GP-100 action question

[444thumper]

I have smoothed up everything in my GP100 and it's all really good except for one little thing. Wanted to see if any of you could point me in the right direction as to what the cause might be. When I pull the trigger in double action mode, there is a "bump" just as the cylinder is starting to move. I thought it might be the pawl but if the cylinder is turned a little so it's not being moved, there is still the same "bump". My first guess is the double action cam but just wondering if some of you have had this same issue that you solved. I was following the Iowegan guide and tried to be careful to follow his instructions carefully. It had the same bump before I worked on it but was hoping I could get rid of it. Thanks for any suggestions you might have.

John

 

[GP100man]

Yep , be certain the pawl is`nt hanging in the window & check cyl. latch movement in the frame (the 1 in the bottom of the cyl window) sometime (rare) just as it starts to move it`ll catch on the boss the rigger pin sits in.

You`ll see witness marks on the boss with the hole in it (in the pic)

Akso smooth the surface of the cyl latch that the trigger plunger( arrow shaped ) peice mates with .

Check both spring & plunger holes for ruffness & free movement.

Inspect pawl & notches on the ejector for signs of binding ,preferably with 5x magnification for all inspections.


1 way to help is to remove the hammer & strut so the trigger action can be isolated .

I also recommend shimmin the trigger & hammer

http://www.rugerforum.com/phpBB/viewtopic.php?p=1362782#1362782

 

[444thumper]

Thanks for the great suggestions. I'll work thru all of them and report back.

 

[444thumper]

I finally found time to work on this. After checking out all the points mentioned, I finally found that it was the bottom of the hammer that was hitting the top of the bottom trigger extension, the part that picks up the double action sear. It was hitting just before it transferred from the hammer dog which was putting the bump in the pull that I was feeling. Thought I would pass it along in case anyone else runs into that situation. Had to use the pins to put the trigger and hammer together on the outside so I could see what was happening.

 

[GP100man]

Thanks for the follow up 444thumper !

 

[Carry_Up]

My advice in general is to have a close look at the areas mentioned in the GP100 book, but don't dive in with files and stones unless it is necessary. One GP I had the other day had a pawl return spring that was hanging up due to a burr inside that tiny hole. Another place to carefully observe is your hammer strut, which should be smooth on all sides and edges. Also, observe how the rear face of the top of the hammer strut rides in a small groove in the backstrap. Roughness in that groove or in the strut can cause a gritty feel right at the beginning of the trigger pull. The square opening in the strut retainer must also be smoothed on its inside faces - there is considerable force between the strut and the strut retainer during the operation of the hammer.

Another rough area has to do with how easily the ejector rod moves. After removing the ejector rod, have a close look inside its guide (forward most part of the crane.) Many are very rough. Take the high spots off, but don't open up the diameter. Keep in mind that smooth stainless steel parts often rub together producing a sticky feeling. That stickiness can get worse, the more shiny smooth you make the parts.


CU

 

[444thumper]

Thanks for the great advice from the voice of experience. I'm still getting my experience, often the hard way. I completely agree with what you said. I had gone thru a process of elimination, taking elements out to isolate the drag and carefully watching what was happening at the moment of the resistance. I have a hunch that I may have created some or all of my problem when I polished the hammer dog. Didn't think I had taken any dimensional metal off but could see how that could have created the issue. It was a learning experience for me. I'm going to file away your great suggestions for future reference.

John