What mini-sized guns have the highest power-to-weight ratio?

It's probably more like half the rifle muzzle energy. In which case the S&W Scandium .357 has a higher power-to-weight ratio. The 50BMG Pistol's uselessness aside.

I realize the original poster specified small guns, but we seem to now be talking about guns of all sizes,

The highest power-to-weight ratio of any repeating handgun made is the 5" half-lug Performance Center 500 I got S&W to make for me.

Using long-nose (and thus short-shank) bullets to increase the net powder capacity some 25% over rounds loaded to shorter OALs, and with the 5" gun's muzzle nut that allows the barrel/cylinder gap to be set at half the dimension of production guns, you can get over 2000 FPS with 400 grain slugs, over 1800 FPS with 450 grain bullets, and over 1700 with 510 grainers, at pressures within SAAMI spec.

These loads give 950 to over 1000 foot-pounds of energy per pound of gun weight. (The gun weighs 3 lbs. 9 ounces.)

There is an extensive article about these guns in the May 2008 Gun World.

This is what the gun can do. It is a joy to shoot with 400 grain long-nose bullets at more modest velocity, say 1450 FPS. The low pressure (from greater case capacity) and lack of blast (from no brake), combined with the greazt balance make for a great working revolver. Many customers who bought one are buying a second copy in the other finish.

For the history of this gun, go to http://www.john-ross.net/store.php and click on the link at the bottom of the page.

JR

JR

Don't know about the 50 cal stuff, but my Kel-Tec PF9 is tiny, reliable, light and available...multiple Gold Dot 9s should just about cover my needs.

The old O/U American Derringer in .44 Magnum...but you probably won't want to shoot it more than once.

Ask me how I know...

A S&W revolver in 357 (340PD) is pretty bad. I have no desire to use one. At some point the power/size ratio surpasses a practical level.

357-8,

The recoil is more than the standard gun, but the blast is so much less I find the overall effect to be much better. My buyers seem to agree.

JR

It's funny how the majority of answers are never the answer to the original question,kel-tec, pf9 or seacamp in 380, ruger has a new 380 also, but you may want the 9mm as the minimum, amt 45 backup, isn't the smallest, or the lightest, but it carries easily for a 45. None of these are the most accurate past 10 feet but you probablly know that. I didn't mention the Kahr 40, or 45, but I believe someone else did. If cost is a factor, stick with keltec, 2 years ago I never would have said that, but the gun quality is now more up to par. I picked up a PF9, and it is real small for a 9mm, they claim it's the smallest in the world, who knows.

For compact firepower I go with either a Makarov or an old-school Charter Arms Bulldog in 44 Special

Jorg said:

None.

Click to expand...

This is probably the closest to the mark , but some still give you a better chance than others.

I will say subcompact but still service cartridge pistols like the Kahr PM9 or PM45, or .357 Magnum snubnose revolvers.

When in doubt...shoot him in the face.

FWIW, myPF9 will easily shoot 2" groups all day long from an offhand standing position.

Kingjoey...I also have a CA .44 Pug...same level of accuracy with 2" groups the norm.

As Pigspitter said...shoot'em in the face, repeat as needed.

I'ld put my money on one of those insane .45-70 deringers..

If one were to be stupid enough to fire a full load, say Garrett Hammerhead, at 3200ft/lbs
in an 8 ounce package..


outch..

It's funny how the majority of answers are never the answer to the original question,kel-tec, pf9 or seacamp in 380, ruger has a new 380 also, but you may want the 9mm as the minimum, amt 45 backup, isn't the smallest, or the lightest, but it carries easily for a 45. None of these are the most accurate past 10 feet but you probablly know that.

Click to expand...

Actually, the accuracy for these little guns doesn't change much with distance until velocities start falling off a good bit, just like other guns. The accuracy at 10 feet is the same as 5 and as 25 or 75. A 1" group at 10 feet is the same accuracy as a 0.5" group at 5 feet or a 2" group at 20, or a 7.5" group at 75.

With that said, the little guns may be more difficult to shoot well at distance because their ergonomics are not conducive to good marksmanship, but that is a matter separate from accuracy.

Many rifle caliber arms with extremely short barrels (just a little longer than the cartridge) do not actualy have the tremendous energy you would think. Those rounds from the factory come with powders designed to make the most from a longer barrel, often with slow powders or progressive burns meant to keep them at high pressure for a longer period of time in the barrel.

What that means is that while still a big round in a really short barrel, a lot less of the energy created between the breech and the bullet, and more of it is turned into a large fireball and a lot of noise outside the gun.
That means they are often equal to some of the mid range handgun calibers, and not even in the realm of many of the big bore handgun cartridges.

