As is the case with so many regiments, Todd's AME has not information on the weapons of the 42nd Ala. Infantry.
All I can share with you at this point is some other research that turned up the following:
The Muster Roll of Co. K, 42nd Ala. Inf. for May 16, 1862, says Company K's station was Columbus, Mississippi. The report says the men had little clothing, no accoutrements, and had no arms. Their military appearance says "good physique" and that they were " raw recruits and undisciplined but had capacity for learning."
They are listed in a Consolidated Report dated December 14, 1863 as follows:
42nd Alabama, Lieut. Col. Thomas Lanier
248 effective total
311 total present
676 aggregate present and absent
247 number of arms
80 rounds of ammunition per man