I owned a Grade 1E NID 12-gauge in the 441,xxx range with 28-inch barrels marked 2 and 4. It was way over-bore -- .749" left and .744 right. Chokes were .009" right and .033" left. My 12-gauge 4E Skeet with all the bells & whistles marked S and S has bores .730" left and .729" right with chokes .016" left and .009" right. Going through my notes on the various NIDs I've owned in all gauges, I find the guns made 1935 and earlier are all over-bore while those made 1936 and later within a thou or two of true.
