Recommend buying one rated for 300 win mag so you can put it on everything. Rather than buy several suppressors.
If you want one exclusively for a bolt gun then buy whatever tickles your fancy. Surefire makes some pretty stubby little cans.
If You want one for semi-auto (AR) then buy the OSS. Blowback of poison gasses will soon be common knowledge. OSS has figured that out and has developed a suppressor design that will change the game in the next few years. Even DOD solicitations insist on a zero blowback capability.
Alot of vets. I know have respiratory and blood issues from breathing all the toxic blowback gasses cause by shooting suppressed semi-auto's.
On a bolt gun none of that matters. But on a semi-auto you can smell, taste, and feel the gasses in your face from a standard baffle type suppressor.
Check out silencershop.com They will walk you through the whole process.