Monday, February 04, 2008

M1 Carbine load test

Results, interesting

Today being one of those nice days we get this time of year, and having enough jugs to make three, maybe four test shots(I thought) to try out the .30 Carbine load I worked up, I loaded up and headed for the range. Few days ago I'd put together my own 'Box o' Truth', displayed below on the dolly.

Sheetrock slightly the worse for wear. The dolly because I had no desire to carry a minimum of three gallon jugs of water and the box 50 yards for the first shots, then 100 for the next.

Set it up first at 50, aligned by eyeball with the bench, then made two shots on paper to make sure no gremlins had messed with the sight since the last outing for the Carbine. I'd stuck a black bullseye low on the first jug, and- since the box would hold five jugs- I'd filled it, figuring it'd save carrying one or two out for the next shot. The jugs are 6" square, and I put the aiming point low to make sure I'd get the full width.

Having nobody available to shoot pictures I have no dramatic 'jug exploding' pics. There was a very nice splash, and when I walked down to check found
jugs 1 and 2 pretty well torn apart,
jug 3 split on one side, hole on the other,
jug 4 with a hole on each side,
jug 5 with a hole on one side and the spent bullet in the bottom, looking like this:

Interesting. It penetrated right at 24" of water; the hollow point didn't upset at all that I can tell, but the jacket split down one side and the core is loose inside(something I did not expect from this bullet).

I now had only enough jugs for one more shot. And the wind was picking up so I decided to make another at 50, and try 100 later when I had more jugs and the wind wasn't gusting so strong. The visual was the same, and the number of jugs penetrated and their condition duplicated the first shot, again the bullet in the bottom of #5:

This bullet deformed worse than the first, the jacket ripped open and the core almost falling out. And again, you can see that hollow point looking unchanged(except for pointing sideways).

This is not the result I expected. I'd figured, this bullet at this velocity, I'd get one of three:
Bullet expanded somewhat or
bullet deformed somewhat or
bullet looking much like unfired.
I've had several people say the bullet, at just under 2000 feet per second, would not expand or deform at all. Well, that was wrong. But it didn't expand anything like I'd hoped for/expected, either. And it gave more penetration than I'd expected(note to self, in future try this with ball to check penetration).

At 50 yards, probably a realistic distance for shots in many SHTF situations, I think this load would do the job: that bullet would leave a mark. At 100? Guesswork until I can get more jugs together. This bullet should hold velocity fairly well, so might get similar results, but...

We'll see.

Note: reason for the jugs of water instead of ballistic gel? Have you ever looked up how much that stuff costs?


Anonymous said...

Hmmmm......probably time to try the same test with other bullets. A hollowpoint that doesn't open up is just an expensive FMJ.

Mattexian said...

On one of yesterday's reruns of Mythbusters, they fired into a swimming pool to test the theory of hiding underwater from a shooter. Several times the bullets just shredded into metal flakes and drifted down to the bottom after the initial impact with the water's surface. Maybe the conclusion here should be, water isn't that great a testing medium for bullets?

Firehand said...

For handguns, it's actually one of the standards.

'Course, at 1925fps, it might be overpowering things a bit.

Anonymous said...

Saw the Mythbusters bullet/water thing a few years ago when it first aired; hardly scientific research. IIRC, one of the rifles they used was a Garand, with the muzzle about 6-8 ft off the water. No mention of muzzle velocity, bullet type, etc.

I'd be interested in seeing it done again, this time in 100FPS increments from 850 to 3200, with a few different calibers and projectile types (850 is 45 ACP, 2850 covers the '06, 3200 is 5.56 from a 20" tube, and there are a whole bunch in between: 7.62X39, 9MM, 12 gauge slugs, etc.). I suspect the fragmentation will stop once velocity at surface impact drops below about 2300 for most rifle bullets, and the handgun stuff will stay intact.

My guess is that someone in the .gov already has those data.

Firehand said...

If I remember right, they used ball with the Garand, which would mean muzzle velocity of somewhere between 2800-2900.

Would be interesting, at what velocity does the breakup of a projectile begin? And yeah, there probably is a thick book of test results somewhere in an archive on the subject.