Greetings,
I would like to share a real life experience that may help you.
I attended 2 Appleseeds with my wife.
Each student shoots about 1000-1200 rounds in those 2 days.
The maximum you shoot per session is 13 rounds (red coat) and the minimum is 5 rounds (square).
The first Appleseed we both brought our RRA CAR-15 and used Lancer L5 magazines. First day: no failure at all. We thorougly cleaned the rifles after the first day. Second day: Around half day my wife got light strikes. She pulled out the bolt carrier, sprayed break free cleaned the firing pin channel and she was good to go until the end of the day. We both had one double feed the second day. We used my reloads (55 grains SP Hornady, PMC bronze brass and 25.1 grains Ramshot Tac.
The second Appleseed she brought her RRA CAR-15 and I brought my SIG-556.
She shot my reloads and I shot Wolf 55 grains Military classic. We both used Lancer L5 magazines. She got 2 double feed during the 2 days and she got one round that did not go into battery entirely and we had to be 2 men to pull on the charging handle. After that she used a chamber brush to thoroughly clean the chamber. She cleaned her gun after the first day like the previous Appleseed. I got one double feed with my SIG 556. No other malfunction.
I did not clean the SIG556 after the first day. After the 2 days, there was just a little bit of powder residue in the lower, around the chamber there was a bunch of red residue that is found around the primer. The end of the piston rod was full of crud, but a good scrape with my cutter removed all of it.
Bottom line: my SIG 556 was way less maintenance and I got only one malfunction... using crappy very dirty ammo.
oh! but I still love my ARs and prefer to shoot them still over the SIG556.
Thank you