The ACR may be the talk of the town but don’t underestimate this 2-tapping monster. Learn everything you need in our XDefiant MK 20 SSR guide: How to unlock it, best attachments and loadout, and all camos.How to unlock the MK 20 SSR in XDefiantThe MK 20 SSR has no unlock requirements and is available to everyone from the start. This Marksman Rifle is deadly because it can kill in two shots at ridiculous ranges. You can use the default one without attachments if you wish, but the Marksman preset class provides a decent MK 20 SSR complete with a scope.You can’t choose your Secondary weapon with the preset class, but you can certainly get a feel for the rifle.Best Attachments for the MK 20 SSR in XDefiantAttachments take an obscene amount of time to unlock in XDefiant. That said, the MK 20 SSR is fine as long as you have a scope. You unlock the Reflex Sight at level 2, making the weapon much more useable. Here are the attachments I rec…