Stupid gun question

[GM1967]

Double the weight of a bullet and you double it's energy.
Double the velocity of a bullet and you quadruple the energy.

This is true, but doesn't tell the whole story about energy, or how it is weighted in favor of velocity. The formula for kinetic energy is:

1/2 mv2

Or one-half of the mass times the velocity squared

This means, triple the velocity, and you get 9 times the energy

Triple the mass, you get one and a half times the energy.....not so good


As far as bullet effectiveness, it doesn't tell the whole story by far.....but it is the quickest metric to look at. Obviously, we need a better metric....but so far, we don't really have one, as far as I know

 

[JohnKSa]

Triple the mass, you get one and a half times the energy.....not so good

Since kinetic energy and mass are linearly proportional, if you triple the mass the energy will also be tripled.

Ke= (1/2) x M x V²

Triple the mass --replace M with (3 x M)

New Ke= (1/2) x (3 x M) x V²

By the commutative property of multiplication that's the same thing as:

3 x [ (1/2) x M x V² ]

...which is clearly triple the original quantity. Some sample calculations will bear that out.

Obviously, we need a better metric....but so far, we don't really have one, as far as I know...

It is my firm belief that there will never be a single number which can fulfill the requirement of being a complete metric of terminal performance.

 

[Mike Irwin]

There's a lot of confusion about when the .38 Special was actually introduced to the shooting public.

It was in development for at least a year or more before it was actually rolled out; some authorities say development started in 1898-99 or so.

It seems that it was finally introduced to the shooting public in 1901 or 1902.

 

[salvadore]

So my use of Skeeter and Elmer loads in 38 cases in my .357s makes me wise beyond my years, right?

 

[P71pilot]

I am no reloader (yet) but it is my understanding that .357mag was released in 1935, and 10mm in about 1990. I am sure that 10mm being designed almost 60 years later, has a stronger case design and is probably rated for a higher pressure (maybe not). I know the 10mm originally spec'd a 200gr fmj bullet at 1200fps from a 4.5+/- inch barrel. But you can also load 200gr (or heavier, up to about 220grs) bullet in the.357 and push it about the same speed out of the same barrel length. Basically they can push the same weights at about the same speeds, BUT since the .357 is a smaller diameter and has a smaller cross section, a .357mag of equal weight bullet (to a 10mm bullet) will penetrate deeper. This is only useful for big dangerous game however. Now the 10mm has an advantage of being an automatic pistol round and it is much shorter, and it is a slightly larger diameter. So with the 10mm you can carry much more shots, in a rapid fire capable automatic handgun, with less felt recoil, and since the cartridge is shorter you can fit it in the handle of a lot of standard automatics like 1911s, sig 220s, large frame glocks etc...

I like the 10mm better. Dream gun is a Dan Wesson or similar 10mm 1911

 

[Hal]

BUT since the .357 is a smaller diameter and has a smaller cross section, a .357mag of equal weight bullet (to a 10mm bullet) will penetrate deeper. This is only useful for big dangerous game however

Sort of...
The .357 can have a higher sectional density, but, with a hollowpoint bullet, that's not always the case.

 

[feets]

One factor that is often not discussed is barrel length which is important when comparing 357 to 10mm. Almost all of the data you see published for magnum revolver rounds is taken with 7-8" test barrels. Most of the data for semi-auto rounds is taken with 4-5" test barrels.

If you are actually shooting 357 magnum from a 7-8" barrel it will be noticeably more powerful than best 10mm loads. From more common 4" barrels 357 mag will be noticeably less powerful than the best 10mm loads.

Kinda going off on a tangent here but...

I've got a S&W 25-2 and a Kimber Custom II. Running a variety of hand loads and factory fodder across the chrony have shown some loads to favor the 6-1/2" barrel and accompanying cylinder gap of the revolver while others were faster out of the 5" semi with it's energy-sapping blow back design.

Of course, I don't have to worry about those kinds of issues with my 10mm. It's a custom built 6" barrel on a Contender. I get all the scoot the round offers.