RE: Barrel life
I have a heavey barrel 223 that has close to 10000 rnds and still going strong . Any of the cal. that you listed if you don't shoot it hot , clean it and just take care of it will last many thou. rnd . Or you can shoot it so hot that you burn your self ,don't clean it or worse abuse it while you clean it , the barrel may last 1000 rnds . Take care of it and it will take care of you.