I'm having a very similar problem. I'm following almost exactly the same steps as outlined above, only I was actually able to hit a few MRAPS with the drone (despite the fact that it has a -terrible- time trying to target anything even with low difficulty settings... I have to swoop with 1-200m of the target to acquire it, then make another pass to take it out. It usually takes flying till with 100m for the missile to lock on fully).
Still, I have exactly the same issue with the artillery, the Blackfoot, etc.

My first attempt once I found out the helicopter was worse than useless was to actually allow the enemy tanks into the town and ambush them. They can't hit you if they can't see you, and they can't see you if you're 50m behind them with an AT launcher. But... allowing them into the town fails the mission.

I was smart in that I made sure several squad members and myself had AT missiles before starting the mission... But between the three of us (only one of which had them to begin with) we can only manage four MPRL AT rounds... not nearly enough. Especially since the other guys can't hit the broad side of a stadium -never mind a stupid barn!- with their launchers.

So let's some up:

1. The helicopter is worse than useless. It never even attempts to fire, let alone help.
2. The artillery doesn't always send rounds, and when it does it's WAAAY too late.
3. I should be able to allow enemy armor into the town in order to destroy it, then recapture the town. Just fixing this issue might allow us to at least proceed with the campaign.

I'm going to jump on and agree. I bought Arma 3 recently because I was looking for an FPS that was open-ended/sandbox instead of linear. I wanted something more realistic and the ballistics in this game looked very promising. I love movies like Shooter and really enjoy sniping. I love taking the time to set myself up so that I can take that one shot that makes all the difference.

I can't do that anymore. I was just playing the single-player campaign and was ecstatic to find a Lynx just now (my first time able to play since patch). Previously I was able to hit targets ~1000m fairly consistently (after practicing it for several hours). Today I couldn't hit a target, while lying prone and fully rested, at 200 meters. For real?!

I really like the boot camp, though I feel it really could be longer... but this excessive gun sway is almost game-breaking for someone who likes to snipe (me!). I also have several friends who I routinely play with who feel the same way. PLEASE put the sway back where it was!