On the Buckmark there are two threaded fasteners that hold the top strap on, they use an allen wrench to tighten them down, remove, etc. On the older Buckmark it used a screwdriver, I suspect Browning changed that to prevent torque problems. The older Buckmarks had a solid slide assembly to hold the firing pin, the newer ones use plastic. The fastener nearest to the grip on my pistol kept coming loose, lock washer, lock tight blue formula, nothing kept it in place.
The Buckmark uses potmetal for the top strap, I have read of the camper model getting cracks in this area, on my Buckmark you could see the paint coming off from the impacts of the spent shell casing, fortunately this was all inside the gun. Steel would be a better metal for this application.
This area takes an impact from the recoil of the slide, hence the loosening. Browning did put in a recoil buffer, otherwise the impact would crack the frame. This is also where the rear sight is, so that will affect the setting for the point of aim as well.
Ruger is rock solid. The only trouble free semi-autos in .22 available are the Ruger Mk. series, the earlier Colt Woodsman and the older High standards. If you like a gun that shakes apart, get a Smith model 22A, the Beretta Neos, and the Buckmark. Nice thing about the "shake aparts" is they are at least cheap!
I have been a shooter since the 1960's and tinker toy junky guns don't do it for me.