Author Topic: Going BACKWARD - polishing the PreB  (Read 274 times)

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Offline briang2ad

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Going BACKWARD - polishing the PreB
« on: January 21, 2019, 11:18:46 AM »
As per earlier, My PreB was giving me a little stacking toward the rear or the DA pull.  I suspected it was some grit in the frame and especially the place where the disco hots the frame.  SO I polished all that up.

DID a complete polish job on frame sear assembly, trigger bar and disco.  Reassembled and ...

Now it stacks BAD, right at the end of the DA pull. Feels totally smooth and light t that point, then a 12 LB break.

How is this possible?

Maybe when I stoned the frame on the right side (suspected burr), I took off too much.  It seems that maybe the trigger bar is binding on the LEFT side where the trigger bar slides under the frame ledge.  Possible?  When I just have the trigger bar in and put upward presssure on the trigger bar, it binds there.

Gun was shooting pretty well.  Now ruined.
« Last Edit: January 21, 2019, 11:47:27 AM by briang2ad »

Offline M1A4ME

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Re: Going BACKWARD - polishing the PreB
« Reply #1 on: January 21, 2019, 12:16:11 PM »
I'm into that shade tree mechanic stuff, myself.

Anyway, along those lines, do you have a spare trigger bar or disconnector you could install (one or the other) and see what the difference is?

Then, if you measure/feel a difference, measure the dimensions that you have a way of measuring and see if you can see where too much metal may have been removed.

Almost sounds like you've got enough clearance in there that once you get enough pressure on those parts one/both of them try to move (left/right/up/down??) and bind up on something else. 

Or maybe they deflect enough (not bending, but moving on the pins) that they almost don't move the sear enough to release the hammer and that extra effort is required to move the sear just that tiniest little amount more to let the hammer fly.  Almost like a trigger adjustment screw that's too far in and won't let the trigger come backwards quite far enough.  A normal trigger pull won't fire the pistol, but it you really crank down on the pressure it will go ahead and fire.
Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.

Offline briang2ad

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Re: Going BACKWARD - polishing the PreB
« Reply #2 on: January 21, 2019, 12:43:44 PM »
I may reassemble again (ugh) and try it out again, and order a new trigger bar and disco;  I can get the parts on Mil discount on CZ USA.  This is a major bummer,  It was ready to send out to get it Cerakoted.  I thought I'd try a little function check, and glad I did.

I reassembled the sear cage from rote - I could NOT have messed that up - right?  (SA was OK).  Checked against my 84 and its fine.

(Really dont want to rip apart my 84 to see how that hammer and trigger bar work in this one).
« Last Edit: January 21, 2019, 12:53:46 PM by briang2ad »

Offline Earl Keese

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Re: Going BACKWARD - polishing the PreB
« Reply #3 on: January 21, 2019, 12:54:43 PM »
Why not try some parts you have on hand first before ordering new ones?

Offline briang2ad

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Re: Going BACKWARD - polishing the PreB
« Reply #4 on: January 21, 2019, 01:12:46 PM »
Earl:

Was thinking that and then I just greased the rear of the TB, and carefully reassembled. All seems well now.  Not as smooth as my 84 or 94 Trans but not too bad.  I still have a little stack before the DA break, but it is a tad better than before polishing, and I'm not getting that weird effect last reassembly.  Can't figure this out.  I thought working on the disco, rear of TB, and bottom of the frame would do it all.  I might leave it alone and get it cerakoted.

IF I get time soon, I will swap the guts of my transitional out and throw them in the 88 and see what happens.  The Transitional (Avatar) had a terribly gritty trigger before polishing.  Now it shames a good revolver.

I DO think there is a hangup on the left side of the frame.  The TB rides underneath a guide in the  frame there.  When I have the sear cage out, and I put pressure on the left side of the trigger bar, I can make the TB bind as it engages this guide - keep in mind that this guide, because of the safety hole starts its engagement LATE.   I did some polishing there, but doubt I was able to remove enough steel to make a difference.  My BET is that if I stone the TB down enough on the horizontal extension, I can make this issue go away.  Not sure, but messing with a TB is cheaper than other options. 
« Last Edit: January 22, 2019, 07:47:15 AM by briang2ad »

 

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