Bruzer, I take it you want to build a LR Rig on a Ruger M77 in .26 Nosler. You seem set on a Rock Creek 5R bbl, "short and fat", and want a scope that matches your planned finish on your unspecified stock. Only certain stocks will take flush cups. You are also running low on funds.
If this is your first custom rifle build. I would suggest backing up and regrouping. Having built several Custom LR Rigs on R700, M70, and Lawton 7000 actions, I can tell you first hand they cost a minor fortune, (by my standards), but are well worth it. I'm finishing my last one, exactly what I want, after almost three years. I have hunted it, but always make changes.
Build the rifle first, it will cost more than you think. BBL blanks still need chambering, fluting,(some like it, some not),fitting to action,and possible contouring and threaded/muzzle brake. Good quality trigger is a must. True action,(good smith will tell you if yours is worth it), Stock, and, bedding if necessary.
Personally, unless you have started this project, I would recommend starting with a R700, M70, or a Savage as a donor action. The R700 and Savage have a huge selection of aftermarket and factory parts, as a bonus, you can even re-barrel a Savage yourself. Both will take a number of scope mounting options, I prefer Picatinney Rail myself w/ Seekins rings. Great triggers are available for both also, along with extended box mags, DBM, and stocks.
I would hunt what I had, and take your time building your dream rifle. It's worth it in the long run !!!
