Author Topic: Smack Down & Beating a dead horse  (Read 90 times)

Alan

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Smack Down & Beating a dead horse
« on: July 05, 2018, 09:57:51 AM »
Hajimoto recently posted another chipper smack down (http://airgunguild.com/hashimoto/chipmunk-smack-shot-3-(video)/), which got me thinking (maybe not a good thing!). As alluded to in my post, as air gunners, we seldom ‘see’ the actual hit, often described as ‘Red Mist’. Nonetheless, it is still there if we had the means to view it. I digress.

Internal ballistics is a well-known science, as is external ballistics. Whether we’re speaking of airguns or firearms, similar (and complicated) arithmetic is used to achieve efficiency, velocity, and accuracy. Sometimes the results only give you one or two of these goals, but seldom all three. Just ask air gunner extraordinaire Bob Sterne how difficult this can be!

To get to the point; I have always had an interest in terminal ballistics. That’s what happens after a projectile hits its target (Red Mist?). One of the better on-line explanations comes from Hornady (https://www.hornady.com/team-hornady/ballistic-calculators/ballistic-resources/). But the explanations therein, are written as if generated by a firearm. But we as air gunners have both drawbacks and advantages over a firearm with respect to terminal ballistics. Once again I digress.

I’m sort of on shaky ground here, because my experiences with casting lead bullets is limited. I’ve always believed that Linotype metal, an alloy of 4% tin, and 11% antimony, made the best cast bullets, at least for firearms. I suspect this alloy is way too hard for use in airguns. Based on Bob Sterne’s comments, an alloy of 2.5% tin (≈40:1) is about right for our use. But is it?

Some years back, one of my shooting group of friends tried duplexing cast bullets. Wherein the nose portion was pure lead, and the base section cast with Linotype metal. I’m sure that wasn’t an easy task. I suspect it wouldn’t be easy swaging them either. But what about using a 3D printer? The process is called direct metal, laser sintering (DMLS). If they can use titanium and aluminum, no reason they can’t use lead!

Getting back to the point, the hardness of the lead in pellets is partially responsible for the three goals I mentioned before—efficiency, velocity, and accuracy. But it is also a major factor in terminal ballistics performance. In this case, softer, pure lead, is better. I’m of the opinion that we haven’t reached the pinnacle of airgun bullets or pellets, cast, bought, swaged, or 3D printed! I’m just wondering when the next major, quantum leap will occur?


By the way, any and every body is welcome to comment.
« Last Edit: July 06, 2018, 01:02:16 PM by Alan »


  • Roswell, New Mexico
Alan

I have an Omega compressor. If you're a fellow Guild member, and you pass through Roswell, NM, I'll fill your portable tank as a courtesy.