Here are four pictures of a .416 Woodleigh solid recovered from a sand pile. Notice that the jacket is sandblasted away in a ring all around the nose, but the nose itself is intact. Any theories on how that happened?









Let's hear your ideas.

Best,
Joe

The sand at the 'point' simply pushed ahead of the bullet, while the rest was 'moving' out of the way.

The nose of the bullet would get the most "sanding" when going into the pile, but I have no idea why the exposed lead isn't flattened.

The jacket was eroded by the abrasiveness of the sand. Notice the jacket plating is still intact on the nose. Remember the jacket of the Woodleigh is steel that is plated. Has the Steel been eroaded away? The main thing is that the jacket did not fail and open up. Woodleigh solids have a good reputation. Check the nose of the bullet with a magnet, it does not look like the lead has been exposed, only the plating has been worn away.
Hard to tell form the photo.

[ 03-29-2003, 08:04: Message edited by: N E 450 No2 ]

Mighty soft jacket huh?

Woodleighs are tough bullets. I'd suggest you try one through a bunch of phone books. I think you'll get your expansion. If the sand pile was just that, a pile of loose sand it might not have provided a good media to force expansion?

What was the range?

Rusty
We band of brothers!

Nextjoe, it has to do with fluid dynamics. The entire subject is very involved. The exposed steel jacket is due to the DRAG of the bullet through the sand. Essentially, the only portion of the bullet, which the sand contacted with any significant pressure, was the area in which the jacket has been eroded away exposing the steel. The pressure distribution was such that the sand evidently did not contact the tip. The pressure at the very tip of the bullet is actually rather low, relatively speaking that is. By the way, it is very obvious that the bullet was travelling substantially below the speed of sound in the sand.

The physics at work here are rather complex. It would be very difficult to explain in layman's terms the physics involved without pictures, etc, etc.

You might find a website called "how things work" to be beneficial. I suggest you look that sight up and perform a search on how airplanes fly, how aerodynamics works, and how bullets fly. One of those should get you some easy to understand feedback. The basic principals at work are the same for a bullet in flight as an aircraft so if you can understand how the plane flies at supersonic and subsonic speeds you will understand the bullet as well.

Axel

Joe,

I think the copper plating has come off the ogive because the point was "square on" to the sand.

The ogive is getting the abrasive effect of the sand (hence plating is gone) and also creating a bow way so the sides of the bullet did not get to hard a blasting.

Mike

The grey showing is steel, not lead. The sand "blasted" the brass/bronze coating off, but didn't harm the steel. The area of most wear is the area where the sand had the most scrubbing on the plating.

It is a solid. It looks pretty much like you'd expect it to look. Sanded on the front without any mushrooming. Ku-dude

I think Axel's got it right. The fluid flow of the sand caused very little contact at the tip, and much more just there where the steel is exposed.

I recall a picture from an old engineering text on fluid mechanics. It showed a bowling ball (I'm not making this up) in a wind tunnel test of air flow. The smooth surface caused significant turbulence pretty high up on the radius of the ball - i.e. close to the front. You'd think that the smooth surface of the ball would promote the smooth flow of air over it's surface, and the picture was there to provide dramatic proof of how wrong that assumption is.

Then they glued a fine sandpaper on the surface of the ball, and the result was much smoother (laminar) flow of the air over the ball. The reason was that the grains of sand set up a boundary layer, over which the fluid (air) traveled much more easily.

Translating that to the Woodleigh, and I can see the sand scouring out it's own roughened up area to create a boundary layer, then the sand flowed quite smoothly over the rest of the bullet.

Makes sense to me, anyway.

Hi I make my own solids out of brass and here is what I see on your bullet. Sand-dirt stops the rotation of the bullet very quickly and they try to tumble. That is why you see areas on the sides and back of the bullet that have wear marks on them. I often recover bullets with perfect rifleing on 1 side and the other all worn of on the the other and this is what I see on you example.