I was the HQ AFOSI Marksmanship Manager and USAF Special Investigaions Academy firearms instructor from early 1974 until fall of 1977. Our issue handgun was a 3" heavy barrel S&W M-36. We begun to see the PGU-12B ammo sometime in 1976. We shot our training weapons extensively and we quickly learned that the PGU ammo was shooting the M-36s apart. We sent several to the Air Force Marksmanship gunsmiths at Lackland AFB, TX and they confirmed our suspicions and recommended that we terminate the use of PGU in the J framed Smiths. Since the guns in the field were usually only fired a couple of times a year for agent requal it took a little longer for the problems to become evident, but not too long. Just before I was reassined from HQ I put together a selection team to select a new handgun. I selected several team members who where 1911 fans and since my successor was also a 1911 guy they selected General Officer size 1911s that were built by the Lackland AFB gunsmiths especailly for OSI use. I'm not sure how long they were used but this was also about the time that DOD adopted the 9mm DOD wide. To my knowledge, AFOSI now uses the M-11, Sig.