How and when do I unlock these? I’ve unlocked the regular version of the BR. I’ve picked up a few of the long shots but I don’t know how or when people have gotten them. Any insight on this?
through the REQ system. Everything is unlocked throughout it. By what you are asking I am guessing it is only able to be grabbed inside the silver and the gold onces
all of the unlocks come through RNG req system
req system or scavenging dead guys, only way to get them
For Loadout weapons (Magnum, AR, BR, DMR, SMG), you only variants like you mentioned through REQs. Once you unlock them, you can use them every time you spawn, supposing the match has allowed high enough REQ levels. For example, to use the Recon AR with bayonet, you need to wait until Palmer says “Level 8 REQs available.”