Is that mod the Unlimited Companions one? And what was wrong with the Cowboy Repeater? Thanks.

No, I use one called Improved Companions w/CHA stat factors. But does essentially the same thing.
Cowboy repeater...someone got to that one first. Only for me it wasn't a second...it was more like I'd freeze for 10 seconds. It affected my companions if I gave them those weapons, as well.
Oh, lol...Sniper Rifle lovers are going to rage.
Only if they haven't tried it first. It's really not that bad....I can still one shot most things (I mean, deathclaws are not the entire enemy population...) while crouched/sneak critical, and if your crit chance is high, no big deal. Now in terms of being able to use it like a shotgun as you backpedal away from a deathclaw...probably won't be as good for that, but it isn't a terrible weapon for that either. the fire rate doesn't seem slower, so I like that.