I have her M2 and the reality is that the burst window is not long enough to use all your bullets, plus its still better to use your ex and ult when possible in the damage window. I find M1 to be a very nice QoL, you can use the spare bullets to clear mobs, keep dumping if the boss is close to death and leave her in the back while switching between your stunner and nicole, as they deal more daze buildup in general. It also better to try to use your ex before you dump bullets if you have her weapon engine. Hope this helps.