Huh. I got mine really early (not sure where). And since my varmint rifle wasn't modded (the Goodsprings shop somehow bugged and lost the scope/silencer), it became my default long-range/rifle weapon. Found it looooong before I ever got my hands on a Cowboy Repeater, so I used it alot. Heck, I'm still carrying the thing for long shots at weak stuff. Not going to waste my Trail Carbine's .44 ammo on low armor dudes....
(But, then, I carry a variety of guns. Right now I've got 9 and 10mm pistols, 10mm smg, service rifle, trail carbine, and thump-thump. I should probably stash the grenade launcher, I never manage to find a spot to use it.
)
Edit: also, the service rifle looks alot more "professional soldier" running around in my 1st Recon Beret, sunglasses, and Reinforced leather armor.