Help me with a question...

[gspn]

Today I tried to perform a trigger job on my Crosman TR77 NPS. Long story short…it went wrong. I took too much stuff off the trigger and spent several hours with no schematics trying to figure out how it should all go back together.

I got the pieces back together…(not sure it's correctly assembled)…but now…the gun won't cock. It's a break barrel design. I can break the barrel open and there's pressure, but it won't lock open to where I can load a pellet…it just springs right back with full pressure. Any ideas on what I screwed up?

Anyone have a schematic of the trigger assembly? The owners manual has nothing.

 

[Mousegun]

You may have seen this before but if not, it may help.

http://www.gatewaytoairguns.org/GTA/Parts_Schematics/CROSMAN,_GAMO,CHINESE_TRIGGER.pdf

Another thing you may try, assuming you got everything back in place properly, is turning the adjustment screws to see if what you did pulled the adjustments out of range and all that may be needed is a tweak on the screw or screws to get back in so that the sear grabs what it is supposed to.

 

[gspn]

THANK YOU!!!!!!!!!!!!!!!

Last night was about three hours of trial and error trying to get parts back together. The trigger parts basically came apart like a claymore...parts went everywhere before I could see where they came from...so I didn't have much hope of putting Humpty Dumpty back together again.

Armed with your pics I have renewed hope that I can get the gun back in action. I was ready to throw it in the trash last night.

 

[Chevota]

How did the trigger job go? Success? If not I have info for doing a trigger job on that trigger, several different options from a basic 30 second fix to making it like a gold aftermarket or better.

 

[gspn]

Still struggling. The instructions I got from Mousegun are awesome…but they are pictured from the perspective of the trigger pack being off the gun and re-built from the bottom up. I can't get my trigger pack off the gun…so I'm trying to have to figure it out in reverse.

I'm a mechanical guy…I work on my truck and car and bike all the time…but this trigger pack has me confounded. I have no idea what I'm doing.

 

[gspn]

Now I have all the trigger pieces back together…but the gun won't function.

The safety seems to work, the trigger seems to have a normal range of travel…but I can't cock the gun and therefore it won't fire.

Normally when I cock it there's a lots of pressure, then it "snaps" into the open position for loading.

Now when I cock it there's some pressure (nothing like normal) and the gun won't "snap" into the open position for loading…there's just constant tension and if I let go of the barrel it will return automatically to it's closed position.

I have no idea what to do. Might have just ruined my first air gun with a "10 minute" trigger job that's consumed 7 hours over two days.

 

[Chevota]

It's not ruined, probably just a spring in the wrong place or something. I noticed in that guide it showed a sear upside down in one pix, that would do it too.

write me at chevota at hotmail and I'll send you some pix that help

btw, you have to take the gun apart to get the trigger housing out, meaning puling the main crosspin and releasing the spring. A Crosman nitro needs about 170lbs or so to take the pressure off the spring to remove or reinstall the pin. I can do it in seconds with no tools, but if it's your first time it can be hard to get apart, and extremely difficult to get it back together.
You can do a trigger job without taking the trigger housing out, but imo it's much easier to work on when it's out.
Also imo the gun should be given a new main seal while apart, and fixed so it won't tear up the new one like the original is.

 

[mattfinley]

I realize that this is an old thread, but I was wondering if you ever got your rifle fixed.. Like an idiot, I took out my safety pin instead of the trigger pin and then had to figure out how to put it back together after the spring pinged out across the room. Then I finally got the trigger out to do the "10 minute washer mod" and screwed it up nicely.
.
So tried to put it back together with those schematic pics I saw in another site but now get the same deal with one difference. If I try to cock the barrel 4,5,6, times and fiddle with the trigger while I am doing so, sometimes it will "catch" and cock the rifle to hold so it can be fired...
.
So I am in the same boat as you and am hoping you found out the mystery behind yours.

Thanks.
Matt

 

[Chevota]

It's probably this spring here which people often have trouble with.
Without that spring trying to rotate the sear clockwise as viewed in the pix, the sear will only catch randomly. So first remove the trigger, adj screw and its plastic nut. Now pull the pin holding this sear so you can get the spring into position like shown in the pix. Now try to insert that into the trigger housing and get the pin thru it, which is done with the long tail end of the sear and springs tail pointing down so there's no spring tension fighting you. Once the pin is in you then swing the sear so it's back inside the housing and you should have a lot of resistance from the spring. When you do this is normally works, but that spring stops on the pin for the other sear which has a torsion spring wrapped around it. As long as that other sear moves freely you should be good to go, but I prefer to push that upper torsion spring to the side so your spring fits next to it rather than between it. Should make sense when you look at it.
Once everything looks good you can rotate the sear up into the trigger housing and once far enough in you can re-insert the plastic nut to hold it in place. The rest is easy.
To get the plastic nut out you have to remove the big square head bolt behind the trigger, but you really have no choice other than cutting the plastic nut and discarding the adj assy.
Hope this helps..

 

[jcwit]

This is one of the reasons I refuse to dissemble certain products. There isn't many but there are some.

Another is a Remington Nylon 66!

Heck I've even done a Corvette from frame up, restore, myself & brother, but there are limits.

 

[gspn]

I did get it back together again...and Chevota is the only reason it happened. That guy knows more about air guns than anyone I've ever met or heard about.

I think he might actually be one of those Artificial Intelligence computers...like the one that can beat anyone in chess...except his thing is guns.

It sounds like he has you on the right track. I wish I could help but it was a long time ago and as a defense mechanism, my brain has blocked a lot of those memories.

 

[jcwit]

I'll second that, I've read his reviews regarding products on air guns and air guns themselves. Very knowledgeable fellow.

 

[Chevota]

Thanks for the kind words Glad to be of help too. I hate to think people are stuck with a problem when I have the answer, and hopefully people pay it and all free help fwd.
The guns are really quite simple but I guess few are interested in the details. People just want them to work which I can relate to. Like most could care less how their car works, they only care that it does!