Idea for an improved .380 projectile

[VelveteenMole]

I was thinking about the dilemma created by the .380 ACP cartridge. Hollowpoints that manage to expand underpenetrate, and bullets which do not expand tend to minimize permanent wound diameter due to the the tendency to slip through elastic tissue. Even flat nosed FMJs don't really crush a clean plug of tissue out ahead of them and I would think produce a wound functionally no different than round nosed FMJs.

Here's my thought. What if you took a copper solid similar to a DPX, eliminated any weakening serrations in the meplate, and then drilled 4 to 6 sluice holes through the walls of the bullet so they ventilated the base of the hollowpoint cavity. A small cone or even angular, star shaped protrusion could be milled or stamped in the bottom of the cavity, cleaving the tissue entering the cavity, directing it out through the sluice holes. Alternatively the bottom of the cavity could terminate below the holes like a sump in order to accept some compressed clothing while allowing tissue to exit above it.

The purpose of this design would be to cut a true, permanent wound channel in tissue through the full penetration depth by preventing compressed tissue from immediately clogging the cavity causing the bullet to simply slip through the elastic tissue like a FMJ. If the sluice holes could drain as fast as the cavity fills, a fresh "cutting edge" of the meplat would always be exposed to tissue. While this would not increase the diameter of the bullet, it would maximize the vascular damage and blood loss within the meplat's diameter while hopefully maintaining the superior penetration afforded by the sectional density of an unexpanded bullet.

I do realize 9mm is preferable, but the reality is many people still opt for the convenience of a true pocket pistol, at least under certain circumstances. This design could be a significant improvement over current projectile options.

I'd be interested in seeing if anyone here could manufacture a few of these and test them in gel. Hell, at the very least they might whistle when you shoot them

Any takers?

[wrinkles]

Don't know if you ever saw these. Not exactly like the bullet you're describing.

The Action Safety Bullet

They decided on an all-copper bullet with a huge hollow point that led down to a hole that ran clear through to the base of the bullet. It was essentially tubular, but the front cavity was filled with a plastic plug shaped a bit like an opened umbrella.

[Entropy]

The .380acp does a decent job of what it was designed to do.........fire a .355" round nosed bullet at moderate velocities to penetrate through the torso of a human being using a cheaply made pistol.

However, it was designed with so many limitations on versatility that it is a dead end cartridge today. The bullet itself is too short, resulting in low sectional density, and low momentum. When you try to convert it to a JHP, that low sectional density and momentum becomes blindingly obvious as the .380 in JHP has very shallow penetration......especially through barriers. Due to the case and charge limitations, you can't stick a longer bullet on there..........and if you were able to, the velocity would be so low that it would drastically diminish its performance. The best .380acp load I've found is the Remington 102gr GS JHP. It has enough rounding on the nose to help it feed reliably in direct blowback pistols with a partitioned feed ramp, and the bullet is seated deep enough to allow for a larger crimping area and reduced chance of a setback. However, even it shows mediocre performance with only 7-8" of penetration in bare gel.

A better mouse/pocket gun caliber would be something that can mimick the versatily of the 9mm/.40/.45acp, only in a smaller caliber. In order to be as short as the .380acp and have that versatility, it would probably need to be about a .30-.32 caliber with a bullet sectional density on par with the 9mm 147gr.

[VelveteenMole]

The .380acp does a decent job of what it was designed to do.........fire a .355" round nosed bullet at moderate velocities to penetrate through the torso of a human being using a cheaply made pistol.

However, it was designed with so many limitations on versatility that it is a dead end cartridge today. The bullet itself is too short, resulting in low sectional density, and low momentum. When you try to convert it to a JHP, that low sectional density and momentum becomes blindingly obvious as the .380 in JHP has very shallow penetration......especially through barriers. Due to the case and charge limitations, you can't stick a longer bullet on there..........and if you were able to, the velocity would be so low that it would drastically diminish its performance. The best .380acp load I've found is the Remington 102gr GS JHP. It has enough rounding on the nose to help it feed reliably in direct blowback pistols with a partitioned feed ramp, and the bullet is seated deep enough to allow for a larger crimping area and reduced chance of a setback. However, even it shows mediocre performance with only 7-8" of penetration in bare gel.

A better mouse/pocket gun caliber would be something that can mimick the versatily of the 9mm/.40/.45acp, only in a smaller caliber. In order to be as short as the .380acp and have that versatility, it would probably need to be about a .30-.32 caliber with a bullet sectional density on par with the 9mm 147gr.

