Congratulations!
Jim Watson and Jim Keenan,
You have correctly identified the pistol in my photo. This is a little known and seldom seen 9mm designed and developed under at least two government contracts between 1948 and 1951. Perhaps these pistols were also involved in the later trials that included the Colt T-4 and prototypes from S&W and Inglis.
There were three different designs two of which had 7 shot single column magazines and the final design had a 13 shot magazine the design of which was a modified form the Browning Hi Power magazine.
Unfortunately the government specified in the contract that this was to be a blowback design. Despite stiffer recoil springs and weights soldered t the slide the recoil was not acceptable. On the early pistols High Standard did experiment with one and two annular grooves in the chamber which actually worked quite well but the final contract prohibited the grooved chamber. I have heard that this was because the government felt that steel cased ammunition would work differently than brass cased ammunition. but this may be just a story.
The government did indeed have several variations of the 9mm round manufactured for this pistol most with lathe turned bullets. I have in my collection four of the about ten different versions if this "T-3" ammunition. I find it interesting that some of the ammunition was hollowpoint.
Here are photos of the other side of the previously pictured pistol which is one of one and probably a concept piece for the other prototypes. The three other designe were produced in lots of four pistole each. there may be a few more of the double coulmn type.
High Standard T-3 Type 0 1 of 1 no serial number
High Standard T-3 Type 1 Serial number 3 of 4
High Standard T-3 Type 1 Serial number 3 of 4
High Standard T-3 Type 2 Serial number 4 of 4
High Standard T-3 Type 2 Serial number 4 of 4
High Standard T-3 Type 3 Serial number unknown