[msg1956]

Hi All!

I am finally getting around to preping my ZB30 kit for a hopeful semi conversion! I had a question: The barrel latch seems to have no easy way to disengage it. It locks up tight, and I can't figure out how you are supposed to release it, short of sticking a screwdriver under it and prying back on the spring. Anyone got any ideas?

Thanks!

Jim

 

[sdk1968]

is your zb in 8mm??

 

[msg1956]

sdk1968

Yes it is. But all parts concerned are on the receiver itself, so the barrel is not an issue.

Thanks

Jim

 

[oprod]

zb

Is the latch hard to work or come out of position without the barrel? Mabey try some tool marking dye and look to see where it is binding. Mine (bren)needed a little overall length filing.

 

[bmg17a1]

Tight latch is related to the interrupted threads on barrel and in collar of latch. The threads on barrel and in collar have a slight pitch which assists in compressing the barrel into the barrel ring of the receiver when the latch is closed. The rotation of the collar moves it slightly back as it is closed, and compresses the shoulder of the barrel against the froknt of the receiver. If the timing of the threads is early the collar tightens up too early on the barrel threads making the latchup very tight, as the barrel is already seated against the receiver. The isn't very common with factory guns but does occasionally happen with mismatched barrels on the ZBs.
However, if your receiver is a reweld, and the torch cut went through the lockup section of the front of the receiver, it is possible the front section was welded a bit short. If this is the case, the collar is moved slightly to the rear, due to the front of the collar recess being a bit too far back. When the latch is closing it can't move the slight distance back since the shoulder of the barrel is already butting up against the receiver.
A remedy for this is to carefully, evenly surface grind the FRONT side of the collar removing a very slight amount of metal and then test. Removing some metal from the front side of the collar will allow the collar to move forward slightly which increases the forward/backward play in the threads when it roates around the barrel. With the barrel fully seated against the receiver the collar has more room to move the slight distance farward as it rotates and will need less force to close it before it tightens.

Bob Naess

 

[msg1956]

Oprod

Since the receiver is cut, and I need the barrel in place to hold everything together, I can't really tell how it works without a barrel in place. Thanks!

Bob

Thank you for taking the time to write your detailed reply. Just for the record, the receiver has yet to be welded up, it is still a parts kit. So, there is no pressure on the latch, as that area of the receiver is still in two pieces.

I guess my real question is, how are you supposed to release the barrel lock lever on a factory gun? The lever comes down, and the small, totally enclosed, spring loaded latch locks around the bottom of the receiver, and into the notch in the ejection port cover assembly.

My issue is not swinging the takedown lever up to unlock the barrel, it is getting the damned latch to release. I can see no way to easily unlock this spring loaded latch, and release the take down lever so it can swing up. It locks up solidly, and I can't figure out how you would change a hot barrel in combat!

Thanks again.

Jim

 

[Mongo]

The latch locking mechanisms variery with contract of the ZB series. I think I know of the latch you are using and the lock is very hard to get a finger on and I always wondered why they did not use the more easily to open latch. The only speculation I could have is the government that ordered this type of latch did not want the quick change barrel system to be used in the field other than thet I have no idea. You could get one of the other latch configurations and use it.

 

[msg1956]

Mongo

Thanks for the reply. I am glad it just was not me who thought the barrel latch spring was almost impossible to open! I have found very few pictures of the ZB30 on-line, and none really show the barrel latch details. The pictures I have found of ZB26s seem to show a barrel release lever with a much longer handle. That would appear to give you some leverage to overcome the handle latch spring.

By the way, love your web site. Wish I had the money for a Jap 99. My Dad was a Marine in the South Pacific, and it would be great to have a 96 or 99.

Does anyone know where I can find another style of ZB30 barrel release lever?

Thanks

Jim

 

[msg1956]

Guys

As long as I am asking questions, does anyone know if the lower receiver is interchangable between the ZB26 and ZB30?

Thanks!

Jim

 

[bmg17a1]

No they are not interchangeable. Very close, but they are slightly different and will not assemble and also swing up to lock with the crossbolt.

Bob

 

[msg1956]

Bob

Thanks for your reply. I am working on a semi conversion, and was wondering if I could use a $45 ZB26 lower from Omega vs butchering up my excellent ZB30. Do you think it is possible/practicle to do some work on the ZB26 lower to make it fit the ZB30? Since I don't know the differences, I don't know how difficult it would be.

If the ZB26 lower will fit into the ZB30 reciever, and the rear pin will line up, I can make that work. Since I need to make it so a FA lower won't fit the receiver, some mounting modifications need to be done.

Thanks again.

Jim