It depends on playstyle. I used the hunting rifle a lot at the beginning for snapshots reactions, but now it's far superior to train reactions in melee. And although having a weapon that can react well is nice, the hunting rifle is a bit underpowered when you take out its one advantage of training reactions.
As for other ones, usually once I get them, 1-2 Kustom Snipin' Guns make it on my lineup, but it's hard for them to compete with HMGs really. They get screwed by the RNG (small drift causing them to hit terrain, small roll meaning no damage is done) and by the wonky projectile paths (where the game lets you fire even though you can't hit). Both of these are compensated for by the HMG (and later Vulcan) and their large number of shots. You can get ~40-50% to hit with those, and with so many shots, that's more hits and more damage than the snipers can do, while also being able to blow out intervening terrain (you can even force fire through light cover pretty reliably). So my snipers get replaced by HMGs or Vulcans pretty quickly.
What snipers would need is a return for all of them to being able to react (real and/or movie snipers will get you within seconds of you peaking your head out of cover), maybe with a slightly worse damage bonus on snap shots than aimed shots (but I don't think that distinction is possible). In fact, I'd actually give snipers a large bonus accuracy for kneeling, to represent that you need to setup if you want to hit something. Then the snapshot would become useful again, and it doesn't really matter for the aimed shot since that one is usually well above 100% any ways and there's no difference between 100% and 160%.