For a long range precision semi auto, go with an AR-10/LR308 rifle. I love the M1A platform as much as anyone but it takes a lot more work to build one to shoot accurately - and maintain that accuracy - than it does the AR platform. ...
M1A, HK91 (PTR91), FAL
Pass on the AR10
Its and easy choice for me. An armilite AR 10. You can get one a budsgunshop.com for $ 2,500.