Hi all, I was slugging my .270 bore to see what it was. I have a micrometer. The gun is a model 70 from the late 60's. The grooves are easy to measure even though it looks to be a five grooved barrel. My question is: how do you measure the actual bore dimension? I need to find the difference between the lands and the grooves so I can paper patch some boolits.The slug is so small I can't use my mic. I'm thinking maybe I will need to buy some pin gauges. How do you all do it? I have a dial caliper but that seems a little coarse. Anyway, thanks for any feedback, Gary