Going FA with semi selected

[Spooder]

IMI FA Uzi Model B carbine. Original IMI frame, grip with "A" added, and Hebrew stamped bolt. "New style" disconnector (crescent shaped edge), new style trigger spring which reaches further forward and bends up, "old style" sear (which does not have the inward facing tabs at the inside of the end opposite the spring), and a stop dog. This setup works perfectly between FA and SA.

Got a grip assembly with Hebrew marks. Old style disconnector, old style sear, old style trigger spring with straight ends, spring retainer clip, and no stop dog. It works as expected off the gun.

Spare grip goes full auto in semi setting. It does not run away and stops if trigger released. Pulling the trigger with a slow squeeze, it drops the bolt, but does not release the sear at the same time (trigger has to move further back to release). Pull the trigger fast all the way back, it drops both and stays in semi mode. Looking at the two grips, the original has the sear ends sitting slightly higher.

Ordered a number of sears and disconectors, and will try different combinations to see if the timing changes to where it stays in semi regardless of slow trigger pull, otherwise, I'll have to send it in for a professional to tune it, if that is even possible. I'm starting to think this gun might only accept the original converted semi lower grip.

Was surprised that searching the internet did not find any mention of this issue.

 

[ScooterTrash]

Welcome to the Forum. You will find a bunch of great folks here. Keep in mind that there is nothing on an Uzi that Sam & Tina at Practical Solutions cant='t fix. First rate people. Might reach out to them.

 

[mike]

+1 For Sam and Tina

 

[sniperdoc]

If any gun is running correctly and stops doing so when you start swapping parts, put the original parts back in.
You'd be amazed how many times a gun (or even a car!) suddenly goes from "100% reliable" to "problem child" when perfectly good parts are replaced.

Put it back together with the parts you know worked; I'd be willing to say it will go back to working flawlessly

 

[Spooder]

It's back together in the original correctly functioning configuration. Just want to get the spare grip assembly to be interchangeable and operable.

 

[Spooder]

Talked to practical solutions, thanks for the suggestion. The timing is controlled by the gap between the selector lever "nose" and the disconnector. On the original grip there is almost no takeup when the trigger is pulled (before the bottom of the disconnector hits the selector nose, causing it to slide off the sear). There is a lot more gap on the second grip assembly.

Measured the two grips, distance from the floor to the trigger and sear pin holes identical. The two selectors are identical in height at the nose. It all boiled down to the disconnector, the "new style" has significantly less takeup. So I've ordered another new style trigger/disconnector assembly.

 

[MGMAN45]

IMI FA Uzi Model B carbine. Original IMI frame, grip with "A" added, and Hebrew stamped bolt. "New style" disconnector (crescent shaped edge), new style trigger spring which reaches further forward and bends up, "old style" sear (which does not have the inward facing tabs at the inside of the end opposite the spring), and a stop dog. This setup works perfectly between FA and SA.

Got a grip assembly with Hebrew marks. Old style disconnector, old style sear, old style trigger spring with straight ends, spring retainer clip, and no stop dog. It works as expected off the gun.

Spare grip goes full auto in semi setting. It does not run away and stops if trigger released. Pulling the trigger with a slow squeeze, it drops the bolt, but does not release the sear at the same time (trigger has to move further back to release). Pull the trigger fast all the way back, it drops both and stays in semi mode. Looking at the two grips, the original has the sear ends sitting slightly higher.

Ordered a number of sears and disconectors, and will try different combinations to see if the timing changes to where it stays in semi regardless of slow trigger pull, otherwise, I'll have to send it in for a professional to tune it, if that is even possible. I'm starting to think this gun might only accept the original converted semi lower grip.

Was surprised that searching the internet did not find any mention of this issue.[/QUO

 

[MGMAN45]

Open up the slots in your receiver where the sear protrudes SMG sear in Hebrew grip will not work unless you enlarge the slots in your receiver.Use the Hebrew marked grip.No stop dog needed.Enlarge your sear openings in your receiver.Good Luck.

 

[BWE Firearms]

You are going to have problems if you start mixing new style and old style fire control parts. Stick with one or the other.

 

[Spooder]

You are going to have problems if you start mixing new style and old style fire control parts. Stick with one or the other.

Agreed, the old style didn't work so I am upgrading my spare grip to the new style. I sent BWE an order for the new style trigger/interrupter and trigger spring.

 

[BWE Firearms]

You will also have to replace the sear with the new style.

 

[rabid]

You will also have to replace the sear with the new style.

Just curious, are there any photos of the "old" vs "new" FCG parts in the reference library (or elsewhere)? I've looked but I didn't see any photos of the FCG labeled as such.

I'd like to order some spares, but I didn't realize there were two variants until this thread, so I want to make sure they will work together.