My initial thought upon reading the thread title was: "Why would you hunt a Tiger with a LR-308?"
I've got an Izhmash Tigr in .308 with a 22 1/4" barrel and SVDS-style stock. Apart from the occasional lucky 3 or 4 shot group, it’s no sub-MOA rifle. Last year, I got to shoot it at a 520 yards match, but one of the screws on the side mount worked loose, so I can’t really tell you how accurate it is at these distances.
However, I’ve read an interesting article in a German gun magazine. They did a comparison between an original SVD, a Tigr in 7.62x54R, and two different Tigrs in .308.
The SVD and the Tigr in 7.62x54R were capable of 10-shot 1.5 MOA groups at 100 m with factory ammunition. This Tigr even produced a sub-MOA group with corrosive surplus FMJ if you discount one flyer. (The Tigrs in .308 were a tad less accurate.)
I’ve read an article on the LR-308A3 in another German gun magazine. The best 5-shot group from their LR-308A3 with an 18” barrel was 1.2 MOA at 100 m (well sub-MOA if you discount one flyer), but the rifle did worse with most brands of ammo. The Remington R-25 (which should be pretty much identical) scored a little better for some reason.
All by all, I would think that both guns are fairly evenly matched in terms of accuracy, although I would tend give the edge to the LR-308.
In terms of practical accuracy, the Tigr suffers a little because it doesn’t have a free floated barrel. Depending on the way you rest the rifle, your point of impact may vary, both in my experience and according to the aforementioned article. I have the suspicion that mine even loses some of its accuracy if I rest it on the front part of the handguard.
I don't know if the LR-308 suffers from the same problem if you don't have a free float tube.