My 1 year old SR556 rifle had very severe buffer tube wear after 1500 rounds. Sent it to Ruger on 12/17, received it back yesterday (I guess they don't take much time off during the holidays). They replaced: upper receiver, buffer tube & retainer, bolt carrier group, safety & detent, repaired: chamber & feed ramps. All at NO CHARGE! I am extremely impressed with the speed and thoroughness of their customer service. Planning to range test today. Thank you Ruger!