Never a slam, but maybe you should try using them???
I had to return a Luppy because of fogging, and a friend up the street purchased a Remmy 700 Mountain Rifle in '06 SS branny new and also picked up a Luppy VX3 with rings and base, tried to sight it in, and it wouldn't. He thought there was something wrong with his rifle. I told him to bring it over, I stuck my 6.5-20 Luppy VX-III on it, and it shot amazing groups.
He took the scope back, exchanged it-end of problem.
Like I said before, if its made by man, things can go wrong. Luppy isn't fool proof, but they DO have amazing customer service, and make a great scope. I own several, mostly high-end M-1's and M-3's.