Mrussel, right you are, but he is 'gluing' the rail on without screws. I know its been done, but for me, on anything with a kick to it, I gotta have some 8X40s too! I hate scopes falling/flying about and bouncing off the ground.
Most of the epoxies on the market are just not going to be appropriate for holding a scope on. There ARE adhesives that are used for these sorts of things,but the parts usually need to be the correct geometry as well. I used to work in a plant that made adhesive tape and the first thing they gave me when I started was a textbook on adhesives and told me to read it cover to cover. One of the chapters was on applications and they described how Lotus used adhesives on its aluminum framed cars in many cases replacing most of the bolts and welds in the frame. It was claimed that it not only reduced weight but increased strength because it eliminated the stresses in the metal that holes for bolts or spot welds cause. They used special adhesives with the correct properties to hold aluminum together,and with enough flexibility not to shear under stress,and with the correct expansion coefficients not to expand at a different rate and come loose. They also designed the frame with areas with sufficient surface area to create a strong enough bond. If I tried to take an Chevy Impala,remove all the bolts,drill out the welds and hold the whole thing together with JB Weld,it would be a disaster.
In short,I think you COULD get it to work,but you would need the correct adhesive,that could take quite a bit of heat (my Mosin Nagant last week go so hot shooting 50 rounds rapidly through it that it started SMOKING and the residual cosmolene started bubbling out from underneath the wood over the top of the barrel and sweating out of the stock. The range master actually came over to make sure everything was ok. (The conclusion was,it was fine,becuase back during the "Great Patriotic War" it probably got a lot hotter than that,and in fact,it shows why they added the top piece of wood to the it,as the metal was literally to hot to touch)
My first instinct would be to cut the scope mount to the correct radius and then turn the receiver to get a very good fit. You would want a lip left on the receiver before the opening/ejection port (or whatever you call it) for the scope mount to rest against. In fact you would probably want to make a lip i front too,so it sort of rests snugly in a channel. Then the adhesive would not have to take appreciable shear forces,so long as it had enough flexibility (which it has to maintain with gun oil and heat) so that it could slide slightly forward and rest against the front lip or backwards and rest against the rear. (by slightly were talking thousandths of an inch or less.) If the adhesive is brittle it would just shear off. The problem is of course,you cant just go turning off lots of metal on a receiver so it would not be appropriate for retrofitting to an old rifle,but instead to a newly manufactured one.
Somehow though,I dont picture the people who claimed to have successfully glued their scopes on as manufacturing custom receivers made with state of the art adhesives and exacting tolerances,to leverage the power of modern machine tools to create exacting tolerances cheaply and economically,while reducing costs and increasing strength of the gun by eliminating drilled holes and stress points. Instead,I imagine a guy in a "wife-beater" and a baseball cap advertising ether some sort of farm equipment,or a sporting event involving some sort of vehicle with a gigantic engine,either accelerating very fast or pulling something very heavy,smoking a cigarette while slathering on the JB weld with a pop-sickle stick and sticking the scope down while holding it crookedly in place with rubber bands or electrical tape until it cures.
Their claims that "It holds just fine" only mean that the epoxy as not fractured enough and degraded from the heat enough to cause the scope to go flying off and shattering on the concrete at the range. I know there are people that have claimed to do it,but its a huge claim and I have never seen epoxy hold like that and I think,even if its actually done well,and not the huge mess that I envision with the popsicle stick and rubber bands, I really cant imagine it not eventually failing on something that kicks like my NEF 12ga,and if you have a smaller one,then there is easily enough "meat" in the barrel to drill it and tap it for a scope mount. (I understand there is in the 12 too,but you just have to be REALLY good to do it)
In my other post,I misunderstood what was said. I thought he was using the thread locker and trying to hold the screws in place and it kept vibrating loose. The Loctite product I saw was a thread locker being marketed for scope screws. (I noticed it becuase Ive been using the green thread locker on scope screws,and while it works well,I wondered if there would be any advantage to the stuff made specifically for my application)
Ive considered soft soldering a mount to mine. There are solders with quite good strengths that melt at very low points. Ive been meaning to run the numbers and see how much sheer force the scope mount will take and see if the solder will hold if done properly. What I was thinking is to get a steel rail with the right diameter and then scrape it in to fit the barrel perfectly. Then I would solder it on. The secret of getting solder jobs to hold is have a optimal fit. It wont hold if there is too much of a gap. Its just like glue,there should be a thin film between the pieces,but if you expect a thick blob of glue,or solder,to hold,your going to be dissapointed as the bulk mechanical properties of both are just not going to be up to the job.