1977 High Pressure Trigger Mod
Select Gate
READ GTA FORUM RULES BEFORE POSTING
GTA Forum Help Desk
GTA Announcement Gate
Dealer Area
GRIP
AirgunWeb Airgun Videos
Airgun Repository of Knowledge
Vendors and Vendor Videos
AirGun Expo 2021
Airgun Expo 2022
Contests and Giveaways!!!
Welcome New Members
In Memoriam
GTA Contributing Members
Shot Show Videos
Hajimoto Productions
Airgun Detectives
Air Gun Gate
BB Guns and Such
"Bob and Lloyds Workshop"
American/U.S. Air Gun Gates
European/Asian Air Gun Gates
PCP/CO2/HPA Air Gun Gates "The Darkside"
Air Archery
Vintage Air Gun Gate
Air Guns And Related Accessories Review Gates
Hunting Gate
Machine Shop Talk & AG Parts Machining
3D printing and files
Buyer's, Seller's & Trader's Comments
Bargain Gate
Back Room
Target Shooting Discussion Gate
Target Match Rules
Shooting Match Gates
Field Target Gates
The Long Range Club
100 Yard Match
Discussions By States
Welcome,
Guest
. Please
login
or
register
.
Did you miss your
activation email
?
1 Hour
1 Day
1 Week
1 Month
Forever
Login with username, password and session length
Home
About
Help
Old GTA
Gallery
Search
Stats
Login
Register
Advertise Here
GTA
»
All Springer/NP/PCP Air Gun Discussion General
»
American/U.S. Air Gun Gates
»
Daisy Gate
(Moderators:
GTA-Airgunner
,
Gertrude
) »
1977 High Pressure Trigger Mod
« previous
next »
Print
Pages: [
1
]
Go Down
Share This!
Author
Topic: 1977 High Pressure Trigger Mod (Read 154 times))
pblawler
Squirrel and Rabbit
Sharp Shooter
Posts: 632
Know where I hit'em by the sound of the whaap!
Real Name: Patrick
1977 High Pressure Trigger Mod
«
on:
December 09, 2022, 10:13:35 PM »
I have been modifying 1977s for more power for a couple years and the biggest headache with the 1977 is the terrible trigger pull and valve lock. I figured out a mod for the trigger pull that does not suffer from valve lock past 20 pumps reliably and used it for about a year now. It was originally documented here:
https://www.gatewaytoairguns.org/GTA/index.php?topic=197476.0
After several hundred shots the trigger pull dropped from just under three pounds to around one pound. The sear surfaces wore in and the required force to fire dropped. It was too sensitive and would fire while pumping without the safety on. The other issue I ran into was that the hammer spring was very strong and eventually compressed the sear/hammer fork such that the poppet travel was not sufficient for a full pressure dump. I fixed that issue with this mod:
https://www.gatewaytoairguns.org/GTA/index.php?topic=204072.0
The last issue to fix was the trigger sensitivity. My solution was to install a screw in the trigger guard that could be used as a trigger stop and spring seat, then drill and thread the trigger for a small screw to use as a spring seat. I didn't want to drill a factory trigger guard for metal receivers so I created a mold and cast some. Once I got a few new molded pieces I drilled and tapped one and started the prototyping. I installed a spring in the modified trigger guard and it worked really well. I can now pump the gun without it firing and the trigger pull is an easy two and a half pounds. I ditched the extension spring shown in the original mod because it is insufficient and a pain to install. These mods work really well. I will replace the screw in the trigger guard with a set screw and clean up a couple other things, at that point it should be a very reliable and accurate upgrade that will allow maximum power output from the 1977 with no valve lock and a sweet trigger pull. I use Rons trigger mod on my 880 and 822s, even with the 1977 piston valve lock is not an issue. On the 1977s pumping to 20 or more I use these mod.s. The trigger pull is still pretty long but that cannot be reduced too much with the springs in this mod because of the pressure. The sear surfaces are not hardened so it uses a significant amount of material interface to hold the hammer. I don't think it would be reliable or safe in the long term to reduce the sear interface length.
Logged
USA, AL, Falkville
Welcome to
thedaisybase.com
Print
Pages: [
1
]
Go Up
« previous
next »
GTA
»
All Springer/NP/PCP Air Gun Discussion General
»
American/U.S. Air Gun Gates
»
Daisy Gate
(Moderators:
GTA-Airgunner
,
Gertrude
) »
1977 High Pressure Trigger Mod