn't the heat from the welder compromise the heat treating on the receiver.

I was thinking more along the lines of a tig welder. I think you're right, an oxy/acetylene weld would require too much heat into the receiver. But a tig weld would not compromise the reciever to any measurable degree, but then again, I'm not a gunsmith.

 

[DerMerchant]

How much does it effect accuracy? I know it's not ideal if it is moving but if you have a large red dot on it and plan to use at at close range it may not matter.

I haven't zeroed it yet because I'm not sure, I've had bad experiences zeroing rifles with screwed up optics and mounting solutions before, and didn't want to waste ammo on it. I have a 4 MOA red dot attached to the rail I plan to use, so it may not make much difference. It would probably be best if I tried to zero it before doing anything drastic.

 

[skeeterfogger]

Seems finding a way to drill and tap 2 holes for screws installed from inside, on sheet metal reciever, to hold it from the slop. From outside on milled reciever. Or maybe drill and tap the end of the pins and add a firm rubber washer with a washer on top to put some pull on the pins along with bed the pins with JB.
Gun smith rivet good idea.

 

[herrwalther]

I actually do, an acetylene/oxygen welder I picked up used, and which I haven't had a chance to use yet. Wouldn't the heat from the welder compromise the heat treating on the receiver.

Yes it will. Too much heat from an Oxy torch could also damage the trigger springs on the other side of the receiver. Small parts take less to heat up than larger parts. Propane torches burn about half as hot as Oxy-acetylene. Depending on the type of steel for both the side rail and receiver, 3600 degrees may be enough to weld the two. If you cannot get your hands on a TIG or MIG welder.

 

[illinoisburt]

Epoxies like JB will not work well thinned put between the pieces. If you have anything thick, it will either be in the way or will have too much slop and crack within a short time. Assuming you are okay with a semi permanent mount, I would sweat the rail to the receiver. Since there is a bit of surface area and mechanical fastners, simple low temp plumbing solder will hold fine. Clean the metal surfaces with a little steel wool and rubbing alcohol. Brush with small amount of flux. Assemble as before with screws on side away from.the mount. Only needs to be snugged down, not gorilla tight. Place a damp rag inside the receiver over the trigger components to act as a heat sink. Set at about 45° angle. Apply heat along the botton edge where mount and receiver meet, sweeping slowly back and across the length of the mount with a standard propane torch just until the solder melts and flows into/ between the two from above. The heat will wick in the solder between the two pieces and leave a clean faint line along the top seam. Torch off. Remove the damp rag (will be hot), rewet, and dab at the mount and receiver to cool it off. Dry with compressed air, relube and its done.

 

[Varminterror]

Personally, I’d look first at creating an alignment pin/mortise set up. Any welding would be done only to the mount, not in proximity to the receiver. Drill a hole in the mount, install, mark the hole position on the receiver, drill. Weld a pin into the hole, drill another hole in the mount at the opposite end, install, mark, drill, weld the second pin into the mount, bingo bango, double alignment pins to secure constant and repeatable relative engagement and position.

 

[Bwana John]

I would take it as a sign that the AK was not intended to mount optics on.

Something about silk purses and sow's ears.

Or lipstick on pigs.

Kinda like mounting a laser on a shovel.

 

[drk1]

Thanks for the question and sorry to hear about your situation. One of the main selling points of the mount you have chosen is that there are "No Permanent Modifications". However, with all of the options you have listed and other have suggested there would certainly seem to be some permanent modifications. If you're going to that extent to attach your scope, it would appear that the "no permanant modifications" is no longer an issue for you. In other words, if you're going to the extent of modifiying your rifle permanent, why not get a better quality mount and put it on your receiver permanently and securely? There are lots of other options out there before you get to the point of considering glue and duck tape! Either send the mount you have back to AK or simply mark it up to a lesson learned. It's one of those "if it sounds too good to be true" experiences. Best of luck and let us know what you decide to do. Some pictures of the outcome would be great. Thanks again.

 

[amd6547]

They used to sell a russian made rail that attached with two screws from the inside of the reciever.
I used one to put a PSO on a AK I had.
Two part epoxy on the base, and the screws, and it worked great...plus, it looked OEM.
And, to the poster who said scoping an AK is worthless, I disagree. They are largely made to use scopes, with that handy rail most have. My 5.45 Saiga, with a 2moa TRS25 is an accurate shooter at 100yds, using surplus 7n6.

 

[mshootnit]

they used to make a good one called the mpk-02 side rail kit. I mounted seceral of these on SLR Bulgarian milled rifles.
No flex or problems.

 

[illinoisburt]

Curious how this turned out. Did you find a workable solution?