Among 45 ACP factory ammunition, which have the highest penetration on hard targets, such as wood, sheet metal, and other. I don't refer to ballistic gel or animal hunting performance. Just harder target penetration.

Would I be accurate in anticipating factory 10 mm ammunition achieves somewhat superior penetration on the same materials? I am not aware of factory 10 mm ammunition having bullets designed for such penetration while I expect 45 ACP to have a much wider spectrum of bullets possible,

Short answer, 10mm will penetrate target materials you specified far better than any .45 ACP factory load. This is due to the far higher bullet energy levels of the 10mm because of velocities of nearly any 10mm load being 150% of any .45 ACP ammunition. 10mm is available in full metal jacket truncated cone configuration just like the .45 ACP.

We are talking about relatively thin mild steel plate up to ca. 1/8". If you get much thicker than 1/8" virtually no handgun cartridge will penetrate it except, possibly, .460 and .500 S&W, .475 Linebaugh, and .454 Casull or similar cartridges. This is the only one of your materials that can be considered as "hard". Neither wood nor sheet metal such as auto body steel can be considered to be a hard target material.

I remember taking a 1911 to a trash dump, loaded with 185 gr factory loads. Besides killing tin cans, we had an old junked car to shoot at. It was upside down, mostly intact. We shot that with my 45, a 357 Highway Patrolman and a model 29 44 mag.
I was enlightened about "45 ACP doesn't penetrate" when I shot from the side into the driver's door. It exited out the other side through the passenger door trim and sheet metal.
A shot from the 44 mag went through the rear bumper, through the trunk lid, through rear and front seats, the dash, and exited through the hood. Contrary to Dick Tracy and other radio cop stories, we could not get the 357 to crack the engine block.

Never really tried any "hard target barrier testing" with a .45 acp, but I did work up a load to carry for deep penetration while camping and traveling in the black bear / moose woods. It is a hard cast WFN type bullet that casts out to about 240 grains. I push them with a warm load at about 950 fps. I have gotten thru and thru penetration on a couple whitetails I have shot with this load, and figure it should penetrate about any barrier a .45 acp is going to be able to.

A good source for a non reloader might be one of the small specialty manufacturers like Buffalo Bore, etc.

I am thinking because of higher velocity, and better bullet sectional density, a 10mm with a similar bullet would penetrate better. I don't know typical jacketed FMJRN's bullets hold together better than a properly hard cast and water hardened lead bullet. Most FMJ handgun bullets are of thin jacket and soft lead cores. They can deform when hitting something hard, limiting penetration.

Larry

The scenario you posit requires two things: bullet integrity and velocity. Any given bullet type can be found in either named caliber Once you've picked an appropriate bullet, velocity decides penetration.

Once upon a time bullet performance was judged in penetration boxes. One inch pine boards spaced one inch apart. Good luck finding one inch pine boards these days. Although if you're doing comparative testing whatever you get from Home Depot or Lowes will work.

On YouTube are videos of a man shooting cast iron and steel skillets using various handgun cartridges. Good insight. The 9mm's just blew through. 22's made little dents as did others like 38's. The 45 ACP never penetrated any of the skillets, leaving only dents. Results were in line with US military tests after the war. Shooting a GI and German helmets with 45's and 9mm's, the 45's just made a large dent, 9mm's penetrated completely one side and either dented or passed though the opposite side. Higher velocities and smaller frontal area were the key. Dangerous game cartridge from the dark continent proved like results. The mighty and massive 577 and 600 Nitro cartridges were not highly thought of as their penetration was far less the smaller, faster 500 Nitro.

When we were little kids, we used to run on top of the cars from front to back and not put a dent in them. Try that now. Paul Harrell demonstrated the the only thing in a car that can stop a bullet is the engine, and I think most wheels but I wouldn't guarantee it, and besides, I'm bigger than the wheel.

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That 7.62x25 Tokarev round is said to be quite a penetrator. High speed and small frontal area seem to be a common theme when it comes to burrowing through stuff.

I once shot an already destroyed large gas canister with a soft-nosed Remington .303 British round. I expected the round to pancake on the outside, because of the exposed lead, but it punched straight through leaving a ring of the jacket around the circumference of the hole. Granted this was at about 15 yards or so, but I was still surprised.

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Solid copper bullets and monolithic bullets are said to be excellent penetrators of barriers.

Companies such as Underwood Ammo and others manufacture and sell both.

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I bought a 6 in. Python in 1965. A friend had a Desota transmisson outside his shop and told me to shoot it and see if it would put a hole in it. I shot it with a factory load and the bullet just made a grey mark. I shot it with a reloaded 158 gr. hard cast and it knocked a hole. Factory loads wouldn't penetrate car wheels but the hard cast reloads would. One of my mentors accidently shot the engine of his Ford tractor with a hard cast and it knocked a hole. The lead in a factory load is to soft to penetrate metal. My mentor and I determined that a hard cast lead bullet would penetrate metal as good as a ,357 metal piercing bullet. Larry

I don't think anyone had in mind extreme penetration of hard targets when the 45 was designed. It was purely anti-personnel with reliable function in an auto loader. Thus making a big hole without extreme velocity. Rifles were the primary weapon and by that time they had plenty of penetration where needed.

.45 auto is not the caliber for hard target penetration. The .40 and .357 Sig are much better. The 10mm superior.

Looking for penatrating factory ammo for the 10mm call Underwood. I carry a 10mm when hiking out west loaded with Underwood's ammo with hard cast bullets. I hope I never have to use it.

I've never heard much about .45 ACP being a good at hard barrier penetration.

I've heard a lot of praise for the hard barrier penetration of .357 SIG, .40 S&W, and 10mm Auto, seen it demonstrated as well, but never .45 ACP, not even in +P loadings.

I presume that the relatively low velocity, wider bullet diameter, and sectional density of .45 ACP just doesn't lend itself well to hard barrier penetration.
Perhaps that could be overcome with higher velocities out of turbocharged .45 ACP loads like .45 Super or .450 SMC, but those are honestly labeled as separate cartridges for a reason because they're in the same energy class as 10mm Auto, so they don't really count, nor can you shoot them out of any standard .45 ACP firearm (save for a USP45) without modifications to handle the higher pressures.

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"Hard Target" sounds like an Internet-era term even though it's meaning is clear, but what about the old Remington Hi-Way Master .45 ACP load from years ago? That was a 173 grain pointed jacketed bullet loaded to around 1140 fps. Wouldn't that do about anything from a penetration perspective that more modern cartridges would do? It certainly would seem so and it's pretty close to 10mm Magnum ballistics.

There was also a Peters loading .45 ACP loading that was the same or similar and Winchester Winchester loaded a 230 grain conical jacketed bullet to well over 900 fps during the same era. There may have been others.

Hard cast lead bullets are a good way to ruin metal targets. Buffalo Bore loads them for revolvers, but you can roll your own in any caliber. I've had no leading with Oregon Trail (silver-cast) bullets in carbines up to 1900 fps.

Not to forget that the US Army cavalry's requirement that it was capable of putting a horse down.