There is a barrel length minimum for many rifle calibers, below which much of the powder does not get turned into energy because only some of it combusts before leaving the firearm.

Ruger Super Redhawk Alaskan in .454 casull...

Beats the .50 BMG "pistol" for weight-to-power ratio.

1700-1800x6 / 41 oz

1700ft/lb*6shots/2.5625lb = 3980 ft/lb per lb weight of unloaded revolver

also, it has a 2.5" barrel. Wiki lists 240gr standard pressure 454 casull as 1900+ ft/lb when shot from 7.5" barrel.

So...a clear winner in the efficiency department.

As for the practicality dept, why not just find a balance of all the important features instead of looking for raw numbers. Because you'll end up with something weird, as people have illustrated.

"Six for sure plus a probable broken wrist and nerve damage"

I'ld put my money on one of those insane .45-70 deringers..

Click to expand...

Many rifle caliber arms with extremely short barrels (just a little longer than the cartridge) do not actualy have the tremendous energy you would think. Those rounds from the factory come with powders designed to make the most from a longer barrel, often with slow powders or progressive burns meant to keep them at high pressure for a longer period of time in the barrel. The additional case capacity is also designed to allow them to generate additional energy for longer, a useless feature if max pressure is reached early on and the bullet then exits the barrel when there is still plenty of leftoever unnecessary powder burning afterwards
The the very dimensions of the round were not designed for such a platform, which means it will never even meet a fraction of its potential.

What that means is that while still a big round in a really short barrel, a lot less of the energy is created between the breech and the bullet, and more of it is turned into a large fireball and a lot of noise outside the gun.
That means they are often equal to some of the mid range handgun calibers, and not even in the realm of many of the big bore handgun cartridges.

There is a barrel length minimum for many rifle calibers, below which much of the powder does not get turned into energy because only some of it combusts before leaving the firearm. For some cartridges it is 6 inches, for some 8, for others 10 etc (they they continue to gain energy much longer than just the burn time, but that curve is less severe that the initial one.) You can vary it somewhat with different powders, but that can only work within the limitations of the cartridge.
So the difference between a 12 and 20 inch barrel for example is far less than between a 5-10 inch barrel with most rifle calibers. Those first inches are the most important.
You can't just replace it with much faster powders either, as most of the case capacity is wasted, and if you try to use most of that large case capacity with fast powders it would exceed pressure design and explode. So you in fact have a much larger cartridge than necessary for that level of performance out of that length barrel. A waste all around.
That is why an actual round designed from the start as a powerful handgun round can often have more energy in such size barrels than a rifle caliber with standard rifle ammo. A .500S&W for example is more powerful than most rifle calibers would be from a short handgun length barrel, especialy a carry length barrel.
Even relatively fast burning shotgun powders in a wide shell (read more surface area near primer and faster ignition) needs ~8 inches with many factory loads before it finishes burning.
So a round in a shorter barrel than necessary to burn the powder will result in less energy, less recoil, larger fireball and possibly muzzle blast, and will waste most of the ballistics of that round.


I repeat there is a big difference when people cite a difference of a couple hundred feet per second between inches of barrel not involved in the burn process of a round, and those critical inches at the start which can cut the energy into a small fraction of the rounds potential.
Those later inches are just how much longer the pressure generate is being applied to the rear of the bullet. The initial inches though are how high the pressure is able to get to begin with, not how long it is applied. If the round cannot even reach its designed pressure level, it is not even the same round, and you might as well just rename it something like .45 FCEW (Fireball Creating Energy Waster.) As your only options are to waste most of the cartridge capacity and use a faster powder for the same perfomance, or waste a ton of slow powder out the front in a large fireball.

So magnum handgun rounds tend to be more powerful from tiny firearms than even rifle rounds, especialy factory rounds, until you at least have the minimum barrel length necessary to contain the burn time and reach standard pressures. Otherwise you are just wasting powder for performance you could have achieved with lower quantities of faster powder, as loaded in pistol rounds.

The power of a cartridge is tied to its maximum pressure, its case capacity, and the width of the base of the bullet, with larger amounts of surface area putting that pressure to use quicker (why a low operating pressure shotgun still puts that low pressure to good use with a big heavy projectile.)

