Blowing money or just having fun with a rifle?
There are several AR15 guns that we’ve seen come out that were basically a novelty. I wouldn’t trust some of the direct impingement 5.45×39 guns with my life because it’s just a flat out bad idea to expect a gun to run on ammo that dirty and in a firearm like an direct impingement AR15 for very long. Some of the differences in barrel life vary from firearm to firearm and the machining and matching of parts can mean the difference between a hobby gun and a combat firearm. From my experience putting a gun together properly is a big deal and i’ve seen many imported firearms just not cut it because the gunsmithing and assemble were so bad a firearm like a FNFAL can get a bad image.
Century Arms was notorious for making cheap AKs and FAL amongst other things and there have been some dud companies that made AR15s. AR15 rifle have improved and there are many guns that can become great hunting rifles with Bushmaster upper receivers that have the configuration that you might want for deer or varmint hunting. I have a Bushmaster XM15E2 that is the second firearm that I train new shooters to use. The iron sights on a carry handle and the long 20inch heavy barrel are very good training guns.