A few weeks back we featured an article from the folks who make the Annealing Made Perfect Induction Annealing Machine. In this follow-up report they dig deeper into case variations and how they impact the annealing process.
“Our Stage One report on the metallurgy of annealing was designed to cover the basics of brass cartridge annealing, and also to address a number of misconceptions on the subject. In Stage Two, we have again worked with independent metallurgy laboratories to establish:
- Why do different brands of the same cartridge case require different amounts of power to anneal correctly? Further to that question, why can there be lot to lot variation from the one manufacturer? To answer those questions, we again consulted with Andrew Ouwejan from Metlab Ltd.
- What factors influence consistent, repeatable neck tension? In Stage One of our tensile bullet pull tests, we established a baseline using no internal neck lube and no cleaning. We now start to explore different options, again using the services of Nick Casterton at Air New Zealand Gas Turbines Materials Testing.”