4506-1 Trigger Question

[nickcarr]

So I picked up a "like-new" 4506-1 yesterday (SN# TYS922x) which I had transferred to my FFL. It was advertised as a short-term service weapon and then a safe queen. Well I'm not sure I would agree with the like-new status as the Novak sights are beat to hell. The paint on the rear dots has pretty much worn off. Anyway, I'm planning to replace them.

The pistol was incredibly dirty. I don't think I've ever seen a 3rd gen pistol this dirty before. I cleaned it pretty thoroughly without a complete teardown. I'm waiting to do that next weekend.

After a good cleaning the action is feeling 1000x smoother but I'm seeing an issue with the trigger. Like I said, I haven't tore this puppy down yet so I can probably figure this out myself -- but I might as well ask the experts to see if this is a known issue.

Problem: Trigger catches up on something after hammer is cocked

Repro Steps:

Empty magazine inserted. Cock the hammer fully. Slowly engage the trigger. At about the 25% mark, the trigger snags on something until I reach the zero-slack point before trigger break. There's an audible "click" as it hits the 25% mark.

Note:

If I remove the empty magazine from the pistol and try the above scenario I can still hear an audible 'click' immediately after pulling the trigger but the trigger doesn't hang up. With a magazine inserted, the symptoms are slightly more pronounced.

Theory: Problem with disconnector?

 

[nickcarr]

Update:

I removed the slide. What I'm seeing after cocking the hammer is that the trigger hooks are slightly away from the drawbar head. When I start to pull the trigger those trigger hooks 'engage' (the click) the drawbar head.

With the empty magazine inserted, I think it's just amplifying the noise of the trigger hook engagement. So it's not related.

 

[mscampbell2734]

OK, take a deep breath and relax.

VERY COMMON in Smith 3rd Gen autos. With the slide off look down at the top of the trigger. You should see a brass colored part riveted into the top of the trigger. That is actually a spring that keeps tension on the trigger so its in contact with the hooks at all times. Bend the vertical part FORWARD so it puts tension on the trigger.

What happens is during cleaning the spring gets bent and does not do its job. The result is what your experiencing, a sort of hitch/step in trigger pressure.

Other then the feel of the trigger action the spring has NO impact whatsoever on the trigger function. My department armour actually told me its common for armours to intentionally break the spring off so it does not break off on its own and cause issues down the road.

 

[nickcarr]

OK, take a deep breath and relax.

Why? Did I sound like I was out of breath?

You should see a brass colored part riveted into the top of the trigger. My department armorer said it's common to intentionally break the spring off...

Yeah I see it -- it's actually on the drawbar assembly. The brass spring is broken on the right side. The left side is still there but no where near the trigger hook.

 

[nickcarr]

Okay I'm pretty sure it's not the trigger play spring. The spring controls the 'play' of the trigger.

It looks like the drawbar head has a recessed area. At hammer rest the trigger hooks are engaged into this recessed area. Upon cocking the hammer, the trigger hooks slide up and lock in at the top of the drawbar head. When I engage the trigger, the hooks slip down back into this recessed area. This is what causes the slight hitch.

I guess I need to see if there's a way to remove that slack when going in to SA mode so that the trigger hooks are already engaged.

 

[armorer951]

That's what the trigger play spring does

 

[nickcarr]

That's what the trigger play spring does

Yeah thanks, I just figured this out. I was trying to do this manually. The trigger play spring forces the trigger hooks to stay engaged to the top of the drawbar head.

I only had one side left and after bending it over it removed the click.

Hmm, I guess I'll need to order a new trigger play spring and rivet.

 

[nickcarr]

Update

Thanks for the help guys. I ordered a new rivet and trigger play spring and it arrived last week. Removing the old rivet and replacing the trigger play spring was actually quite easy.

I just used two punches -- one with a pointed end and the other a flat end. Punched out the rivet with the pointed punch. Gave one tap with the pointed punch on the new rivet (which created a flange around the opening.) I then flattened the rivet with the second punch so that the spring was snug against the drawbar. It took all of about 10 minutes.

The new spring is perfect and works great.

Cheers!

 

[mscampbell2734]

Glad everything went well for you. Enjoy. I carried a 4506 for years as a duty gun when I walked footbeats in Watts. Got me through a few tight situations.