Question for the Valmet builders

[Fuzzy Wool Hat]

Hey guys, I'm considering doing a build off a Valmet m78, and I have some questions for anyone who might have experience with things like this since google search has not been helpful. Obviously this would be a pretty pricey project so I'd like to get it right the first time....

1) how are the barrels attached to the trunnion? I assumed they were pressed in like ordinary AK barrels, but I've heard rumours that some might be threaded? Also, is the rivet through the top of the trunnion acting as a barrel pin?

2) is there some obscure law against installing a restricted-length barrel on the Valmet, should I choose to do that, simply because it's an AK variant that is specifically named as exempt? Would that make it prohibited, or something ridiculous like that?

Thanks for the help, I kinda feel like I'm charting new territory here sometimes, but I know there's someone out there who is much smarter than I am with this stuff.....

 

[upnorth69]

1) how are the barrels attached to the trunnion? I assumed they were pressed in like ordinary AK barrels, but I've heard rumours that some might be threaded? Also, is the rivet through the top of the trunnion acting as a barrel pin?

Hi

No, barrel is threaded like all finnish made AK derivatives.

Being threaded, it means that (7,62x39 variant)
1) the gunsmith must first create the barrel
2) install it with the proper torque (200 to 250 Nm)
3) mill off the extractor relief with the barrel in the receiver (4mm to the left and 4mm to the bottom in respect with the center point of the chamber. Thickness to be removed is 0.8mm)
4) install the gas port assembly
5) make a jig to present the barrel at the correct angle
6) drill the gas port (4mm)

Good luck !

V

 

[Fuzzy Wool Hat]

Thanks a lot! This info really helps me

 

[upnorth69]

Happy to help

Just remember that for other calibers and barrel lengths, gas port diameter may be different (for ex on a 308w with 20" barrel hole should be only 1.8mm)

 

[KotKotofeich]

I'll just pipe up in here that it's possible to get keep it non-restricted but have the restricted AK look with a fake muzzle brake to go over the barrel.

That barrel is 18.5" long and set up to have the AK look forward of the handguard.

 

[Fuzzy Wool Hat]

That looks awesome! I was thinking something similar if I choose to keep it NR. Like a fake suppressor shroud or something similar to yours.

 

[Divermike]

Looks like a M71 gas block for a more AKish look.