A friend of mine picked up an Arisaka type38 carbine in 6.5MM that is nicely customized, but the shell casings are bulged after firing. This is a common issue with Arisakas and most people just live with it.He wants to cut the chamber area off of the barrel and cut a new chamber. Sounds like a money pit to me.
I found the same issue with multiple Arisaka rifles. The first time I encountered it, I assumed something was wrong, but after a lot of reading through very old articles I found this was a known issue with these rifles. A couple of the old gun writers who experimented with these rifles commented on it.
I use ample lube, and have no issues resizing therm.