Hammerli 208 trigger moving problem

Does anyone have a problem with the 208 or 215 trigger moving? My son tells me his moves but not much but after  a few matches it has to be moved back to location. I purchased a trigger and in the process of increasing it to 4-40 screw with Torx plus size LP10 wrench so a greater tightening force can be applied. I'm kind wondering if anyone else has this problem.

On a 208s or 215s? Yes, I have seen it happen and be the cause of alibis at a few matches.

Thanks! I'm not sure what screw size they are using but it could be either 2.5mm X .45 or #3-56. The two are so close they could interchange. However the head diameter size is that of a 2mm! But hex wrench size is 2mm or 5/64", the size for 2.5mm or #3 hex cap screw! Adam claims the hex wrench slips so I found 4-40 in Torx Plus. It has square corners to limit slippage so I'm getting set to increase the screw size to 4-40 Torx plus.
 I'll post here how it works out.

It could just be a sign that the threads are just worn too. These are older guns, would not be surprised at all to discover certain parts wear out, especially if they have seen extensive use.

Adams gun hasn't seen much use being he was using Army gun for years. I purchased a new trigger from Red Feather, didn't have the screw but hole was exactly the same. I could easily screw in the screw from Adam's trigger. Did buy the 4-40 torx cap screws and the LP-10 wrench, quite an improvement over the 2mm wrench (2mm=.0787",  5/64=.0781")
Have end mills ordered to fit the 4-40, I also will  move it back .010". Would like to move it more but then hole would not be round.

Larry Carter used to tell shooters not to over-torque that screw, but lots did because it moved frequently.  Mine never did (as of yet) have that issue.  Of course, as you know, both the rail and the trigger have to be "squeaky" clean.  If you're sure you won't need to adjust the first stage, I suppose some BLUE Loctite might be OK on the rails (away from the screw), and for sure, don't use red.

I assume that may be the case. Over-torque the screw mingt cause the Dove Tail to open at the top. Hard to say! Adam did say the AMU smiths did put in a bigger screw that stopped the moving.
 When I was shooting my Hammerli I don't recall having the problem but then again I was not using crisp trigger. I worked on the trigger to get a slight roll. Adam was using 3.5 pound trigger in the .22 and being the trigger it's self does not have a stop, that sudden stop after hammer is released may be what is causing the trigger to move.
 However I ordered all the cutting tools needed to put a 4-40 Torx cap screw in the trigger and will do it when components are delivered. When complete we will see if the increased torque helps or worsens the problem.

I completed Adams's Hammerli trigger. A photo of the 4-40 torx cap screw below shows what it looks like. Also the screw is the type that the Torx Plus wrench LP10 fits to limit slippage. I tried it on a test piece and the Torx Plus does provide addition grip, more than the Hex and standard Torx.
 I made a fixture to hold the trigger so anyone wanting their trigger modified let me know.