The problem is not the castle nut, it is the fact that they machined down the boss on the lower to much. Even more of a concern is that If you aren't careful and remember to really lift up on the charging handle, it hits the stock and rips the handle out of your fingers (painful). I have compared this to six other AR 15 lowers. I can put the Ruger upper on other lowers and there is no contact, put any other upper on the Ruger lower and they will all hit the castle nut and stock. I sent the photos to Ruger and without hesitation they wanted the firearm back. They received the firearm on Monday, so now I wait.
I have never been bothered by normal wear and tear, but I don't like buying a new firearm and finding machining errors. Luckily Ruger has great customer service, so I am not worried about it at all. My original question was to see if other Ruger 556's got out with this issue, I already knew it was not normal, this isn't my first AR. I should have worded the first post better. I do appreciate everyone's perspective and I'm glad to be part of this forum.
Last edited by AR GRIFF; March 14th, 2017 at 11:24 AM.