Re: Not enough down travel to zero scope
Wow, I looked on the manufacturers website and they do not seem to regard it as important to notify potential customers of the scopes internal travel. Its not listed anywhere, even on the scope manual that I had to find in a google search since there is no obvious place to find it on the web site.
So, in the absence of a specification, have you figured out what the internal travel is ? How many minutes per rotation of the elevation turret and how many total from top to bottom ? If the travel is around 40min (like many of the Nikon scopes) then clearly a 20 min rail is going to be a problem
You could consider putting a shim under the front of the rail (like 1 layer at a time of electrical tape) until you get back into territory where you have got surplus elevation left over. Just don't tighten the front rail screws tight, just enough to maintain contact. Once you work out your shim, then leave the shim in place and put bedding compound between the rail and receiver. You might want release compound between the rail and the receiver if you are likely to need to remove it often, else let it bond to the action.
You don't want to crank down on any of the screws but the back ones where you don't want any "lift" you would snug down tighter than the front. Put the scope on temporarily to verify that you are in the adjustment range. Then let the bedding set up. Clean up any excess compound right away so it looks neat. Give it 24hrs to set up fully, then remove the screws and apply blue loctite and tighten to the recommended spec (now that the bedding compound is cured and can support a load).
Most likely the LR scopes have more travel since they were apparently designed for longer distance shooting...