Re: $500 max to spend what 308 bolt do you buy?
I bought a Rem 700 SPS-Varmint in .308 Win about 3 weeks ago for $579 before some sale discounts at Bass Pro...discounts that were worth $214. Also, Remington has a $40 rebate for this rifle. As stated above, Dick's still has the $549 deal.
Now some here and elsewhere on the internet like to slam Remmy. Yesterday I put together several 3-shot groups with that rifle, using a Harris 9"-13" bipod and a basic Caldwell rabbit ears rear bag, that measured 0.19" to 0.25" using my hand loads and some Federal Gold Medal Match. The optics were one of my Zeiss Conquest 3-9x40s with a Z-Plex reticle and Leupold STD rings and bases. My goal was to understand the capabilities of the action and barrel...I'm planning at the very least to replace the stock, but at the moment, everything is as it came out of the box.
Now a good custom build will produce a rifle that can generate those results consistently regardless of temperature, barrel heating, etc and, of course, Rem would never warrant that it's rifles will produce this kind of results. Nevertheless, this is a helluva rifle to start with. FWIW, I have 3 Rem 700s, this one, a stock SPS SS also in .308 Win and an XHR in .25-06. I have no mods yet on any of them...they haven't shown me that they need them for their current uses. The SPS SS will produce 0.35"-0.5" groups with my hand loads and the XHR will do 0.5"-0.75" groups with hand loads. The latter two Rems were $600 rifles.
For full disclosure, I also have a Savage 116 FHSAK and a Win M70 Extreme Weather, both in .30-06. Both produce 0.6" or somewhat better groups with my hand loads. All four .30 cal rifles will produce sub-MOA groups with Federal Gold Medal Match as well as with nearly all the bullets I use for hunting.
Net, net, in my experience and opinion any of these three brands will produce good results for starters with Rem and Savage being the easiest to customize. I'd recommend you wait on mods and spend your dough on lots of ammo and practice a whole bunch to learn your capabilities and needs.
I used to shoot a good bit of military high power matches and was very happy when my M1 Garands would deliver 2-3 MOA and my M1A SuperMatch would yield 1.5 MOA. I'm a n00b at LR precision shooting and haven't shot at longer than 600 yards yet. For the moment, what I've got works ok but I'll be investing a bit as I develop. However, good shooting technique and knowledge of your load's ballistics will take you a long way.
My $0.02 and YMMV.
FH