jeepkid, I have a FN SPR A1 with A3 McMillan. The rifle shoots great with 168 SMK's and recently tried some 180 SMK's I had on hand and it shootsthem consistantly into 3/8" or less with IMR-4895.It's a .308 and it's twisted 1:12. BC is right on about being somewhat heavy and a snap to clean with it's chromed bore.
The A3G is their best tactical rifle and it's guaranteed to shoot 1/2 moa , I couldnt find one when I was in the market so I settled on the A1. I now have a hankering for a higher end .308 and have a Sako TRG 22 on order at the moment but that are very hard to find.
I have readof several others in forums that have had trouble with the accuracy of various FN model and also lack of customer service but in my personal experinces havent nary a problem and would reccomend one if you wanted a decent OTC tactical rifle.
Kimber is now making a tacical model based on their 84 action which is a copy of a CRF Winchester M70 but there availability is something to be desired, which I think is probably due to McMillan not being able to supply enough A5's. If you want to wait there are numerous smiths that specialize in tactical builds, GA Precision being very well known.
Here is a picture of my SPR(top) along with my TRG 338 Lapua...both are 1/2 moa shooters.