17-04-2014, 07:20 PM
(This post was last modified: 17-04-2014, 10:26 PM by Drew Phipps.)
The problem I referred to in a former post, is that of photographic perspective. Closer objects look bigger than far away objects. Since photos are 2D, our binocular vision can't help us as we are used to. So subtle differences in position might make photographic measurements less reliable.
The good news is, that objects don't change their relative proportions when they get smaller or larger (closer or farther away). An object that is 3 feet long and 1 foot wide will always display that same 3/1 proportion no matter how much it is magnified or reduced. It will also have that same proportion whether measured in feet, millimeters, light-years, or pyramid inches. Using Bob's excellent history and technical specs (and Fraziers' WC testimony) we see that a MC rifle bullet should be 29.21 mm long and 6.78 mm wide, a proportion of 4.31 (L) to 1 (W). No matter how we measure it or how we reduce or enlarge it we should always get the same proportion.
I used the 4 pics (which I am hopefully attaching to this post) to count pixels. I used maximum magnification to count pixels, and the pixels are easily visible at top magnification. (I concede that I could have miscounted a pixel or 2.) I counted the length thru the center line of the image from tip to tail. I realize that this method of length might actually produce a count a tiny bit greater than the actual size, in that the rear pixels of the image (at a rear edge is the point are closest to the camera, and the front pixels of the image (at the tip of the nose) are slightly farther away from the camera. (Someone better at math, and cameras, than me will have to tell you how much error that introduces.) I measured the width at the widest point just aft of the nose, to avoid any distortion from the tail end flattening of the round
Photo 3317 L = 381 pixels W = 86 pixels proportion = 4.43
Photo 3318 L = 374 pixels W = 83 pixels proportion = 4.51
Photo 3319 L = 362 pixels W = 82 pixels proportion = 4.41
Photo 3320 L = 381 pixels W = 84 pixels proportion = 4.54
Average proportion = 4.47
These proportions are about 4% higher than they should be, if the 4 photos were of the same bullet. That means that if the pictured bullet was truly a MC 6.78 mm caliber bullet, it would measure 30.54 mm in length (which is wrong). If the length of the bullet was actually the WCC MC length of 29.21 mm, the caliber would be 6.53 (which is also wrong, but corresponds to .257 ammo). I think, however, that the true conclusion is more shocking. If I was a betting man, I'd bet that photos 3317 and 3319 show a different bullet entirely than photos 3318 and 3320. And I'm hoping that Bob is going to help me nail down exactly what kind of bullets these might be.
There are also problems with the twist ratio engraved on these bullets. Assuming that the scale measurement is in fact correct, the twist ratio on these pictures is faster than the 1 twist per 8 inches that the Italians used for one of their 2 kinds of mil spec barrels. If I pretend that it's a single WCC MC bullet, and use Bob's data for land and groove width, I get a spin of 1 per 7 inches, but a couple of the photos individually appear to show a faster spin rate than that impossible if it's all the same bullet. (The other type of mil spec barrel would have been the sawed-off progressive twist 31 inch barrel from the original MC long rifle, which had a much slower rate of spin than 1 / 8 inches for the 21 inches closest to the chamber.)
I cannot say at what point these images were procured and became something other than what they claim to be. (They are .gif, which wasn't invented until after the WC and the HSCA.) It could be pre-Warren Commission, or some or all of these photos might have been added to the National Archives, or substituted later. Or, since this is the internet, these images might not be accurate representations of what is in the National Archives at all. But it is clear that these pictures are not a single WCC round fired from a MC 91/38 rifle.
Forgot my second conclusion:
IF we assume that this is all the same bullet and IF we assume that the ruler in the background is the same distance from the camera lens as the bullet, then the actual measurements of the bullet average out to length 28.8 mm and diameter of 6.44 mm, which corresponds to a .254 caliber bullet.
The below photos appear to have been downloaded from NARA, which does contain apparently identical .gif images, but I did not download them myself directly from NARA.
The good news is, that objects don't change their relative proportions when they get smaller or larger (closer or farther away). An object that is 3 feet long and 1 foot wide will always display that same 3/1 proportion no matter how much it is magnified or reduced. It will also have that same proportion whether measured in feet, millimeters, light-years, or pyramid inches. Using Bob's excellent history and technical specs (and Fraziers' WC testimony) we see that a MC rifle bullet should be 29.21 mm long and 6.78 mm wide, a proportion of 4.31 (L) to 1 (W). No matter how we measure it or how we reduce or enlarge it we should always get the same proportion.
I used the 4 pics (which I am hopefully attaching to this post) to count pixels. I used maximum magnification to count pixels, and the pixels are easily visible at top magnification. (I concede that I could have miscounted a pixel or 2.) I counted the length thru the center line of the image from tip to tail. I realize that this method of length might actually produce a count a tiny bit greater than the actual size, in that the rear pixels of the image (at a rear edge is the point are closest to the camera, and the front pixels of the image (at the tip of the nose) are slightly farther away from the camera. (Someone better at math, and cameras, than me will have to tell you how much error that introduces.) I measured the width at the widest point just aft of the nose, to avoid any distortion from the tail end flattening of the round
Photo 3317 L = 381 pixels W = 86 pixels proportion = 4.43
Photo 3318 L = 374 pixels W = 83 pixels proportion = 4.51
Photo 3319 L = 362 pixels W = 82 pixels proportion = 4.41
Photo 3320 L = 381 pixels W = 84 pixels proportion = 4.54
Average proportion = 4.47
These proportions are about 4% higher than they should be, if the 4 photos were of the same bullet. That means that if the pictured bullet was truly a MC 6.78 mm caliber bullet, it would measure 30.54 mm in length (which is wrong). If the length of the bullet was actually the WCC MC length of 29.21 mm, the caliber would be 6.53 (which is also wrong, but corresponds to .257 ammo). I think, however, that the true conclusion is more shocking. If I was a betting man, I'd bet that photos 3317 and 3319 show a different bullet entirely than photos 3318 and 3320. And I'm hoping that Bob is going to help me nail down exactly what kind of bullets these might be.
There are also problems with the twist ratio engraved on these bullets. Assuming that the scale measurement is in fact correct, the twist ratio on these pictures is faster than the 1 twist per 8 inches that the Italians used for one of their 2 kinds of mil spec barrels. If I pretend that it's a single WCC MC bullet, and use Bob's data for land and groove width, I get a spin of 1 per 7 inches, but a couple of the photos individually appear to show a faster spin rate than that impossible if it's all the same bullet. (The other type of mil spec barrel would have been the sawed-off progressive twist 31 inch barrel from the original MC long rifle, which had a much slower rate of spin than 1 / 8 inches for the 21 inches closest to the chamber.)
I cannot say at what point these images were procured and became something other than what they claim to be. (They are .gif, which wasn't invented until after the WC and the HSCA.) It could be pre-Warren Commission, or some or all of these photos might have been added to the National Archives, or substituted later. Or, since this is the internet, these images might not be accurate representations of what is in the National Archives at all. But it is clear that these pictures are not a single WCC round fired from a MC 91/38 rifle.
Forgot my second conclusion:
IF we assume that this is all the same bullet and IF we assume that the ruler in the background is the same distance from the camera lens as the bullet, then the actual measurements of the bullet average out to length 28.8 mm and diameter of 6.44 mm, which corresponds to a .254 caliber bullet.
The below photos appear to have been downloaded from NARA, which does contain apparently identical .gif images, but I did not download them myself directly from NARA.