Getting started reloading for M4/AR15 - advice requested

[BravoGolf59]

I have been reloading for bolt action rifle for a while and feel like I understand that. I recently participated in a club-level carbine match and really enjoyed it. If I could reload ammo for it, I could probably afford to participate each month, and this leads to the questions.

It takes approximately 120 rounds for a match. Most targets are 15-20 yds. or less, with some 50 yd. targets thrown in. I used AE223H, which seemed to work well and not have the recoil of XM193.

My big question is... [strikeout]how can I load for reasonable accuracy and be able to use mixed cases?[/strikeout]

Really, my question is what process (as in load development) do I use to arrive at the best load that works for mixed cases and is not dangerous? I was not asking what press to use!

I have several 20 round boxes of Remington, Winchester, Federal, Hornady, Privi, etc. fired cases. I also have several Lake City cases separated by year. Some of the LC range in quantities from 5, 10, 20, up to 50 to 80 for a given year.

Additionally, I have Hornady 55gr. FMJBTs to use, and probably Hodgdon H322 powder as my TAC is getting low.

I appreciate and look forward to your advice!