.50 M1 Armour Piercing Question

One for the.50 specialists. Does anyone have any drawings, images, reference examples of .50 M1 AP projectiles. From checking Hackley, Woodin and Scranton Volumes 1 & 2 The M1 AP is referenced as 750 grain, 2.41" in length with a knurled cannelure - identical to M1 Ball. They also state that the last lot produced was by FA in Feb 1941. Does anybody have any evidence of RA 42 production of these? Or would an RA 42 headstamped case with projectile matching correct projectile length actually be M1 Ball rather than M1 AP? Any help or thoughts appreciated.

While the .50 is my specialty, and have pulled down hundreds of examples of ammunition to examine projectiles, powder charges, primer designs, etc., I’ve not taken it upon myself to pull down examples of every combo headstamp mfgr and date. Sorry. The examples of .50 AP that I have pulled, the M1 and M2 AP’s match HWS descriptions. The M1 has the knurled not smooth cannelure, is longer and heavier than the APM2.

If your concern is how to tell the difference between an RA 42 round AP M1 vs Ball M1 projectile, yes the black tip would be the only indicator as a live round. Pulling the bullet, ignoring the tip color, the Ball M1 an AP M1 would be the same weight, same length, same cannelure. With an exposed core at the bottom of the jacket, I’d take a small screwdriver and try to scrape the exposed portion of the core. Ball will show a scrape. The AP would not.

That’s about the best I can do, if I correctly understand the intent of your question.


50m2hb - thanks for your reply. We are currently working on the recovery of a B24 here in the UK as part of a US DPAA MIA project. Due to legal constraints here in the UK we cannot perform any proper analysis of the projectiles - we are unable to take any into possession. Most of the ammunition is disarticulated (separated case and projectile) as a result of the crash but there are some examples that it has been possible to match case and projectile - some of these are RA 42 and detailed as my previous description. No tip colouring is present due to degradation. Some of the projectiles are M2 AP and M8 incendiary - these are easy enough to ID. Its the longer somewhat enigmatic possible M1 AP/M1 Ball examples that are the ones trying to ID. The aircraft crashed in June 1944, so it seems a bit odd to be using M1 AP at this date (M2 having been introduced in 1941 and being present as other examples found), but equally odd why M1 Ball would be carried on a combat mission?

Ball wouldn’t be a normal combat load, but with supply challenges, UBoats and such, you’d use what you could get. .50 Ammo, being particular to the US and US supplies to allies, was difficult to keep in inventory in combat theatres at times.


Of little practical use perhaps is that the RA 43 exists with the M1 AP black-tipped bullet

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Thanks 50m2hb & PetedeCoux - all useful info!