.38 double wadcutter load

[the Schwartz]

Thanks for the reply.

But I have to apologize for not being clear (no pun intended) in asking my question. No, I was asking about validated 10% ordinance gel. No Clear Ballistic product involved.

Ooooooooh, boy, just wait until you get my bill!

For example, the mTHOR model predicts a .36 caliber 110 grain WC at 650 ft/s will penetrate about 13" of validated 10% ordinance gel. So, can you think of any reason that 13" couldn't be considered the absolute minimum predicted penetration for two .36 caliber 110 grain WCs fired simultaneously at 650 ft/s into the same validated 10% ordinance gel?

So long as one can guarantee (which is unlikely) that both of the projectiles striking the target simultaneously behave independently of one another, I should think so. Of course, this assumes enough radial dispersion between both of the projectiles' points of impact so that no whole or partial intersection of the temporary/permanent wound cavities occurs and that no non-uniform projectile expansion or deformation* occurs during the penetration event.

*esp. that caused by the trailing projectile's nose being smashed into the rear of the leading projectile in a duplex load.

[the Schwartz]

I didn't want to see your contribution buried by all of the other material here, so I thought that it might be nice to comment on it here—

I'm happy to contribute.

And I'm glad you brought up the Duplex load. As a ballistics nerd, I absolutely love oddball, niche ammo. AP projectiles, duplex, sabots, flechettes - all are fascinating.

Here's some more info that may help on your quest:

Colts Salvo Squeezbore project:
http://gigconceptsinc.com/Colt-SSB.html





DoubleTap's line of 'Equalizer' Duplex loads:
http://www.doubletapammo.net/index.p...y&path=126_131

https://www.shootingillustrated.com/...mmo-equalizer/



And velocity testing of .38 Special Duplex ammo:
https://www.youtube.com/watch?v=TfCiKmYtKg4


The US Army is also pursuing Duplex ammo for their .50 BMG:
https://ndiastorage.blob.core.usgovc...iSmallArms.pdf

I'd never heard of this design until you posted it here.

The idea of three 33-grain truncated cone .30-caliber sub-projectiles at 1,226 fps to 1,390 fps is interesting, but the rate of radial dispersion with an extreme spread of 6.3 inches at just 50 feet and 42 inches at 47 yards rules it out for SD use for obvious reasons.

I am surprised that the rounds do not drive pressures through the roof as they are effectively 'extruded' as they pass through the SSB muzzle 'adapter' assembly.

Thanks for posting the information! Very cool.

ETA: I think that it also worth noting that according to all three bullet penetration models, at even at their highest velocity (1,390 fps), these 33-grain .30-caliber sub-projectiles struggle to penetrate much farther than 12 inches.

For a single .30-caliber "sub-projectile":
Q-model: PEN = 12.530 inches; Total Wound Mass = 9.997 grams
mTHOR model: PEN = 12.670 inches; Total Wound Mass = 10.109 grams
MacPherson model: PEN = 12.392 inches; Total Wound Mass = 9.853 grams

[JAD]

.

At least around here, .380 ACP is considered the floor for a self defense semi because it will reliably break bone.

I think 9x19 is the floor. I do not define “around here,” but I’m fairly sure that @DocGKR is where I got that impression, and to me he does lead the consensus on the topic.

[spyderco monkey]

I didn't want to see your contribution buried by all of the other material here, so I thought that it might be nice to comment on it here—



I'd never heard of this design until you posted it here.

The idea of three 33-grain truncated cone .30-caliber sub-projectiles at 1,226 fps to 1,390 fps is interesting, but the rate of radial dispersion with an extreme spread of 6.3 inches at just 50 feet and 42 inches at 47 yards rules it out for SD use for obvious reasons.

I am surprised that the rounds do not drive pressures through the roof as they are effectively 'extruded' as they pass through the SSB muzzle 'adapter' assembly.

Thanks for posting the information! Very cool.

ETA: I think that it also worth noting that according to all three bullet penetration models, at even at their highest velocity (1,390 fps), these 33-grain .30-caliber sub-projectiles struggle to penetrate much farther than 12 inches.

