Re: leatherwood art scopes
In a word: don't.
The Leatherwood ART scopes are neat and add a touch of nostalga to an M14 or M1A rifle. I have one on my M1A and it's definitely a cool old piece of kit, but it never comes out of the safe.
For real precision shooting, an ART is just too complex and cams are prone to wear; the bases and adjustors have too many moving parts and too much complexity. They are likely to "Walk" rounds around the paper. An ART will likely drive you nuts on the range!
That said, there are people (probably some here on the forum) who can really make them work well. And it is definitely possible to use them very successfully with a lot of skill and practice and careful attention to detail at setup. There is nothing *wrong* with the design or the theory of an ART. But you have to be something of a master to make one work to its potential. And if you want to go through the learning curve, you will probably get good results.
For your budget, there are many scopes out there that will give you excellent results and much better repeatability, better glass, reticles, etc.
Cheers,
Sirhr