50 Caliber M8 API
The M8 API (armor piercing incendiary) was put into service in 1943 to replace the M1
Incendiary, and is still in service today. The M8 is built nearly identical to the M2
Armor Piercing except the M8 has 12 grains of incendiary mix (IM#11) in the nose instead
of a lead filler, and a lead caulking disc in the base acting as a seal. Having the same
hardened steel core as the M2, the M8 matches the armor piercing capability of the M2 with
the added 
advantage of incendiary effect. While it has considerably less incendiary mix
than the M1, the performance of the M8 was greatly superior to the M1 because of it's
ability to penetrate the target and ignite the material inside rather than just flash on
the surface like the M1 often did, making for a greater first shot effect. Bullet
weight is about 649 grains, and identified by silver tip paint.
These M8 bullets have been pulled from US GI W.W.II dated ammunition on the "old style" bullet pullers. This machine splits the case neck and then gently removes the projectile. As a result of this operation, there is 1 small line on the projectile from a point just slightly ahead of the cannelure down to the beginning of the boattail, leaving only a negligible mark sticking out of a loaded case. These projectiles have all been run through a set of draw dies to insure proper diameter, and eliminate the high spot caused by the split line.
Pyrotechnic performance of these projectiles is only slightly less than the M1 Incendiary. The flash varies exponentially with the amount of fuel, so while the M1 contains 3 times the incendiary mix of the M8, the flash is only about 30% larger. These M8 are also safer ( we have fired 20,000 plus rounds and not yet had a muzzle flash,) but they are less sensitive. When shooting through steel drums, they flash on the second surface creating a flash inside the drum. Similarly, when shooting vehicles, the projectile generally penetrates the skin and detonates inside on another sheet metal surface. High speed photos show the tip breaking off with the first penetration, exposing the incendiary mix which then detonates on the second impact. Plywood targets are merely penetrated with no flash. They will flash on a dirt backstop, but unless they strike a rock the projectile will more than likely penetrate about 6" into the surface before flashing, making only a small visible flash. But if your target is rocks, concrete, or heavy steel, these bullets provide a spectacular show!
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