The M1928, M1928A1, and M1A1 all have a slightly incorrect reload animation, at least with stick magazines
https://www.youtube.com/watch?v=D53opaeollQ - showing M1A1
https://www.youtube.com/watch?v=9spzqY4PxOM - showing M1928A1, extrapolate that M1928 works the same
They do not lock back on a drum magazine, but they do with stick magazines. At the very least, the M1A1 should have a reload without pulling the bolt back, as it's only necessary if you manually release the bolt after removing the magazine.
For the M1928(A1), I'd argue that stick magazines were still far more common by the 1960s, so the same should be done. NIArms and RHS have shown that different reload animations depending on magazine are possible, so a drum magazine reload could have a bolt pull, while a stick magazine reload could skip it.