Most hunting type 30 cal cans will have 5/8" "Hub" direct thread adapters. "Hub" is label for standard threads inside the can that accept either the direct thread barrel interface or any of a slough of muzzle devices to interface with the can.
You put a 1/2" to 5/8" adapter as was mentioned earlier or if your can allows, you can just swap up the hub to one with 1/2" threads rather than 5/8". Swapping the Hub is preferrable to me unless you have other rifles with 5/8" threads. One less case of tolerance stacking.
As far as what suppressors you should be looking at.. Theres a lot of options with different trade offs. From a performance standpoint, length, weight, suppression are probably the 3 biggest factors considered. Ti is a little more forgiving of different chemicals used to clean compared to steel. Steel cans can be more durable, heat up slower, typically less expensive, but heavier.
Some of the best current options balancing suppression, length, and weight: Dead Air Nomad XC, Otter Creek hydrogen S ti (available in 6.5 bore sometimes), and AB Raptor 8. Those options are all roughly 6.5" forward of the muzzle suppressors.
unknown suppressors is a new company with some intriguing options as well. Their OG model is an 8" suppressor but 4" of that goes around the barrel and 4" is in front of the barrel so it might be a nice option if you're wanting to keep a long barrel. They wont suppress quite as well as the 6"+ in front of the barrel cans.
In regards to 6.5 vs 30 cal suppressors, i'd get a 30 cal one personally to be more versatile. Bore size impact on suppression seems to vary based on application. IIRC, thunderbeast claimed roughly 2 db difference between their 6.5 and 30 cal ultra 7 cans when using 6.5 and smaller cartridges.
In general - the more powder burning, the more volume in a suppressor needed to suppress. What cartridge are you looking for?
