T, XM, and LCAAP designations

Another thread on the 45 ACP XM261 reminded me to ask this question.

The old “T” designations were replaced with the XM-M system in 1958. XM-M was supposedly replaced in 1970 with the LCAAP “method” of internal test numbers. When FA closed in 1977 all in-house designations where transferred to LCAAP.

Question - Does anyone have any idea of how the LCAAP method worked? Is there a list such as we used to be able to find for the T and XM-M designations? What system, if any, is now used?

OK, that’s three questions.

Anyone? (that’s four).



Anyone? (that’s four).


A fifth question: what’s the meaning of LCAAP?

Lake City Army Ammunition Plant

Sorry, I thought everyone knew that. ;(