My son and I were active in Airsoft battles every weekend back in 2007-2008. It was a really good time: outdoor activities, reinforced how to work within a team/structured environment, and it was great Father and Son bonding.
We didn't have blowbacks, though. He had a couple of springers, and I still have the AK74U electric that I used then.
Gonna have to look into that 1911 like you have. It's an excellent idea for training, like you said.