For a single .30-caliber "sub-projectile":
Q-model: PEN = 12.530 inches; Total Wound Mass = 9.997 grams
mTHOR model: PEN = 12.670 inches; Total Wound Mass = 10.109 grams
MacPherson model: PEN = 12.392 inches; Total Wound Mass = 9.853 grams

Yeah it was a cool project, and exactly the sort of odd ball, out of the box ammo that I love researching.

Whats worth noting in terms of dispersion is that for the project, that was considered a feature, and not a bug.

For the military, Duplex / SALVO / ACR, a standardized shot dispersion was the goal. The idea was that it would turn a near miss into a hit, greatly increasing the hit probability in combat, especially against pop up and moving adversaries:

This was the ad copy for the HK G11's 3rd 'hyperburst' showing the idea:


And here was the shot dispersion for the old 7.62 Duplex load:


As an aside, thats always something that has amused me about the Federal Flite Control shotgun load. The military spent hundreds of millions of dollars and decades of research to give rifles some of the hit probability of shotuns, and here we are trying to give shotguns more rifle like dispersion.

[willie]

Duplex loads have been in the literature for many decades. Few have given them serious consideration. The Army experimented with a duplex 7.62 NATO round which was never adopted.

[WDR]

I have a vague understanding of all the math you fellers are hashing out here and arguing or conversing about, but it seems pretty obvious to me that the proof is literally in the pudding, er, jello, ah, I mean calibrated 10% ordinance gelatin. You can math this stuff to death, but unless someone is willing to invest time and money into proper testing, its mostly just theoretical. Theories and reality are often far different from each other.

It seems to me that duplex/triplex loads are rather unpredictable, both in shot placement at extended ranges, and in their terminal effects on target. If you are arguing that such loads are more effective at short range, while dismissing the long range problems, I personally feel like you are placing great faith in chance dealing you a short range problem when the elephant shows up.

People have been searching for a magic bullet for some time now, and generally have not found what they were looking for.

[SiriusBlunder]

I think 9x19 is the floor. I do not define “around here,” but I’m fairly sure that @DocGKR is where I got that impression, and to me he does lead the consensus on the topic.

Thanks for clarifying.

I definitely don't want to give the impression I'm speaking for @DocGKR and know there's no .380 ACP loadings recommended in his stickies. I don't want a new reader to the thread or site to get that idea.

I get the impression that it's accepted around here (the whole forum) that a .380 ACP will reliably break bone and a G42 is now acceptable as a take out the trash option. I was trying to give the OP something to compare all his proposed ~100 gr/~600 FPS loads to.

My take "out the trash" option is my 9x19 EDC so I have no problem having that statement removed/modified.

My apologies to everyone for over stepping my bounds and speaking for "around here".

[BehindBlueI's]

I get the impression that it's accepted around here (the whole forum) that a .380 ACP will reliably break bone and a G42 is now acceptable as a take out the trash option. I was trying to give the OP something to compare all his proposed ~100 gr/~600 FPS loads to.

My take "out the trash" option is my 9x19 EDC so I have no problem having that statement removed/modified.

My apologies to everyone for over stepping my bounds and speaking for "around here".

FWIW, I don't think you're 'overstepping' or overstating. I think it's pretty well accepted that the duty cartridges are best but that the .380 is the absolute floor absent some medical condition, etc. that forces a smaller cartridge. The reason for it is the breaking of bone, which the .22, .25, etc. won't reliably do.

Now back to your regularly scheduled multi-projectile conversation.

[Wayne Dobbs]

It's likely a small thing to many of you, but it's NOT "ordinance" gel, but is "ordnance" gel. One is a law or legal rule, while the second has to do with munitions. It's the same maddening thing as messing up "their/there/they're" and "to/too/two."

[pettypace]

It's likely a small thing to many of you, but it's NOT "ordinance" gel, but is "ordnance" gel. One is a law or legal rule, while the second has to do with munitions. It's the same maddening thing as messing up "their/there/they're" and "to/too/two."

Good point. And I can see that I've been a regular offender. Sorry about that.

Is "BG" an accepted abbreviation for "validated 10% ordnance gelatin?"