what you want to do is run a high impact hand cannon like Timur's, Ill Will, Thorn, TLW, get your pot shots on the guy while behind cover, then you want to swap to DN7 and without giving a -blam!- about ammo for it just spam it as you exit cover, I use it as a long range shotty and it works out pretty decent most of the time. if you get the drop on a guy you can effectively kill him fairly quick, a ram will obviously live through pretty much all 5 or 6 shots you have however thats where the high impact hc comes into play by shooting your target with the HC a couple times first you effectively negate their armor and shields in one engagement, you then follow up with impossibly high RoF sniper rounds which they will never expect and as their fallacy leads them to expect more inaccurate HC fire (especially on a map like pantheon where snipers will chance that you won't be able to hit them enough times to kill them) you spray them down with highly accurate shots and their draws drop in disbelief that they were killed by "the worst sniper in the game", using this tactic I've killed full on sunsinger, flame shield, radiant skin rams, after you negate their armor advantage you are home free to waste them ofc this method is highly circumstantial and will not work every single time and statistically you will fail more than you succeed however in my experience if you manage to kill a ram with all the extra health they usually rage quit after they die to you 2 or three more times.