2 ms·
All bullets will tumble when they change media like that, they do a 180 and if in the body long enough will exit rearwards. There's enough bullshit in the link
by hga 11y ago
All bullets will tumble when they change media like that, they do a 180 and if in the body long enough will exit rearwards.
There's enough bullshit in the link you reference that it should be entirely ignored, the twist rate pertains to getting the bullet to spin fast enough to be stabilized in the air, it's not going to significantly affect the stability once it changes media. It's been decreased, bullets are spun faster, because we've adopted a heavier and disproportionately longer round (has a soft steel penetrating capsule), and the particularly long tracer version requires a 1:7 twist rate.
Cavitation, which causes the effect called temporary stretch cavity, is if you believe Dr. Martin Fackler, not a major wounding mechanism, most tissue will snap back without major effects. Permanent crush cavity is what counts.
This is not the general understanding when the round was adopted, it's what Facker found out after a lot of surgery in Vietnam lead to a career in wound ballistics and shooting a lot of blocks of calibrated gelatin etc. to figure out what actually happens.
- 67726e 11y agoSource?
- hga 11y agoIn particular Fackler's works that are available on the net, but I'm under the impression that's general knowledge, plus the basic physics. Now that I think about it I'm not sure what the official story is with expanding bullets, which are not under discussion here, but I can't see how adding drag to the lighter end of the bullet will change this. And of course it'll depend on profile, I'm talking about spitzer rifle bullets, a putative fully jacketed wadcutter, a simple cylinder, wouldn't have any reason to swap ends.