FAS 6007 hammer group latch doesn't function

[lognom]

Hi,
I've been enjoying my FAS 6007 but decided to increase the 2nd stage trigger weight. Right after turning the screw only 1/8 a turn, the hammer "latch" stopped functioning. Consequently, cycling the bolt will push the hammer down, but the spring loaded latch located just behind the hammer won't move forward to secure the hammer in place. When I hold the hammer down with my thumb, I've tried pushing forward on the latch with a screwdriver but I can't get the latch to move. I tried turning the screw back to its original position, but no luck. Have anyone else here owned this pistol long enough to have had the same problem? I can send the hammer group to Chiappa for them to fix it, but for future reference I'd like to diy.

This gunweek article shows the hammer in yellow and the latch in orange. If you haven't seen the pistol, the hammer groups is sealed in metal. One cannot open up the housing to access the individual parts.

https://www.gunsweek.com/en/pistols/art ... ion-pistol

Thanks,
Lloyd

[David M]

If it is the same as the old FAS 607, you may have wound the sear screw in and locked up the sear bar.

[lognom]

David M,
Is there any way I can unlock the sear bar myself? I hardly turned the 2nd stage weight screw at all but that must've caused the problem because I didn't do anything else to the gun, and right before I turned the screw the hammer was latching properly.

[David M]

Which screw did you turn, upper or lower and which way did you rotate ?

[lognom]

I rotated the lower screw clockwise about 1/4th of a turn. My eventual goal was to increase the trigger weight to 2 1/2 lbs.

Btw, using the search function I pulled up this discussion which included a 607 hammer group diagram. My hammer group looks like that, and the part I described as a latch is the sear.

viewtopic.php?f=4&t=48724&p=245776&hili ... ar#p245776

Would loosening either screw unlock the sear?

Thanks

[JamesHH]

Crikey I did that drawing - thats for the 602, not sure if the 607 or 6007 are identical.
There was also a solid model.

Getting a stable trigger at 1,000g is hard enough, I wouldn't be attempting anything else.

I can't really think of a situation in which adjusting a screw would prevent the sear engaging as its always pushed forward by a spring, usually tightening a screw prevents the sear pulling back and the hammer going down at all.

Looking at the image the unit is completely different, the top screw is now in the sear, the lower screw controls the spring force on the sear, there is no 'latch' - so its now similar to a pardini.

I think you must have turned the top screw in, reducing the sear engagement to zero. Turn it out a1/4 turn and you should be OK.
It would appear tiny adjustments in the screw will give huge changes in sear engagement, good luck. Also remember euro pistols often have large engagement, they're not like revolvers with the sear hanging on a hair, pardinis usually have several mm for example.

To increase trigger weight you're better off adjusting the screw in the front of the trigger, at least to start with.

[lognom]

JamesHH,
It was definitely the lower screw I turned clockwise. However, after the sear froze up, I turned the lower screw back to it original position and turned the upper screw counter-clockwise, and it still didn't unlock the sear.

[Gwhite]

It's impossible to tell how the trigger adjustments function from the picture. Given that the 6007 is presumably a clone of the 607, you may be able to find more details on the adjustments & mechanics for one of those. Hopefully they copied those bits very closely.

Here's a bit more info from our host's files: http://www.pilkguns.com/tenp/spfas607.htm Unfortunately, it doesn't include much additional detail.

[JamesHH]

I can see how it works from the picture.

Not sure how it would have been borked by adjusting the lower screw, the only thing I can think of is the spring has jumped out of place or broken in which case it needs disassembly.

[lognom]

I wish I could disassemble the hammer group housing but it wasn't produced to allow the owner to do that.
Unfortunately, it looks like I'll have to send it to Chiappa.

Thanks.

[JamesHH]

This is the best I can find, the function of the two screws is clear.
Upper is sear engagement
Lower is sear spring force

FAS have done away with the intermediate latch so its now similar to a Pardini



Without seeing the unit its hard to know how to dismantle, 602s took a bit of brutality to open up but it could be done.

[David M]

OK, try a full reset.
Turn the lower screw (weight) anti clockwise two turns.
This will resuce the weight and ensure that the screw was not turned in too far to bind the long leg of the spring.
Turn the upper screw (sear) one turn anti clockwise, this will give the sear some engagement.
Cock the hammer. (If it does not cock something is very wrong, ginsmith may be needed.)
Very slowly turn the sear screw in (clockwise) until the hammer drops, this is the sear point.
Turn the sear screw back 1/8 turn (anticlockwise) to set sear engagement.
Now set trigger weight using both 1st and 2nd stage weights to 1000g total.

[lognom]

David,
Thanks for your advice but despite my doing what you recommended the sear still won't budge. I've contacted Chiappa.

[JamesHH]

Last thing I can think of is maybe some crud fell in here and is stopping the sear moving.

[lognom]

Using a magnifying glass and flashlight I can't see any debris.

After I talk with Chiappa, I'll report anything useful I find out.