.22 Federal Bulk 525 Label

[bigdawgbeav]

Came across something interesting today. I just got in 4 boxes of Federal Bulk 525 pack from an online deal (http://eastcoastgunsales.com/product.php?ID=105815 - 4 boxes, shipping and tax = $72.91 or 3.4c/round). As I was reading the box, something I never really did, I found some numbers that just didn't jive. So I did the math and here's what I found.

On the box it said that a round is "lethal to 1.5 miles". I had to laugh at that a bit. Bullet drop was also listed at 5.6 inches for 100 yards.

1.5 miles = 2640 yards
2640 yards/100 yards = 26.4
26.4*5.6 inches = 147.84 inches
@ 1.5 miles the bullet drops 12.32ft

Yes i can understand firing at an angle and that kind of BS, but something else caught my eye:

Muzzle velocity @ the barrel is 1260 ft/sec. That drops to 1000 ft/sec. after 100 yards. If we use 260 as a constant (which it most likely isn't) we have the following figures:

1260 - 0 yards
1000 - 100 yards
740 - 200 yards
480 - 300 yards
220 - 400 yards
0 - 500 yards(approx.)

So before the bullet reaches 500 yards, it's done.

I understand that they have to print these kind of warnings, but I think that 1.5 miles is being a tad optimistic...

[Brick]

Do an internet search for "ballistic calculators" and enter the parameters for a .22 LR and see what you get.

And just so you're aware of the 1.5 mile range mentioned is about the maximum for that bullet when fired at the angle that gives the maximum trajectory not quite 45 degrees.

[wa3ra]

Also, if you fire at that angle, the slug will lose velocity until the top of the parabola, then begin to gain speed on its way back down until friction losses and the acceleration curve meet (terminal velocity) and continue on quite happily until it hits something...preferably empty earth.

[elementfreak431]

Also, if you fire at that angle, the slug will lose velocity until the top of the parabola, then begin to gain speed on its way back down until friction losses and the acceleration curve meet (terminal velocity) and continue on quite happily until it hits something...preferably empty earth.

Exactly. It will slow down to a point. The gravity will take over and the bullet will start accelerating at 9.8 meters per second until it hits something or reaches its terminal velocity

[BandanaBandit1]

Too much complicated math for me

[cptdco]

Too much math for me also, but adhere to Rule #3 and avoid any problems: "Always be sure of your target and what is behind it."

[Yoder]

From what I've read terminal velocity for a 30-06 bullet is 200 mph. I'm sure a .22 is less, but lets use 200. That's about 300 fps with a 40 gr bullet. So if you shoot a bullet straight up at 1200 fps it's coming down around 300 fps. That's not killing anyone. My kids airsoft gun shoots faster than that. Now if you shoot it at an angle, that's a different story.

[Brick]

From what I've read terminal velocity for a 30-06 bullet is 200 mph. I'm sure a .22 is less, but lets use 200. That's about 300 fps with a 40 gr bullet. So if you shoot a bullet straight up at 1200 fps it's coming down around 300 fps. That's not killing anyone. My kids airsoft gun shoots faster than that. Now if you shoot it at an angle, that's a different story.

There's a difference between shooting straight up and shooting on a trajectory. In the case of straight up, the bullet must completely stop at its' maximum height. It then falls with only the acceleration of gravity moving it along (32.2 ft/sec^2). In case of a bulet fired at an angle there is a component (reduced to be sure) of the original "launch energy" throughout its' flight.

[legendarylorot]

From what I've read terminal velocity for a 30-06 bullet is 200 mph. I'm sure a .22 is less, but lets use 200. That's about 300 fps with a 40 gr bullet. So if you shoot a bullet straight up at 1200 fps it's coming down around 300 fps. That's not killing anyone. My kids airsoft gun shoots faster than that. Now if you shoot it at an angle, that's a different story.

p1=m1v1
p2=m2v2
p1=x(p2)

v=300

m1= Average airsoft pellet = .12 g or 1.851883 grains
m2= Federal bulk .22lr = 45 grains

45/1.851883=24.2995913

Thus, your typical .22, when shot straight up, is approximately 24.3 times the momentum of your kid's airsoft gun.

[Brick]

Too much complicated math for me

But, the math (really it's physics with the math playing backup) is what makes it fun.

In all instances:

Force:
F=ma

Kinetic Energy
Ke =1/2mv^2

Momentum
p = mv

Now you might have to some fancy manipulation (fanipulation?) with conversion factors to or from grains to slugs but the equations themselves are pretty simple.