Username:

Password:

Author Topic: Gamo triggers.  (Read 163 times)

Offline Novagun

  • NZ Airgun
  • Hero Member
  • *
  • Posts: 851
  • Mana -1
    • View Profile
Gamo triggers.
« on: November 16, 2018, 03:44:57 PM »
Gamo triggers.

I got some assistance from blokes at the small bore club and the two stage trigger in the Gamo SAT trigger block works just as it should. With the two screws that lift the bottom lever adjusted correctly you can feel the first screw lift the lever and then a tiny bit of resistance as it reaches the end of its contact then the second screw makes contact to lift the lever so the sear releases the piston. The first stage is quite a firm pull and then the second just a light touch and off she goes. There is creap in the first stage and none in the second. You can feel the trigger much better with it mounted in the rifle than playing on the bench.

That was Mk1. Mk 2 has the first stage screw very close to the trigger pivot point. That will make the first stage heavier. I would like the feel when the trigger transitions  or rather where the first stage ends to be a bit more pronounced. That might happen when I try the Mk2 version. That is why I made it.
There may not be a Mk3 because I have used up the piece of scrap 6mm aluminium.

 Is the two stage trigger any better than a single stage?
No I don't think so.  The two stage can not be reset to stage one even with re cocking. When target shooting there is just another step in the shooting routine to carry out. It is no more accurate or should I say enables no more accuracy from the shooter. In fact the single stage is better for that.  It may even be better for hunting as long as the let off is not too light. The first stage may be safety feature for hunting. It does introduce one more component to the shot routine. I can do without that.

Making the triggers is not hard. Anyone could do it. You just need to mark it out and drill a series of holes near to but not touching the outline mark of the trigger. Cut out between the holes with an ordinary coping saw then file by hand down to the outline mark. It teaches you how to file square across the trigger.
Clean up and polish with ordinary aluminium oxide sand paper. Drill the pivot hole first because that gives you a datum point if you have used the original trigger as a pattern for the parts that need to fit the existing trigger block in case you want to check and remark the outline.

The holes for the adjustment screws are drilled through the trigger blade vertically, where you judge you want them and then taped to take three of four mm grub screws. Those holes need to be true to the tigger. Any run out is not good.

Of course if you had a mill and pattern you could turn out a few triggers quite quickly.

Pauly5 made a trigger by hand a while ago and even took some photos.

The difference between a single stage trigger and a two stage is that the single stage has only one adjustment screw and the two stage has two and they are in different positions in the trigger.

What I have found out is that there is more to triggers than what I know.

Anyway all this mucking about with triggers and barrel lengths and springs and gas rams has bought me to wonder about plastic stocks.  Another story there.
« Last Edit: November 17, 2018, 11:34:01 AM by Novagun »

Offline Novagun

  • NZ Airgun
  • Hero Member
  • *
  • Posts: 851
  • Mana -1
    • View Profile
Re: Gamo triggers.
« Reply #1 on: November 20, 2018, 08:30:22 AM »
Still playing around with the two stage triggers. The Mk1 version seems to have lost the very small demarkation pressure between first and second stage and I can't get it back with the adjusting screws. Without that pressure difference there is no point in having it. The slight feel when I thought it was acting as a two stage was so slight that I had to concentrate to feel it so not really much good.

The Mk2 is a bit hairy. Had a couple of accidental discharges. Downrange so that was ok but it is cause for concern.

I wonder if what I have is a two stage trigger at all. Maybe just a single stage trigger with two adjusting screws. I tend to think that is the case because both screws act on the same lever. One in front of the other.
However the way it operates is not dis- similar to the Weihrauch Record trigger, just not as good by a long shot.

I have had a look on Youtube but couldn't find anything of much help.

The Gamo CAT trigger on the advertising is a compleletely different construction and from looking at the video of the shot release, it looks to be just as bad as the SAT or maybe worse. Long creap.

I have enlarged a hole in the plastic side cover of the SAT trigger so that I can see the levers operating but doesn't make any difference.
Think I will park the project for a while. Just use the single stage, that works as it should.
« Last Edit: November 20, 2018, 08:55:03 AM by Novagun »

Offline Dvlnme

  • Sr. Member
  • ****
  • Posts: 361
  • Mana 4
    • View Profile
Re: Gamo triggers.
« Reply #2 on: November 20, 2018, 11:29:25 AM »
sounds like this is single stage trigger Hugh,one screw will change the sear engagment,the other just take
 up the slack and shorten the pull travel slightly,that being the case there only be a small amount of
 ajustment in the sear engagment before it becomes unsafe,personally i would leave the small amount of
 take up before it actually engages the sear  and releases etc.many i have dismantled have those two levers,
 why i dont exactly know,as both work together as a single unit when engaging the sear,and disengage at
 same time,proberly all you can do to improve this type trigger is polish all working surfaces and adjust the
 amount of sear engagement a little and possible fit an over travel screw.
 cheers mike

Offline Novagun

  • NZ Airgun
  • Hero Member
  • *
  • Posts: 851
  • Mana -1
    • View Profile
Re: Gamo triggers.
« Reply #3 on: November 21, 2018, 06:48:07 AM »
I had another play with the two stage trigger. This time I flattened the top of the first stage lifting screw. I worked well on the bench giving a reasonable demarkation between the two stages. It did not work so well under the pressure of the gas ram. The demarkation is there but not as good as the Record trigger or the Hatsan Quattro. However you look at it there is nothing wrong with a good single stage trigger.

You could argue that single stage is better because there is one less action in the shot cycle. Not a good arguement because the Record trigger is so good and the Quattro not too bad either.

This time it is really going on the shelf at least until the next rainy day.