If I’m going to slug my m3 barrel is it the choke measurement that I’m concerned about or the measurement before the slug goes through the choke? Barrel is the heavy slug liner.
I dont know about a choked barrel but you would probably want to start .001 over the diameter you get when slugging the barrel. I would think a choked barrel would be the same.
I think you will want your slug equal to or slightly larger than groove diameter of the barrel before the choke. It will take some experimentation. The measurement might eliminate some that are obviously too small.
Ever wonder how to slug a barrel? Here’s a barrel slugging video tutorial https://m.youtube.com/watch?v=2lMp_nahuMI
www.airgunnation.com
Here’s a thread on slugging what I assume is an Impact barrel https://www.airgunnation.com/threads/i-slugged-my-new-800mm-barrel-in-22.1259632/ Not much in this particular thread, but maybe you can reach out to some of the respondents or the original poster with further questions. You can also likely find more posts by conducting an AGN search concerning “slugging a barrel.”