Tanaka Kar98k nozzle replacement options

[Impulse]

Got a bit of a quandary and wanted to get some extra opinions on this. It's an important one because not only is it an incredibly rare piece, but it also holds sentimental value for its owner.

 

I've recently been given a friend's pre-ban Tanaka Kar98k G33/40 to work on (the short, mountain trooper version; it's lovely!), as it's very inconsistent and while I'm not a "tech" as such, I have a reputation of knowing a lot about these Tanaka rifles and their clones since I've worked on several of my own, so he has given it to me to look at. The cause of the inconsistency is very easy to identify, but not easy to solve. The old Tanaka rifles had awfully short nozzles that didn't go into the hop unit properly, meaning it didn't push the BB into the right place and you can even hear it rattling around if you load it and then shake it around a bit. This picture shows what I mean (taken from the m700 owners facebook group):

 

The nozzle is definitely too short in his kar98k. I removed the bolt from my PPS Kar98k, which is a clone of the Tanaka, and the comparison is obvious. Insert joke of "you vs the guy she tells you not to worry about". First pic is the Tanaka, second pic is the PPS

 

 

The issue I'm having is I can't just replace the nozzle easily. His Tanaka is a pre-ban, so the inside of it is threaded so that he can fit small restrictors to limit the power. This is how the really old pre-ban Tanaka Kar98k rifles did their power adjustments. The PPS bolt has a grub screw on the inside, accessible with a thin screwdriver through the nozzle, that regulates the power that is super easy to adjust; you can see it in my picture through the intake rubber because I was using it 1.1J in very warm weather last time I used it, so I had to have it almost all the way out. If I simply removed the Tanaka nozzle for a standard, but longer nozzle like I would on an m700 (they adjust power differently), then he'd have no way to regulate the power outside of using different gases, which isn't good enough and he'd struggle to keep it below 1.1J during the warmer months even on 144a due to these rifles having fairly long inner barrels and gas guns joule creeping to hell. Plus it's not possible to fine tune there and you will come up against situations where green gas might be 1.3J, but 144a is only 0.8J. This is how the power adjustment is done on his pre-ban Tanaka Kar98k (he has three different inserts of different sizes):

 

 

So, at the end of all this I have come up with two potential solutions:

 

1. Replace the entire bolt, or at least the front end, with a PPS Kar98k bolt, as it is a clone. This will have an extended nozzle and an easy to adjust grub screw to regulate the power; all the owner would need would be a long, thin screwdriver, but those are incredibly cheap to pick up and he may even already have one. The downside of this is that nowhere even has a PPS Kar98k bolt listed on their shop, outside of Tiger111hk and they're out of stock and who knows when they'd be back in stock. Furthermore, from what I can test with my bolt, it doesn't quite fit in properly so I think I'd probably have to get a fresh bolt and then modify it somehow to fit. I am not 100% sure yet whether it's the nozzle width or the dead of the bolt that doesn't fit, and honestly I don't really have the tools for this. I have sent airsoftworld an email asking if they can directly order a bolt from PPS, as they stock the Kar98k itself (out of stock) and will still experiment because I'm not 100% sure if my bolt is stock, but if it doesn't fit I'd just keep it as a spare for mine.

 

2. Get someone to CNC machine a custom nozzle for the Tanaka bolt. Obviously this is going to require some pretty precise machining, especially since it would need to have the threaded inside for the restrictor valves. The upside of this is that I can get the ideal nozzle made, with the same restrictor valves to regulate power. The downside of this is that I have no idea how much this custom work would cost, nor do I know anyone who could do it. 

 

So... what are your thoughts on all this? I'm thinking that it's probably going to have to be a CNC job for a custom nozzle, as the PPS bolt option seems like it's actually more trouble than it's worth. Does anyone know or can recommend a good person or company I could contact for a custom job like this?