Your first attempts at gunslinging in Lockdown have gone much far better than any of mine ever will, but there are some things that you can work on, and will improve on over time. I am by no means a gunner myself, but I can provide some input.

Mobility is a gunners' best tool, whether they be Striker, Recon, or Guardian. Always stay on the move, and don't strafe in predictable circle patterns. Any sword-fighter with half a mind can cut off a gunner walking in a predictable arc. I recommend watching Blueflood's series of YouTube videos on Lockdown, as they demonstrate a wide array of strategies that involve mainly gunning and running. A gunner is only alive so long as they stay on the move.

A good rule of thumb is to avoid doing a charge point blank unless your target has no clue of your presence, like you are south of them and you are hidden by the camera angle. If someone coming straight at you from the front, and you're still charging, let go of a standard shot, and hope that your Alchemer gives you a lucky Shock proc. Luck is a major factor when it comes to status Alchemers, so be wise to take full advantage of that.

You spend an awful amount of time walking around holding a charge, staying away from the capture points. I personally would advise against staying at a single point holding a charge for too long if there are other capture points to take. In the time you spend walking holding that charge and waiting for someone, you could have stopped charging and striker-boosted to the cap point on the other side of the map.

Call me crazy, but I do believe at one point or another I saw the Auto Target cursor. Contrary to popular belief, Auto Target is a hinderance than a help when it comes to gunning. It's up to you if you want to keep it on (If you even have it on in the first place), but keep in mind that you might just find yourself firing off in the wrong direction even if you try to predict someone's path.