A short barrel limits the usefulness of case capacity as you will still reach maximum pressures before doing all that is possible with the space capacity. Meaning you might as well use a shorter round with hotter powder out of that length barrel.
The max pressure is the limiting factor on how much energy can be applied while it is in the barrel.
The bullet width is the limiting factor in how much surface that pressure is applied to in the time it is in the barrel. The bullet weight can be tailored to best meet that high pressure for the longest period of time without exceeding it.
The round's energy is limited by the weakest link in there.
Most rifle rounds are only vhastly more powerful than pistol rounds if they have time to burn sitting near thier maximum pressures while the bullet is speeding down the barrel. Thier high pressure levels and higher case capacity allow them to continue keep them at near maximum pressure for many more inches of travel than most a pistol rounds. Most pistol rounds release thier energy suddenly and only reach operating pressure for a fraction of the time a rifle round applies its energy to the bullet.
That means by the time thier bullets travel many inches they have been imparted with energy for a longer length of time as the cartridge continued to generate more pressure for several fold longer than a pistol, but they still have to travel those inches of burn to get there. Simply being a powerful rifle round does not make them powerful from any platform.

Personally, my trade-off in power/weight stops at the .357 2.5" K-frame. After years of various guns, I've settled on this as my personal optimum "power" carry package. The steel frame gives enough weight for good control and follow on shots (about as good as the 4" versions) with full power .357 loads, and while there are lots of good knock-down rounds, full power .357 cannot be faulted as a choice. I just do not enjoy shooting lighter and smaller guns with the .357, and I don't like packing anything larger.

You can really only get so powerful from a compact package. The two limiting factors if a short barrel and short burn time is a given is maximum pressure and bullet diameter.
Well since bullet diameter is legaly restricted to a maximum of .50 the only variable left to work with is max pressure. If we take a look at Saami pressures, the highest pressure manufacturers even in rifle calibers seem to feel comfortable with is around 65,000, (though some have gone to around 67k in crusher tests.)

So that means the highest pressures most feel comfortable reaching using available metal alloys is 65,000 giving at least a little room for safety.
That has nothing to do with max energy, but with what metal can withstand based on formula and crushers made to various standards including SAAMI. Even the BMG operates at well below that, around 54,000.
(Meaning a more powerful rifle operating near 65k can be made as well that would outclass the BMG in the .50 caliber range for power. Though with such a high cartridge volume that is just asking for trouble as if any of the burn timing does not go as perfectly designed pressures could spike creating a catastrophic failure without some room for error. A feasible private gun, but commericaly that is a liability nightmare. A single batch of slightly off ammo would have people holding detonating bombs.)

So if limited to .50 caliber, and limited to 65k pressure, there is a theoretical maximum that cannot be exceeded unless allowed to go above .50 diameter or metalurgy capabilities change and allow for higher safe pressures.

Even the .500 Smith & Wesson Magnum only operates at around 50k. So there is still room to make a more powerful cartridge. Essentialy a .500 designed for 10-15k more pressure, or 60,000-65,000.
That will be about the legal theoretical max (whether or not your wrist's physical max is met prior.)
There will then be a minimum amount of metal that could contain 65k pressures. The .454 Cassull manages it though and has been chambered in the Ruger Alaskan, of course it has a bit of dead weight for the OP's question.

Something similar with the bare minimum handle trimmed of extra parts, maybe a hook on the front to compensate for lowest weight tiny handle, and chambered in a yet to be commercialy produced 65k pressure .50 caliber handgun cartridge. Then you would have the highest power to weight ratio handgun legaly allowed.

Of course the round needs to be invented first.

In my opinion:

.357 Magnum Snubbie: S&W 340 M&P
Kahr PM9, 9mm, 7 shots, can handle +P ammo (yea, my carry gun )

"Even the .500 Smith & Wesson Magnum only operates at around 50k."

Er...no. SAAMI spec max is 60k. Loading to this level at an OAL of 2.320" to make use of the whole cylinder gives truly impressive ballistics.

JR

Er...no. SAAMI spec max is 60k. Loading to this level at an OAL of 2.320" to make use of the whole cylinder gives truly impressive ballistics.

Click to expand...

You are correct, most factory loads are just in the 50k range.

So I guess there really is not much room left for legal improvement, just a few k of pressure.
Unless someone makes a slightly oversized round that ATF approves because the rifling blocks the plug.

Now you just need a smoothbore .500S&W to get even higher velocities and less resistance from the rifling, of course legaly you can't omit rifling either.

So working within the law the .500 S&W has hit a limit.

Maybe someone can get a destructive device exemption for a big game handgun cartridge.

Maybe I am just a wimp, but I would rather have a heavy gun in such a cartridge.

Mini, no but pretty small (and a bit heavy) is the Para Ordnance Carry LDA in .45 ACP



Here's a link to it's specs. Easy to shoot and min was very accurate. Never should have sold it.