9mm Conversion of the PPSh-41

The Germans in WWII took captured PPShs and converted them by inserting a 9mm barrel and a magazine adapter to accept MP 38 and 40 magazines. No modifications to the bolt face was necessary. The German designation for the 7.62x25 PPSh was "MP717(r), and for the 9mm conversion "MP41(r)". A fellow PPSh enthusiast from Canada told me he spoke with a German Waffen-SS vet in 1965 who stated that while on the Eastern front he received 4,000 units of 9mm barrels and mag adapters to be changed by the Army's Armory in the Ukraine, solely to be issued to "friendly" Ukrainian Security Guards, who the Russians considered "collaborators". The reason, he stated, was every German soldier, when they saw a PPSh in someone's hand, even if they were wearing a German uniform, would open fire at once. This he blamed on the numerous partisan attacks. However, when they saw the straight MP 38/40 stick mag instead of the curved PPSh magazine or the drum, they wouldn't instinctively open fire. He also mentioned that the Army and Waffen-SS had large stockpiles of captured 7.62x25 ammo which they promptly blew up.
With the threat of stopping the importation of 7.62x25 always present, I decided to follow the German example and make a 9mm barrel. This way I could plink and shoot my PPSh with 9mm and save my Tokarev rounds for competition. In 1990 I bought a 9mm barrel blank from Brownell's. Using my 7.62x25 barrel as a guide, I had it turned down and then used a 9mm chamber reamer. The chamber will be tighter than it should be; ie., pistol chambers are tighter than most subgun chambers; therefore, I had the chamber made slightly larger. It is also important to radius the chamber mouth and ‘break' the bottom edge for smoother feeding of the straight walled 9x19 cartridge. One advantage of the Tokarev bottleneck round is reliable feeding. The straight walled 9x19 can be more finicky. The real danger is the top ejection port of the PPSh !!!! If you have a failure to chamber properly and the fixed firing pin ignites the round out of chamber, the brass fragments will rocket back towards the shooter's face!!! I have experience with this!! My PPSh works very well in 9x19, but only after a lot of experimentation, a couple of trips to the doctor's office to get pieces of brass taken out. I hope you can learn from my mistakes to avoid any injury. Very important to ‘break' the bottom of the chamber mouth with a dremel tool to make a "mini" feeding ramp.(Part of the problem with 'out of battery' ignition was due to my 9mm sizing die not set to fully size the case. After setting the die so it would touch the shell plate on my Dillon 550B, I started using a case gauge to check the reloaded 9mm. Any that stuck up even slightly above the gauge, I set aside. I found that 5-6% of the 'full sized' reloads didn't pass the gauge. Shooting only the rounds that pass the gauge appears to have solved the above noted problem. If you don't have a 9mm case gauge, you could use the 9mm barrel to check your reloads.) The last step would be making the exit hole on the muzzle brake slightly larger to accommodate the .355 diameter 9x19 bullet.
Also verboten is using blunt nosed or hollow point 9mm rounds. They absolutely will increase the probability of 'out of battery' explosions.
No need to modify the drums, they will work fine as is. The stick mags will also work, but you have to try each one individually to check for proper functioning. Make sure when you are trying different magazines for functioning, to hold the weapon so that the ejection port is facing at an angle, thereby if an 'out of battery' firing occurs, the resulting brass shards will not propel in your direction or toward someone standing next to you. There have been many who have converted the PPSh to 9x19 with none of the problems as I have mentioned above; however, I feel it is important to mention what happened to me so you can be aware of potential dangers and thus avoid any injury. This is a viable and worthwhile endeavor. I have been shooting my PPSh for several years now in 9x19 and 9x23 with no problems; i.e., 'out of battery' ignitions.