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Old 01-07-2020, 03:38 PM
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Fastbolt Fastbolt is offline
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Originally Posted by armorer951 View Post
News to me. The ambi lever from the original OEM safety body on my 5906 fit the slot in the new decock only safety body just fine. I did configure a support on the back of the lever, if that's what you are referring to, but I'm not sure it was necessary. Seemed to work fine w/o the support.
When the decock-only assembly was first produced it was a LE-only option that required slide machining at the PC. The 9/.40's used the 9/.40 ambi levers and the .45's used the .45/10 ambi levers.

As production of the full-size TSW's was underway, they added the necessary machining to the slides at the regular factory during manufacturing.

By the time of my next armorer recert, they'd made a change in the armorer manual and class discussion of the decock-only option, telling armorers that when installing the decock-only on the 9/.40's they needed to order a .45 ambi lever.

The reason given was because they'd discovered the assembly might shift a bit left inside the slide in the 9/.40 slides, and if it shifted the wrong way the firing pin might hit against the inside of the assembly and potentially impede the pin and reduce impact force.

The .45 ambi levers had an extra bit of metal on the back that acted as a spacer, preventing the assembly from moving in the narrower 9/.40 slides.

Here's a pic of the 9/.40 levers (left) and the .45 lever (right). The pin punch points to the added material on the back of the .45 lever that acts as a spacer, limiting the lateral movement of the assembly inside the slide.

As soon as I got back from that class I checked my 3913, which used the decock-only assembly. I found that I could push the assembly left a bit.

I called one of the factory LE customer service guys and asked to order a .45 ambi lever & plunger, explaining the reason and what we'd just been told in the recert class. The guy hadn't heard of the change to use the .45 ambi lever in the 9./40 guns when using the decock-only assembly, but sent me one, along with the newer plunger. The older 9/.40 ambi levers used a semi-round headed plunger with a shoulder cut and a narrower head than the newer levers. The newer plungers were flat headed and cylindrical, and without the shoulder (for added strength). The wider plunger won't fit in the recess of the older levers, and trying to use the old plunger in the new levers makes for an improper, loose fit.

After the new lever and plunger arrived and were installed, I could no longer feel any lateral movement of the decock-only assembly in the slide.

Replacing the original manual safety assembly typically requires replacing the sear release lever, whether it's another manual safety assembly or the decock-only assembly. The reason is replacing the assembly usually changes the tolerances between the top of the sear release lever and the assembly body, which can change the decocking "timing". The sear release lever is typically fitted (filed) to put the decocking timing within proper spec for each particular gun with its manual safety or decock-only assembly.
Ret LE Firearms inst & armorer

Last edited by Fastbolt; 01-07-2020 at 04:37 PM. Reason: typos
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