M20 API-T
50 Caliber Armor Piercing Incendiary with a tracer element. Came to life early in W.W.II, for
decades this was the ultimate in versatility and performance. The hardened steel core is
only slightly lighter than the M8 API because of the cavity necessary for the tracer
element. The Incendiary mix is 18 grains if IM#11, so the incendiary effect is slightly
greater than the M8 API. The tracer element, however, is tiny compared to the M17 so to
get the desired length of trace a 
more efficient tracer material is used. This new tracing
material gives a dim trace for the first 300 yards, then full bright for the remainder of
the 1750 yards. Projectiles are lighter than other comparable service rounds, weighing on
about 620 grains. Tips are painted red and silver.
These M20 projectiles 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.
We shoot these out of the M2 machine gun. Of the several thousand we have fired, only about 10% have traced! The greatly reduced tracer cavity in these projectiles requires a different tracer material and igniter element than the standard M17 Tracer. Also, this is a boattail design rather than flat base like the M17, so the surface area of the igniter exposed to the burning propellant gasses is considerably smaller. Over the years, this new igniter element has gone flat (inert) and no longer reliably ignites the tracer. We use ball powder for our loading, and admittedly using IMR-5010 does help increase the percentage of tracers that light properly, but with the bullets we were using the small increase in performance did not merit the higher cost and inconvenience of using the IMR powder. The Government is pulling these down, and they are mixing the old stale tracer bullets along with the new ammunition that may be pulled apart just because it lost it's lot number. So sometimes you get lucky and get a batch of late date projectiles that trace and other times you get old projectiles that won't trace. We have had customers that tell us these things work fine for them, but we have shot up at least 5000 of these and only one out of every ten traced. They all flash on impact.
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