For the vast majority of AR owners the wear difference between the two of them really will not matter. Most people just do not shoot enough rounds to get into the area where this would come into play. If you happen to be in that group of people who measures your round count in thousands, then yes it can be important. BUT we are discussing the literally cheapest blasting ammo available. I suspect we aren't dealing with high end precision target rifles. Those guys would be sorely disappointed with the accuracy of this grade of ammo and they toss barrels long before these wear issues would ever appear. The cost savings are more than enough to replace a barrel, upper, or entire gun after 10k+ rounds.