Saturday, October 8, 2011

The Futility of Gun Control

Borepatch links to Popehat on the futility of gun control with the advent of cheap, home-based CNC and 3D printing.  Popehat brings the smart - and a pretty decent James Burke (Connections, The Day the Universe Changed) impression.
And speaking of technology-driven emancipation, we arrive at the thesis statement for today’s rant: the end of gun control is not politically or culturally driven, but was a historical inevitability that was written into the book of destiny by 1810, when Joseph Jacquard started using punched cards to control weaving patterns on his looms and when the practice of chucking rotary cutters into lathe headstocks was adopted en masse at water powered factories in Western Massachusetts in response to British attempts to confiscate American civilian-owned firearms.
Cool, but more up my alley:
…or, if you prefer metal over plastic, download the plans for a full AR-15 lower that you can crank out with your fresh-from-the-box $1k Sherline CNC milling machine and $15 worth of aluminum, then kit it out with $410 worth of barrel, shoulder stock, and such.
For quite some time, I've had a link on the right column to the story of my AR-15 made from an aluminum casting and mail-ordered parts.   This was an 80% lower from Colfax Tactical, not small pieces of aluminum plate, but the approach Popehat links to looks like it could be even more fun.  Yes, there's more milling and shaping with those pdf drawings than the casting, but nothing that is too hard for a home machinist, even with that "$1k Sherline CNC milling machine".  The key is to work thoughtfully - "there is no white out for metal" - and realize you can't take off as much metal with this little mill as you could with a monster full-sized mill.  This is where CNC shines, it can take repetitive light cuts all day long without getting bored and counting thousandths wrong on a dial.  I bought my CNC mill used for around $300, but it needed quite a bit of work and another couple of hundred $$ to get it working properly. Like all hobbies, it's easy to get started, but you can buy accessories and improvements long past any sanity.  Currently, it's a mix of Sherline and A2Z CNC parts - one of the cottage industries that has sprung up to supply home shop machinists. 

There's much discussion in the comments to Popehat's piece on making the barrels.  Barrels are tough for a couple of reasons: first, drilling a hole that long which stays centered in the barrel and doesn't wander is not trivial, but harder than that is rifling.  Rifling a barrel requires pushing a cutting tool into the barrel while twisting at the required rate.  Obviously, people have been doing it since 1500s, but it's not easy for a small shop machinist to do.  Today, barrels are consumable commodity items; I get ads for replacement barrels almost monthly.  If concerned, buy some spares. 

That Popehat post has a photo of a 3D printed magazine that raises an interesting question.  What if one could print the plastic parts of their polymer pistol and CNC machine the metal parts?  All that would be left would be to buy some springs and a few other parts, then assemble it all.  That day is coming, too.


  1. "No white-out for metal"


    Sure there is. It's marketed under the brand name "Oops. Damn."


  2. No white out for metal...not entirely true. As the tool maker at a place I once worked told our welder with a smile..."ever since I found out how easy you can put it back on, I haven't had to be so careful how I take it off".. ;^)

  3. Anon - that's real art! But point taken, a good welder can put extra metal back. I guess I'm concerned about alloys like 6061T-6 ("aircraft aluminum") or the 7000 series, which use heat treatment, and whether the metal added back is as good as the original stock.

    I claim no skills in welding. So far, I'm only moderately successful taking metal off, not at all putting it back.