stallones: glad you have developed methods that work for you. sadly, others have not. the results of their ignorance and experimentation, have created a fair supply of parts guns... a question: if you accept the fact that shotgun receiver metallurgy varies from manufacturer to manufacturer and even varies within manufacturer, depending on period, how do you develop a spec for a receiver you have never done before? it would seem to me, all you can do is guess?

keep it simple and keep it safe...