I worked in a gun shop doing repairs, refinishing, and custom work for a decade. They were already using nitride from H&M prior to my arrival for its corrosion resistance. I had never heard of it before I went to work for them and as far as I can recall Blaser was about the only rifle manufacturer using it.
Standard procedure was to strip everything down to the last pin. Separate parts into groups to go or not. Over time we refined our go no go list as experience was gained. No springs, no roll pins, some parts had to be a judgement call because very thin parts could end up warped or brittle IE some extractors, mag boxes on WBY single feeds for the big cases were very thin and prone to getting wonky. Very small screws could sometimes become brittle and half the head would break off where the flat slot was cut in them, we had plenty of replacements on hand and just viewed them as a consumable.
After the two aforementioned receivers cracked we called and talked with them and together decided that it likely had to do with very tightly fitted threads and the different expansion rates between the barrels and receivers. I also saw a couple Remington recoil lugs crack through the thinnest part when the barrels weren’t pull, same issue I’m sure.
After bead blasting and separating everything our shipping department would wrap parts in paper towels and make a checklist as they went. Box everything up and send it off. Week or two and everything would return finished and soaked in oil in plastic bags. Wipe down and reassemble, test feed and fire before calling customer to come pick it up.
I have been out of the business for 10 years now so I’m sure some things may have changed. I still feel that it’s the best finish going for a serious hunting rifle.
