I am posting because I would like to check my own opinion/selections with some of those that have in field knowledge of what I only really have head knowledge of.
This is going to be a beat em'up hunting rifle that will be for inside of 500 yards primarily. I hunt Whitetail and Hog 95% of the time that I hunt big game.
I know this platform capable of 1000 yards for paper but on a regular basis, I am not going to be doing that at this point in time. This is going to be a long process, it won't be until next summer that I buy (gotta save up some scratch in my rat hole).

Ruger American Rifle in 308 Win (Currently own)

Wish List:
Swfa SS 6x42
Magpul Hunter American stock (releasing later this year)
Timney trigger (3 lbs just for safety reasons)

I don't want a 3 lb trigger on any rifle. You may be sacrificing a bit a accuracy by going that heavy.

Don't scrimp on a base and rings.

I am used to pretty heavy triggers but with the Timney that is an easy fix. It is user adjustable down to 1.5 lbs.

308 terminal ballistics on game at 300-500 yards are not that great. You'd be better off with a 6.5mm or 7mm projectile. I'd suggest a 7-08 or 6.5 CM

Swfa- 3x9 hd
Jury is still out on the magpul, personally they are ok with me
Timney at 2 lbs,
Don't cheap out on bases and rings

Just re-read OP post, didn't see that you already have the 308. Still a good round just don't expect too much out of it at distance. My 20" 308 sends 178 gr ELD-x handloads at mv of 2600. That gives 1885 fps at 500 yds with ~1400 ft-pds of energy.

Don't waste your money on the Magpul stock. Find a used B&C or H&S for the same price.

You are on the right track with your thinking. You might want to worry more about the bullet selection when you start to stretch the legs out on a rig. A heavier bullet will carry more energy down range. Then, practice, practice, practice.

Most of what you listed is just personal preference, and that's fine. Go with what you are comfortable with to have the best chance of good shot placement when that moment comes.

I have several rifles with fixed 6x (Leupold) scopes. Borrowing a friend's rifle, Remington 700 300 Weatherby, with a Leupold 6x42 I shot an eland at around 400 yards. I was the back up as the sun was about to set, not having a variable power was no hindrance. The 6x is plenty to aim and the field of view is enough the surrounding animals can be seen and don't just suddenly appear in the scope.
If you haven't already I would fire at 500 with whatever scope you have and make sure the rifle will group well enough. 308 is enough, for the far end of your range have a good laser rangefinder.

M

While I am a big fan of 6.5CM and 7MM I have a whole lotta respect for the .308 too. Last elk I saw shot at over a 1/4 mile was dropped instantly by a 308.....

http://www.longrangehunting.com/articles/308-winchester-1.php

Thank you all for thoughts, I really appreciate the feed back. I have been trying to figure out what I want to do with this rifle since I acquired it last November. The unfortunate thing is that there are only two after market stock you can get for a Ruger American. Boyd's and Magpul are the only offerings right now for a hunting package. Stocky's makes one in their own brand but its a bench rifle stock.I haven't checked McMillan in a while but they didn't have anything either.

What are your thoughts on the Boyd's stock? Specifically, the prairie hunter is the one I have been looking at.

I would look for a quality stock of some sort, H&S, B&C, Manners, McMillan, Graybull. Also invest in a quality range finder and spend time at the range shooting out to 500. Wind will play a factor at 500. Also use a quality bullet with a decent ballistic coefficient and you may want to look into custom ammo as you are reaching 1800fps with the 308 at 500 yards with alot of the factory ammo.

Replacing the stock may have problems due to the magazine. The bottom of the stock needs to match the contour of the mag. The tang safety may also be an issue, the inlet cut will weaken the wrist.
I doubt if manufactures like McMillan will make a dedicated pattern for a budget rifle.
Does the mag latch into the stock or an extension of the receiver?

M

The mag latches into the stock not the receiver.

Why not call it a 400 yard rifle and use that first hundred yards for sneaking up on em. And you might consider that velocity plays a greater role than energy in bullet expansion, many bullets that work perfectly at 500 yards might be a bit soft at closer ranges.

Uh, wut? Please illustrate the massive differences below at 300-500 yards.

6.5mm
143 gr. ELD-X
G-7 BC .314
MV 2800 fps

100 yards 0 wind, 2245 ft/ lbs.
200 yards .1 wind, 2013 ft/ lbs.
300 yards .2 wind, 1800 ft/ lbs.
400 yards .3 wind, 1605 ft/ lbs.
500 yards .4 wind, 1428 ft/ lbs.
600 yards .5 wind, 1266 ft/ lbs.
700 yards .6 wind, 1119 ft/ lbs.
800 yards .7 wind, 984 ft/ lbs.
900 yards .8 wind, 862 ft/ lbs.
1000 yards .9 wind, 751 ft/ lbs.

7mm-08
162 gr. ELD-X
G-7 BC .318
MV 2750 fps

100 yards, 0 wind, 2455 ft/ lbs.
200 yards, .1 wind, 2206 ft/ lbs.
300 yards, .2 wind, 1970 ft/ lbs.
400 yards, .3 wind, 1758 ft/ lbs.
500 yards, .4 wind, 1565 ft/ lbs.
600 yards, .5 wind, 1388 ft/ lbs.
700 yards, .6 wind, 1227 ft/ lbs.
800 yards, .7 wind, 1080 ft/ lbs.
900 yards, .8 wind, 946 ft/ lbs.
1000 yards, .9 wind, 825 ft/ lbs.

.308 Winchester
178 gr. ELD-X
G-7 BC .278
MV 2700 fps

100 yards, .1 wind, 2559 ft/ lbs.
200 yards, .2 wind, 2256 ft/ lbs.
300 yards, .3 wind, 1982 ft/ lbs.
400 yards, .4 wind, 1736 ft/ lbs.
500 yards, .5 wind, 1514 ft/ lbs.
600 yards, .6 wind, 1314 ft/ lbs.
700 yards, .7 wind, 1134 ft/ lbs.
800 yards, .9 wind, 972 ft/ lbs.
900 yards, 1.0 wind, 828 ft/ lbs.
1000 yards, 1.2 wind, 700 ft/ lbs.

It's about trying to keep supersonic to 1000, not the energy.

Of the 3 I'd go 6.5 CM 22"+ if you really want to shoot paper at 1000y with factory ammo.

Why does it matter if its supersonic at 1000 yards? He's only wanting to hunt at 500 or less.

And energy at 500 or less is important because he wants to hunt deer and hogs.

M

This.