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Better than I expected, too. Apparently that load shoots pretty well. Of course, a heavy revolver with a 6" barrel helps considerably. Probably should have stuck with the snubby, but I wanted every advantage for srt8wal's "Gold Dot Challenge."Quote:
Originally Posted by onelight
There didn't seem to be as much vertical dispersion as I expected. With both bullets cutting identical holes, maybe it's just harder to see. In retrospect, I wish I fired one of those targets at 25 yards. Other loads, wadcutter/truncated cone combos, had about 12" of vertical dispersion between front and back bullets at 25 yards. The two wadcutter load might be better.
This is exactly what I was seeing for grouping from my 642 although my loads were lighter. 2 each 75 grain WC with a light loads of claysQuote:
Originally Posted by pettypace
my 1873 was putting a little tighter group at that distance. I need to machine down my H&G 50 so I can start making more of those little wadcutters.
Is that to point of aim? If so, I think you may have something. Now stretch it out to 25 ;-)Quote:
Originally Posted by pettypace
Must be close to POI. Tired old eyes and a fifteen year old prescription on my googles make the sights pretty blurry. But I was trying to maintain a 6 o'clock hold on the 10 ring. Also, haven't fired the 38/44 for decades. No telling where that was last sighted to -- but probably for a 6 o'clock hold on a 25 yard timed and rapid fire target.Quote:
Originally Posted by str8wal
Some while back I made .38 Special double loads by the simple expedient of hacksawing a double ended wadcutter in two. A simple wooden jig to hold the bullet and position the saw made this easy, and a couple of swipes of the cut surface across a 180 grit sanding block smoothed things up. "Wads" cut from typing paper with a sharpened cartridge case were placed between the two, which I then ran through the lube sizer and loaded up. At 30 feet my J frame printed them in about an 8" pattern, with the majority clustered within half of that. Never persisted in this, as I was just scratching an itch, and would much rather rely on the superior accuracy and deeper penetration of an unaltered single projectile.
I love it! where there is a will, there is a way. And all that.Quote:
Originally Posted by Bill*B
So, you must have ended up with wadcutters just over 70 grains. Did you ever actually measure penetration? After several rounds of gel tests, I'm thinking that under-penetration is not a problem within any range where the two projectiles hit close enough together. I'm not sure, yet, just how close is "close enough."
At Wednesday's Snubbyfest, a shooting buddy set up his cell phone on a tripod next to the ballistic gel. The plan was to get a video as I emptied a cylinder of two projectile loads into the gel about as fast as I could and be more or less sure of a solid hit. Here are some still shots from the video:
Attachment 241388
The picture above shows the gel the instant before the first shot hits. Note the faint, almost horizontal line extending from the left side of the front bumper of the gray pickup. That's the streak of the two projectiles heading for the gel.
Attachment 241389
The picture above is the first frame showing the two projectiles of the first shot in the gel. Even with the poor picture quality from an old cell phone, it's clear that the two projectiles have created a single temporary cavity from which they separate after about 12" of penetration.
I don't know if anyone has quantified just how much of a handgun bullet's kinetic energy is "wasted" in creating the temporary cavity. My guess is that it's a significant amount of the original muzzle energy. So, it's not hard to imagine that two projectiles "sharing" the same temporary cavity would waste less energy than if they each had to create their own temporary cavity. Of course, that would leave more energy available for deeper penetration than the Schwartz "expedient equation" predicts for the single projectile.
Attachment 241390
The picture above shows one of the projectiles from the first shot just as it exits the gel. Look closely just below the rear tire of the tractor in the background. There's a faint white horizontal streak that appears to be about 2" long. That streak is one of the 105 grain wadcutters exiting the gel after 22" of penetration.
Attachment 241392
Here's a frame of the first shot after the temporary cavity has collapsed. It's clear that the two projectiles began to separate before entering the second 11" block of gel. I haven't dissected the gel block yet. But I might be able to tell if it was a front or back bullet that exited the gel.
I would wonder if any significant energy is “wasted” making a temporary cavity in a human target. Due to the more resistive action of the tissue having a connective component which gelatin does not. Depending upon what is struck of course.
The swelling one sees in gelatin from handgun bullet passage appears to have no effect on actual animal tissue, if it even occurs at all. I have double lunged several deer with 45 ACP 185 JHP at 1200 fps from a 625-3 revolver and the hole through lung tissue would admit maybe two man sized fingers side by side. The relatively fragile lung tissue had no damage outside that.
A 452423 traveling 950 fps left a similar to slightly smaller hole. For deer hunting I am not keen on leaving a hole of any significantly smaller size, as in my opinion the time for the deer to expire would be inhumanely lengthened.
