Ahhh... that pin. That pin is the bane of all who would seek to remove it. The holes in the ferrule through which the pin is inserted are drilled to allow the pin to be countersunk. In fact calling it a pin is somewhat of a misnomer. The word "rivet" would be more precise. I recently ruined (as has been mentioned above) the wood handguard on a '50 Tula attempting to remove that pin. In fact, I also bent the gas tube slightly in the process of pounding on the pin, but not enough that it couldn't be saved. It was at that point (as has also been mentioned above) that it was necessary to drill the ends of the pin to finally get it out. On the '50 Tula the left side of the ferrule (shooters left) was the offending end, with the deepest countersink. The other side had been "smeared" over and filed flush. Once the ends were "carefully" drilled below flush with the ferrule, the pin came out easily with a punch. I noted, and have seen in several videos as well, that the pin was actually bent once it was removed. It wasn't bent during removal, but rather I believe it was bent after insertion and due to the "riveting" process that Comrade Uri applied during its original fitting some 65 years ago.
Once removed, the pin was useless. For reference, the original pin diameter is 2.8mm (.110") I used a 1" nail (~.100" dia.), carefully cut to length, the head filed and shaped to match the countersunk hole on the left hand side of the ferrule, the opposite end "peened open" with a centre punch to fill the countersink on the right. I then used a rifle file to smooth the ends flush with the ferrule. The job isn't as tight as Uri's efforts left it, but it's more than secure enough. In fact, while not recommended or ideal, the ferrule can be used without the pin at all as it (the ferrule) is captive once installed.
