TRIGGER LOWER LINK TEST RESULTS

[melloroadman]

I was able to get some chrony numbers in before my pump quite working so I only got about 60 shoots on the mod but I am happy with it . It is light and really has no creep its a keeper as far as I can tell so far. Thank you Crosman team A  for showing us the way . It does to the Discovery what the GTXIII does for the Gamo issue . I have a GTXIII in my storm and this mod is just about the same trigger fill as it . I say this so some of you have a comparison to go by. It is also as safe as a factory gun in that sear spring pressure and engagement have not been altered . My chrony numbers are consistent again . Which makes me happy and should help the 50 yard shooting I will try after I get a new pump from Crosman . Here are the numbers . Again same pellets CPH 10.5 FILLS 1900 - 1100 . I realize the new gun had slightly higher numers but that could be temperture related and the hammer was bone dry of lube and now it has some resistance do to lube. Marvin
NEW RIFLE
1   903
2   914
3   912
4   902
5   905
6   904
7   903
8   910
9   914
10  909
11  910
12  906
13  905
14  893
15  902
16  892
17  883
18  887
19  881
20  867
2 SCREW MOD
1   887
2   871
3   868
4   874
5   900
6   892
7   891
8   868
9   860
10  850
11  876
12  883
13  822
14  890
15  869
16  874
17  871
18  860
19  859
20  833
LOWER LINK MOD
1   848
2   870
3   854
4   867
5   865
6   864
7   871
8   867
9   869
10  876
11  876
12  872
13  874
14  860
15  860
16  856
17  857
18  856
19  850
20  846

[Splash]

Thanks Marvin, looks like I may be moving a pivot point myself.

[preez]

A nice picture write-up is due. Marvin?

P.S. Great work!!

[melloroadman]

Please read and if I need to take pictures I will . Just let me know. Marvin
http://www.network54.com/Forum/275684/message/1214268953/PICTURES

[melloroadman]

As always remember to be extra causes after any trigger mod and KEEP YOUR FINGER OFF THE TRIGGER UNTIL YOU ARE READY TO SHOOT the first few times until you become familiar with the pull again. Marvin

[fingerace]

Hey Marvin is the "two screw mod" that you performed this one?:  http://www.spiralsol.com/airgunmod/1005.pdf

Thanks

[melloroadman]

Yes it was .And no I was not happy. Also look closely at it and you will see that you are playing with sear engagement and pressure which can make a gun unsafe. The mod I did with the lower link is much easier and safer. It is not my idea if you follow my post . It is something Crosman did on their A TEAM F/T RIFLES . I just followed in their steps by reading other post . Stop and think about it . Its a leverage helper that's all. The first rifles produced did not have the three holes in the trigger case and the people before me had no alterative for a fix . Big Ed's has a adjustable sear on the market now that changes the leverage point with the sear for about $30. This lower link just changes the leverage on the lower link instead of the sear. With the adjustable sear some of the adjustment is still made by sear depth contact . The choice is yours but I will not do the screw mod again . Either the link or the sear is the way to go. If you do the link it cost you nothing but time and if you do not like it you can put it back to stock and order the sear.

[fingerace]

Thanks a lot Marvin. I will do the lower link mod according to your instructions in your post.

[preez]

It really transformed the trigger to a decent one. Being lazy, I did not grind the surface of the link or center punch it. Just drilled a tiny pilot hole first, and then enlarged with 1/8" (?) drill bit. Worked like a charm! I also did not replace the trigger blade spring, instead cut mine by one "loop".

Safety warnings!
1. Rifle could misfire or bump fire if the safety pin is not inserted back into the trigger group.
2. The safety will not work anymore in my rifle, even when engaged, it allows trigger blade to move enough to release the sear. This should be fixed easily by either grinding the trigger link or the lower link mating parts. That would increase trigger travel in the 1st stage.

I shot my disco today for the first time after installing few mods (HDD, trigger, muzzle break) and it is a completely different rifle. Can't wait to do accuracy testing!

Chris

[melloroadman]

Chris I am glade you are happy and yes it is important to keep the safety pin in the trigger group . If not there is not enough spring pressure applied to the sear . But I have not had any issues with my safety after doing this mod it works fine . Are you sure you have the sear spring engaged in the pin slot on the safety pin . If done as I described the only change in the link is the leverage point . The link and sear should be in their original locations and all other geometry the same. If the safety worked before it should work now. Marvin

[preez]

I don't really know why it wouldn't work anymore. I took it apart again and put it back together. Same thing. I ended up grinding a bit off the sear. It added more free travel to the trigger, but it's still good and now the safety works.

Chris

[4950cycle]

melloroadman - 6/23/2008 6:00 PM Please read and if I need to take pictures I will . Just let me know. Marvin http://www.network54.com/Forum/275684/message/1214268953/PICTURES

So what was the end result from this lower link trigger mod Marv  ?

[jeff124]

Marvin, If you have the gun apart in the future, a picture of the modification would be very much appreciated. And thanks again for the disco pats list. BTW I have posted some numbers on the "Yellow Disco Forum"
jeff124

[preez]

Since my rifle was apart anyway, I took pics of the mod. Second pic shows the trigger housing with 3 holes for link pin.

[melloroadman]

Chris thank you .Now if we could get a machinist to make a new lower link with the contact bar on the end of the lower link instead of where it is at and lengthen the back of the sear arm to add more leverage I think we would have a super trigger . But then again that is probably what Crosman is keeping under cover right now. Then again may be Mr. Tuna will read this and get to work on a new project. Marvin