That is not exactly rationale relevant to shooting a bad guy we just want to go away but it provides some context.
pettypace, very interesting studies! No, I never measured the penetration of my crude "double" loads.
I don't doubt that handgun wounds produce temporary cavitation in animate tissue much as they do in organic ballistic gelatin. How much permanent damage that temporary cavitation does in animate tissue depends on the tissue's ability to stretch without exceeding its elastic limits. This Fackler quote suggests that lung tissue is not as "fragile" as it appears:Quote:
Originally Posted by 35remington
Cavitation is nothing more than a transient displacement of tissue, a stretch, a localized "blunt trauma." It is not surprising that elastic tissues such as bowel wall, lung, and muscle are relatively resistant to being damaged by this stretch, while solid organs such as liver are not. (from "WHAT'S WRONG WITH THE WOUND BALLISTICS LITERATURE, AND WHY" by M.L. Fackler, M.D., Letterman Army Institute of Research, Division of Military Trauma Research, Presidio of San Francisco, California 94219, Institute Report No. 239, July 1987.)
There's a youtube clip of a guy shooting himself in the leg with .45 hardball. In the slow motion section of the clip, I believe you can almost see the temporary cavitation through the pant leg.
At any rate, what I meant by "wasted energy" in my previous post was something like "energy expended that in no way contributes to bullet penetration." I was just throwing out an idea as a possible explanation for the fact that the two-projectile loads I've tested in Clear Ballistic gel seem to consistently exceed the penetration predicted by both Schwartz and MacPherson.
Bill*B -- when I first started on this two-projectile kick, I was impressed with Hatcher's energy-based formula for pine board penetration. So, I figured I needed light weight wadcutters at high velocity for any hope of achieving adequate penetration. I've since learned that heavier bullets at lower velocity give more reliable penetration. If I had had your ingenuity, I might have saved myself the price of a NOE 70 grain WC mould.Quote:
Originally Posted by Bill*B
Lung tissue damage is very markedly different when going from pistol caliber velocities to rifle caliber velocities. A centered lung strike with a 270, 308 or even something like a 30-30 or 35 Remington leaves little intact lung left. All that is found is chunks floating in blood purée. Under these conditions the lungs are fragile, more so than an organ consisting of solid muscle like the heart.
Not that a heart hit by a bullet is done any good.
Lung tissue, we could therefore agree, is very fragile when hit by a rifle bullet, but evidences much less damage when hit by a pistol bullet. In terms of density it is very light, certainly. The “temporary cavitation effect” at pistol velocities on lung tissue appears to be pretty much zero or at best very attenuated. There is a relatively small permanent channel and no damage adjacent to the area of missing tissue. With rifles there is simply a lot of missing tissue.
Since lungs are a primary target on “upper body mass” shots due to their size, and humans are more likely to be “single lunged” by a bullet strike, the need to shoot again when firing a pistol is understood by most to be very likely if incapacitation is desired in a reasonable time.
The double lunged deer went anywhere from 40 to 80 yards after being hit. Sort of a reality check.
35remington -- here are a couple of Fackler's "wound profiles" that clearly illustrate the point you've made about the difference between the temporary cavities from a handgun vs a rifle:
Attachment 241489
Attachment 241490
BTW: I figure a two-projectile load helps satisfy that "need to shoot again when firing a pistol" that you mentioned.
Hopefully it produces a wider damage cavity of some kind.
Wider than what?Quote:
Originally Posted by 35remington
It's hard to see how two sharp-edged wadcutters crushing two separate full-caliber wound channels with the combined cross-sectional area of a .50 caliber and penetrating well beyond the FBI minimum standard isn't about all you can squeeze out of a .38 snubby. Or am I overlooking something?
Wider rather than narrower. I get the intent. Always have.
Do you mean wider like this?Quote:
Originally Posted by 35remington
Attachment 241523
Wider however you can produce it to effective depth with two projectiles. That is the topic I believe.
I am a bit leery of trying it in stubby autoloading or revolver cases.
I'm impressed by the penetration that you are getting, even with these light weights, and as slow as 625 fps. If I recall correctly, muzzle loading folk have noted that round balls penetrate further at lower velocities - that is, at short range they penetrate less than at long range, after they have slowed down. Gel tests with black powder pistols show that a short barrel Sheriff's model generating 750 fps will actually penetrate deeper than a long barreled Army at over 1,000 fps. Dead soft round balls do flatten somewhat, so maybe comparing them to hard cast wadcutters is "apples and oranges" - but it would be interesting to know the penetration of identical wadcutters at various velocities. Nice work, thanks for sharing.