All the bare and clothed gel tests I've seen in the 90-95gr range show ideal penetration (16-18") with FMJs. If the cavity was shallow and perhaps even backed by a lead cored base, I don't see why at least 90gr couldn't be reached and such a non-expanding, ventilated "coring" structure wouldn't be likely to reach 12" of penetration. Failed Hydra-shoks seem to consistently reach 12" in gel after Tshirts, but they're not going to core out the entire depth because they'll immediately fill with compressed tissue, effectively becoming irregular wadcutters due to their typically minimal/caliber-size nose expansion.

I'm not going to worry about barriers here, there's always atypical situations to point to that justify the next step up in weaponry. I'm simply trying find the sweet spot of what can be done within the performance envelope of the admittedly anemic .380 simply because it lies just on the other side of a significant jump in platform size while retaining the 9mm's diameter. This size jump makes .380 inevitably popular as a close defensive weapon. Why not maximize its terminal ballistics beyond what's available by both reaching FBI depth and minimizing the FMJ's piercing effect? I think a bullet along these lines might be capable of achieving those goals.

ETA: The main goal here that I'm looking to balance with penetration is creating a wound channel that for its entire length doesn't completely close back on itself in a compressed fashion.

[VelveteenMole]

Don't know if you ever saw these. Not exactly like the bullet you're describing.

The Action Safety Bullet

Never seen them. Found a pic. I'm baffled as to how they maintain pressure in the barrel if the nose guide is all that plugs the hole and from the front at that. Seems they were designed to blow out tires, but supposedly worked well in tissue for the same reasons I think my idea would. Though I did see a picture that seemed to be one that mushroomed, likely an effect of the single quite narrow hole to the base not allowing tissue to flow out anywhere near as fast as it entered. I would be trying to reach a near 1:1 flow rate and minimize resistance. Perhaps it could be tuned to encourage mere caliber sized expansion at a controlled rate, depending on the resulting penetration of course as a parameter.

[LDM]

Entropy's thoughts on a .32 round sounds a bit like the .32 North American Arms round.
Not sure a bullet has been optimized for this round, though.

post script- Corbon has an all copper DPX load in .32 acp. Is this a Barnes bullet? If so, that bullet loaded as a .32 NAA might be kinda interesting.

[VelveteenMole]

Perhaps the most efficient shape would be with a cavity of conical shape of close to 45* with sluice holes drilled in at an angle to exit the walls just at the start of the ogive. This would minimize velocity variance caused by inconsistent rifling engagement.

[Entropy]

So basically you're talking about a wadcutter that exhausts the tissue in its path. I think that a bullet traveling at 1000fps would be too fast to allow all the solid tissue material to squeeze its way through small drilled holes. Energy takes the path of least resistance, and forcing fluids/solids through small holes in a 360 degree exhaust arc would not work and would either just plug up the front cavity or deform the nose. Munitions engineer Kent Taylor with Winchester tried something similar with the .357mag in the early 1960s, but it never worked as planned on paper and the research was scrapped in favor of mushrooming hollow points.

Even if you could get such a bullet design to work, I think you'd run into the law of diminishing returns. It would be complex to manufacture, require bimetal construction to have a soft shell(barrel life) and a hardened core to maintain shape, and be very expensive. I think you'd be much better off spending your time and money buying cases of .380 FMJ and train like your life depended on it.

[VelveteenMole]

So basically you're talking about a wadcutter that exhausts the tissue in its path. I think that a bullet traveling at 1000fps would be too fast to allow all the solid tissue material to squeeze its way through small drilled holes. Energy takes the path of least resistance, and forcing fluids/solids through small holes in a 360 degree exhaust arc would not work and would either just plug up the front cavity or deform the nose. Munitions engineer Kent Taylor with Winchester tried something similar with the .357mag in the early 1960s, but it never worked as planned on paper and the research was scrapped in favor of mushrooming hollow points.

Even if you could get such a bullet design to work, I think you'd run into the law of diminishing returns. It would be complex to manufacture, require bimetal construction to have a soft shell(barrel life) and a hardened core to maintain shape, and be very expensive. I think you'd be much better off spending your time and money buying cases of .380 FMJ and train like your life depended on it.

Fair enough. Good info.

[200RNL]

Judging from the maximum penetration numbers of 95gr FMJ bullets in this caliber, I would say that a non expanding FMJ wadcutter bullet would be the best performer in this caliber. But, as we all know, a full wadcutter bullet will not feed well in a semiauto pistol.

Perhaps a bullet patterned after the short nosed and sharp edged 185gr .45ACP FMJ wadcutter might work.