FBI Evidence Proves Oswald's Ammunition was not Capable of Sufficient Accuracy to Kill JFK

[John Lewis]

That alone proves that the combination of a .264" bullet fired though a barrel with a .268" groove diameter is not automatically grossly and chronically innaccurate. There is nothing about the Carcano barrel which would change that.

JL.

Did you read this?

Apparently related and current article:
http://kegisland.com/carcano-ammo-warnin...tizan.html

"I wondered why my 6.5 Carcano short rifle was sending bullets all over an area approximately several feet in diameter at 50 yards, so I checked the bullet diameter.

The Prvi Partizan - manufactured 139 grain FMJ 6.5 Carcano ammo on hand measured a .2635 inch diameter. 6.5 Carcano bullets should be .268 inch in diameter. A second box on hand measured the same bullet diameter. "

*edit: To be clear that website seems to be confirming Bob's point and countering yours John. Most importantly he's using a 6.5 Carcano.

Yes, it was mentioned further up the thread before I got involved.

This is not 'proof' that the particular rifle is behaving like it is purely due to the size of the bullet. The bullet design used by PPU is very different to the one used in Italian service ammo and it is a different weight. The bearing surface of their 139grn bullet is much shorter than that of the 160grn bullet which was alleged to have been fired from Oswalds rifle. The 6.5x52 (Carcano round) and 6.5x54 (Mannlicher-Schoenauer round) rounds use a very long, blunt nosed bullet, a type which PPU do not make. They simply use the same bullet they put in their 6.5x55 Swedish ammo as it's what they have on hand.

The Carcano rifle utilises a very fast rifling twist, as does the 6.5x54 M/S round, which is needed to stabilise the very long 160grn bullets. PPU 139grn ammo has a muzzle velocity of 2,500fps, that is at least 300fps faster than the ammo it was intended for with it's heavier bullet. The PPU bullet has a much smaller bearing surface (the bit which engages the rifling) so has a much greater chance of not engaging it at all. In addition, that bullet is small even by modern standards.

What I think is happening is probably this; the bullet has further to travel before it hits the rifling because it is shorter and its bearing surface is significantly further away from the throat. By the time it comes into contact with the rifling it is already traveling at a significant velocity because of its further travel. Because of its velocity, the fact that it is small even by modern standards (.2635") and that it has a small bearing surface it cannot grip the rifling and the rifling simply shaves off jacket material rather than allowing the jacket to be engraved. This means that the bullet is not being spun and so cannot be accurate.

I would put fair money on that particular bullet being perfectly accurate in that rifle if it were loaded into ammo with a lower muzzle velocity. That way it is exposed to far less stress when it engages the rifling and would have a much better chance of engraving it properly.

It would be interesting to see whther their load using a heavier bullet of 156grn, which I'm sure will be the same diameter, is accurate in this chaps rifle.

JL.

And yet, Prvi Partizan bullets are recovered, after being fired from a Carcano rifle, that show nicely engraved rifling marks on the bullet. According to you, that is evidence the bullet was spun and the jacket not just "shaved off" (what a silly notion).

What is your source for that information? The chap who wrote the article makes no mention of that.

Have you ordered any Hornady bullets yet so that you can measure them?

Have you accepted the fact, the legally mandated fact, that 6.5x54mm MS rifles do indeed have a groove diameter well in excess of .264"? You did, after call, call me a liar when I said (repeatedly) that my rifle had a .268" groove diameter.

JL.