The Hamilton was a handgun entered into the Swedish military pistol trials of 1903, where it competed against guns like the Luger and Colt/Browning 1903. The Hamilton was a simply blowback action chambered for 6.5mm Bergmann, although it did have the interesting and unusual feature of a bolt which pivoted on a round path during recoil rather than traveling linearly.
The Hamilton’s loss in military trials to the Colt 1903 is not particularly surprising, as it was heavy, underpowered, and rather awkward to handle. It never saw commercial sale on any scale, either.
Edited to add: A Swedish collector contacted me with some addition details about the trials that the Hamilton participated in. There were more pistols entered than I had realized, including several different types of Colt and Browning designs which are easily confused. The full list of entrants is:
- DWM Luger in .30 Luger
- Browning M1900 in .32 ACP
- Colt/Browning M1903 in .380 Browning Short (.380 ACP)
- Mannlicher (presumably M1900) in 7.63mm Mannlicher
- Mannicher carbine-pistol in 7.63mm Mannlicher
- Hamilton in 6.5mm Bergmann
- Browning M1903 in .380 Browning Long
- Frommer in 8mm
- Russian Nagant M1895 in 7.62mm Nagant
- Swedish Nagant M1887 in 7.5mm Nagant