I have 4 new neighbors across the highway and would like to know what is a good load for my 18" rifle gas .223 AR that would take a bit off the report but still function. Can't find very much at all about mild AR friendly loads. Everyone is pushing them to the max. Would a 20" barrel give me more dwell time for the lower pressured gases to work the bolt? I actually have some H4895. Looking for a load that is 221 fireball power but functions in a AR. I can use a lightweight bolt/buffer if that would help.