Operating Systems 301: Introduction to Advanced Concepts

So far we’ve looked at the most basic concepts in firearms operating mechanisms as part of the 101 series of posts, and some more advanced concepts like locking and bolt configuration in the 201 level entries. However, there is a whole lot more depth to the subject, so much that the advanced 301 level discussions will really only be able to scratch the surface. Before we start talking about these subjects though, be forewarned: So far I have avoided including any serious math in the 101 and 201 level posts, but we will have to tackle some math as we delve deeper into how these weapons really work.

You can breathe easily for now, however, as this will only be an introduction to the 301 series as a whole. First, let’s ask why does Nate think he knows all this stuff? I haven’t been an engineer working in the industry, but I have read a few books on the subject, and supplemented that by critically examining new and different firearms when I come across them. Books and other written resources are absolutely crucial to having a sophisticated understanding of the mechanics of small arms, and two of the volumes that I most highly recommend are Technical Notes: Small Arms Weapons Design by John G. Rocha, and the extremely comprehensive  volume by George M. Chinn called The Machine Gun (duplicate here). If you are interested in further reading beyond these two, then I also recommend taking a looking at Hognose’s gun design resources page at his website, WeaponsMan.com.

What’s in the pipeline for 301-level posts? Stay tuned, and learn about everything from the blowback equation, to the concept of “underlug”, to what mass ratio is, and why it’s so important for locked-breech automatic firearms!

Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. In addition to contributing to The Firearm Blog, he runs 196,800 Revolutions Per Minute, a blog devoted to modern small arms design and theory. He is also the author of the original web serial Heartblood, which is being updated and edited regularly. He can be reached via email at [email protected]


  • PK

    I also have suggestions if you’d like a list of resources for cannons and tank guns and similar, in terms of engineering the barrel, breech, bore evacuator, and brake, then of course all about the various mechanisms (single/manual, single/auto-eject, mag-fed semi/full, belt fed, linkless feed, autofeeder turret, and on and on) and how to design them, what’s been tried and hasn’t worked, what works well but needs tinkering, what is known-good as far as designs…

    If you want to dig to that depth, eventually, in this subject.