I've actually had this idea for a while, but I had forgotten about it because of the macro pack and public hack. The whole point of the macro pack is to combo a whole bunch of handy macros together so you don't need to open multiple programs to access them, but you can still only use 1 or 2 of them if you want, so that's why I keep adding new stuff to it.
This idea came around the same time as the quickscope (like half a year or more ago), but I dropped it in favor of the quickscope. This is one of my favorite ones, just because it handles a very annoying problem I run into when playing AVA: switching to your secondary.
The macro is designed to smooth out the process of switching to your secondary when you run out of bullets in your primary. It determines (mostly by guesswork) how many bullets you've shot so far, and if you run out of bullets, it switches to your secondary for you, allowing you to keep firing. You can turn it on and off, so you don't have to worry about it activating at bad times.
The only problem I have with it is the timing. I figured out that most guns (if I had to hazard a guess, I'd say 80% of the guns) can fire off their entire clip in about 3 seconds (excluding shotguns, snipers, pistols, w/e fires slow as hell or single shots). There's some discrepancies obviously, as some guns have bigger clips (PP-19), some guns fire slower (M14 EBR, AK200), but most guns can fire their whole clip in 3 seconds. I managed to get the 3 second timer working for guns I own, even accommodating for bursts (full-out fire was easier to time, but no-one does that), with error margins of like 2 to 3 shots not fired on slower ROF guns (M14 EBR and AK200) or guns with larger-than-normal-clip sizes (MegaCap guns like the Scar-L Gladiator and Sharks).
However, I could probably iron out those problems with a bit of fine tuning and a little input from the user (input the clip size, maybe ROF), but I don't want to if no-one would want this macro.
So would anyone like to see me make a switch-to-pistol macro in the next update? Even if just 1 person wants it, I'll make it for them, I just need to know I'm not wasting my time.