why isn't ammo designed for specific barrel lengths?

[tostada]

I know most ammo basically is designed for different barrel lengths, but manufacturers often don't tell you what that length is, and they don't really make similar ammo designed for different guns.

For example, is there any .22 ammo that's actually designed for a pistol? Stingers are supposed to be 1640 FPS, but that's out of a rifle. It'd be nice to know something was going to burn all its powder in a 5.5" barrel if that's what I was going to be putting it in. And it'd be nice not to have to look around for chrono results to see what ammo would be suitable for a certain gun.

How many of us are using the same ammo in a 9mm carbine vs. a 9mm competition gun vs. a 9mm service pistol vs. a 9mm sub-compact carry piece?

A lot of people don't seem to realize that when they stick their super nice expensive defensive ammo in a snubby the performance might just be terrible. That .357 J-frame might be needlessly shooting fire several feet out of the barrel.

Isn't the best ammo for a gun going to be made specifically for that barrel length? You get the maximum velocity for the barrel, and you're not wasting powder long after the bullet has left.

Maybe I just don't know what I'm talking about, though!

 

[4thPointOfContact]

Considering that a 9mm bullet traveling at 1,000 feet per second travels at 12,000 inches per second. Now think of the precision needed to have a powder that burned in a 3 inch compact barrel compared to a 5 inch full size.
That's Not a lot of time, is it?
For pistol to carbine comparisons, it's a little better, but not a whole order of magnitude, I think.



Heck I could be talking out my butt, but I'm just guessing.

 

[R.W.Dale]

For example, is there any .22 ammo that's actually designed for a pistol? Stingers are supposed to be 1640 FPS, but that's out of a rifle. It'd be nice to know something was going to burn all its powder in a 5.5" barrel if that's what I was going to be putting it in. And it'd be nice not to have to look around for chrono results to see what ammo would be suitable for a certain gun.

Because suitable propellants for a given cartridge have almost NOTHING do do with bbl length. Case capacity, bore case ratio and pressure rating are the factors for determining a suitable powder. The bullet going down the bbl is literally after the fact.Remember it's high pressure gas that drives bullets not burning opposite action reaction thrust like a rocket

Oh sure some ammunition for shorter bbl's may use some flash suppressants. But the burn rate is still dictated by the case not the barrel. A prie example is I have a 22' rifle and a 10" revolver chambered for 30-30winchester in the handgun the propellants that yield the highest velocities are the same top performers in the rifle

 

[rcmodel]

It really doesn't matter that much in .22RF.

They make "short-barrel" loads in center-fire handgun calibers already.

Other handgun loads are pretty much self-regulating by the power level they are loaded for. IE: .38 Special, .380 ACP, etc. is loaded with very fast powder. Magnums are loaded with slower powder.

In center-fire rifles, the powder that gives the highest velocity in a long barrel will almost always also give the highest velocity in a short barrel.

The only one I can think of that might really benefit from a "handgun" load is the .22 WMR. I do wish they had one for that.

rc

 

[JR47]

In handguns, there is some value to considering the burn times vs. the barrel length. Shorter barreled guns would benefit from a faster powder, as it would allow more acceleration in the available burn time. However, that same ammo, used in a longer barrel could raise pressures beyond the SAAMI specs, or affect the time/pressure curves that the pistol is mechanically designed for.

There's also the matter of logistics. Manufacturing ammunition in various calibers, for barrel length specific loads, is going to drive the prices up considerably, along with liability protection costs.

 

[moooose102]

are you serious? do you know how many boxes of ammo your local gun shop would have to carry to keep everyone happy? it would probably bankrupt him sitting on 30 times more ammo than he has now. if you want to get that specific, you NEED to handload!

 

[rickomatic]

Speer "Short Barrel Ammo"

As a matter of fact, the DO make barrel length specific ammo. Speer has their Gold Dot ammo out which is specifically manufactured to perform at optimum levels in short barrel revolvers.

 

[Jim K]

As noted by rickomatic, some ammo is designed specifically for short barrels and there is .22 ammunition intended for pistols.

But the idea of a powder that will burn fully within the barrel isn't feasible. The usual idea is that the powder will be consumed just as the bullet reaches its maximum velocity and that will be at the muzzle. But that is not quite the way it works. The bullet doesn't stop or slow down just because the powder is burned; the propellant gases continue to expand from heat and continue to put pressure on the bullet even though the powder has completely burned.

If the pressure stopped when the powder is burned, a .22 rifle with an 20" barrel would be silent, or bullets would never exit the barrel, since the powder is burned in about 16".

Jim

 

[ArmedBear]

I thought Cor-Bon's .38Sp+P defensive rounds are designed for snubbies. That's why I bought 'em.

It makes sense, since .38+P is a snubbie round, most of the time. In a full-size gun, .357 would be the round of choice, and for plinking in any of the .38/.357 guns, regular .38, not +P.

 

[bluetopper]

That's why in the Lyman manual it lists data for rifle cartridges to be shot in the Thompson Contender such as 22 Hornet, 223, 22-250, 243, 270, etc,.......

 

[mio]

mag safe has a 9mm round that is designed for a 2" barrel. supposed to push 2k feet per second but its way out of my price range so ive never shot any of it.