My AR is a heavy barrelled, fast twist rate. It needs heavier bullets. I can buy inexpensive 55 grain ammo for around $11-$12 a box, but it has very mixed results. It might shoot 3 in a row into 3/4" and then throw one 2" off that group. With $38 a box 69 gr match ammo, they will all shoot into 3/4", but that price is obscene. With reloads and decent bullets, I can load them for a little less than the cheap ammo using quality bullets, and shoot 10 shots into an inch without a single flyer. So do I save money, yes and no. Only really when I compare to decent ammo.
I have some 150 gr hornady 308 bullets already loaded with 42 or 43 grains of IMR 4895 that I use in my bolt action rifle. I use it for hunting, and it shoots superbly. Last time I tested it at the range, I fired one shot, walked to the target and covered the hole with tape. Fired another shot and didn't understand what I saw. Walked to the target and observed a hole in the tape, right through the first hole. Its nowhere but downhill from there. Some luck involved, but at the same time, my Tikka bolt action rifle is giving me consistently good results with a a wide range of powder charges.