M14 vs m14a1 api

Been getting a lot of questions lately about the M14 and M14A1 Armor Piercing Incendiary differences.
From left to right:
FA/45 M14 (T-15?) 147grs 80gr core, 2gr IM-11 Boat tail (Never weighed)
FA/53 M14A1 150grs 62.5gr core, 8.5gr IM-11 Flat base
Also have the differences in M1 and M1 Alternative Incendiary, just incase.
Den/42 M1 136grs 8gr IM-11 copper base cap
Den/42 M1 Alt. 138grs lead base plug


Nice job. With a bonus. Any way to tell the Incendiaries apart without pulling a bullet?


These differences should show up via x-ray - it’s helped me with evaluating nurmerous 7.62x51mm tracer’s, AP’s, API’s etc and identifying the variations in CETME cores. I’ve been fortunate that my dentist and a local vet were prepared to help. The biggest challenge I faced was convincing them that x-rays would be of value. However, once films were processed, everyone was interested in what the x-rays showed.

Nice work Wolfgang


If you know what you are doing (most of us do not) it is possible to tell an M14 from an M14A1 with a magnet. Couple the magnet test with the headstamp and you can usually get it right.

Since the M14 was not adopted until after the war (1946) I’d guess that your FA 45 is a T15 rather than an M14.



Saw your questions on another forum about the FN version that is being sold over at the CMP. The Belgians used the M14A1 flat based bullet. However the steel core is set back a hair further (maybe 1mm) than the US M14A1. This would allow more IM-11 to be used, maybe a grain or 2. I’ve got two on the desk in the middle of cutting with head stamp FN/55. My info came from Chris Punnetts’ book “.30-06”, where he describes the same thing.

Also according to his book, the M14 looks to be an early M14 in a T15 case (because of the date). The T15 would have just a little more lead at the base, that’s why it should have been weighed before cutting. Who knew!

Can’t compete with Paul Smith or Wolfgang, but here is a cut of a FN55 headstamped API I made