Last November I did a side-by-side comparison between two unmodified Remington 700Ps
(Mfg website link). One in 300 Winchester Magnum, and another in 308 Winchester. Both rifles are fitted with Leupold quick-detach mounts and Harris bipods.
Differences: 300 WM has two-piece base & a Leupold 4.5-14x Tactical with mil dot reticle (Leupold #49208). The 308 has one-piece scope base and is temporarily fitted with an early 1980s Tasco 3x9 scope until I get a better replacement.
Here's the 700P in 300 WM:
The targets (below) enlarge with a click. All were shot at 100 yards.
The test really wasn't scientific by any means, the 300 WM ammo was exclusively hand loads and all the 308 was South American ball or Chinese steel case 308 ball from the early 90s. All targets are exactly 8.5 by 11 inches. Rifles were supported with bipods only.
The 300:
Silhouette. Couldn't really see the geometric center, at 100 yards it looks like the black blob in the top left corner:
And I'm trying to pull a Vassili Zaitsev here shooting where the scope would be:
And the 308 Win:
-
Black dot in center is exactly 1" diameter.
And the silhouette:
Even with the scope and ammunition in favor of the 300 WM, the 308 still has respectable performance.
As you can see, the 700 won't disappoint you, particularly a P/PSS model.