45 ACP Headstamps

Did Twin Cities Ord. Plant produce 45 ACP during every period that they operated or just during 1941-45? I have one stamped TW 5 (1955) with a steel case but that’s the only one I havebeen able to find in the 50"s time period.I also have a 45 Blank stamped SL 4 (1944).I thought that ST Louis only mfg. 30 & 50 cal…Can anyone set me straight on this info.

Just to confirm they are .45 cases and not cut-down .30-06, compare the rims and grooves next to known .45 examples.

Twin Cities did not produce .45 ammunition during WWII, or at any time other than the mide 1950s. Your .45 blank headstamped “S L 4” is a movie blank made from a .30-06 case - it was not manufactured as a .45 by St. Louis Arsenal. They did not make .45 ammuntion at all.

While comparing the extractor groove and extractor-groove bevel of your blank to those of other .45 ACP rounds and .30-06 Rounds may help, it is not always the case. Some blanks are made from .30-06 including having the extractor groove and bevel worked over to 45 spec. It is, though, one more way to tell with some of them. On those in my collection made from .30-06 or .308 cases, 8 out of 18 have been so altered, with two others questionable, asa to whether they have been altered or not, or just originally had slightly wider extractor grooves than usually found on .30-06…

Thanks for the help.