788 trigger mod: where to source springs/ set screw length

cody c

cody c

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788 trigger mod

Hey all, as per the above image pilfered from the web I'd like to modify my 788 trigger. I'm curious if anyone has any reccomendations as to where to source a kit or set of small compression springs, or are gunsmiths robbing things like pen's for their springs or hair clips from their wives or daughters or something more often than they'd like to admit?

Also if anyone happens to know what length set screws, I could order a kit or longer than needed and cut down, but I'd rather get a proper length with a tip to keep a spring centered or the nylon tip for sear engagement or overtravel

Thanks!
 
That drawing is pretty close to the way it should be done. When I was doing these conversions, I just used 6x48 screws since I had many on hand. Springs were clipped from spring stock I always had.
 
Leeper said:
That drawing is pretty close to the way it should be done. When I was doing these conversions, I just used 6x48 screws since I had many on hand. Springs were clipped from spring stock I always had.
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Did you use a nut on the 6x48 screws as well to tighten them down, or just loctite? I'm guessing you may have just cut the screws down to length?
 
I just set the trigger then staked the screws in place or used perma tex. I was doing these around 1978.
 
6 x 32 has no place on a firearm... use 6x48, it's readily available and has finer adjustment. If you are good with the tapping you can leave the 'bottom' of the hole a little tight. Blue Loctite works well too.

An option for a better trigger is simply to polish the sears, remove a bit of the engagement and replace or shorten the sear spring.
 
guntech said:
6 x 32 has no place on a firearm... use 6x48, it's readily available and has finer adjustment. If you are good with the tapping you can leave the 'bottom' of the hole a little tight. Blue Loctite works well too.

An option for a better trigger is simply to polish the sears, remove a bit of the engagement and replace or shorten the sear spring.
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I know that you've been on the tools for a long time Dennis, your wisdom is appreciated.

I ordered a few of these yesterday, and some 4mm nuts, I'm not sure about the spring rate, they may or may not be appropriate but I thought I'd take a look. These won't be as fine threaded as the 6-48 screw, so maybe they wont be ideal.



I believe the term would be a "spring plunger set screw", for the above diagram, the added trigger spring doesnt need a lot of travel and there is a fair bit of leverage from the trigger to spring relative to the pivot point. And at least with this spring plunger, the spring is trapped and shouldnt eject and get lost, I just hope it's consistent and has an appropriate compression weight.
 
The reason for the use of 6x48 was, as Dennis stated, because gunsmiths always have a bunch of them as well as taps for that thread. I kind of like the spring plunger set screw idea. I'm assuming you plan on doing five triggers since you will only need one per trigger. If the spring rate is too high, locate the weight of pull screw at the position shown for the overtravel adjustment in your picture (this is where it should be anyway). Also, move the sear engagement adjustment up so the sear spring sits on the screw rather than the trigger. This way, the sear spring has no effect on trigger pull. If the spring behind the plunger is too light, you might have to move the screw to the higher position or use a heavier spring.
 
Thanks mr leeper, as for 5 triggers, only plan on doing one, it's just a minimum order quantity, I'm also ordering a bunch of set screws, if it works I may post something in the EE and put some screws and nuts in a bag and sell for $5 or something to lessen the cost to me.

I agree as to your comment on spring rate and plunger location, I guess I'll have to measure its compression weight, and evaluate based on fulcrum points in contrast. And yes I get what your saying about the set screw taking the spring off the trigger and only pressing on the sear. In the verbage for the trigger mod it mentions only putting enough pressure on the sear to allow it to reset (by cutting it down in length)

As a side note, the trigger is a small piece of a much bigger project. My work involves the use of autoCAD for industrial (whats left of the oil and gas industry) electrical design, in my spare time at the office I've scratched up dimensions for the trigger in CAD, as well as the action and floor plate (flimsy little thing). My project is to create a design to move the trigger forward, shortening overall length by over an inch on an already short rifle (rear bolt lugs). This is purely for design fun (distraction) for a personal project

Basically I'm planning on getting some triggers waterjet cut (steel), and bottom metal cut (aluminum). The reason for the trigger is I want to move the trigger forward, as well as the trigger guard, so that the trigger guard overlaps the magazine and has it's release inside the guard. You can see this layout/idea below in the image of a pdf.

Working on a bedding block file now. Some pictures of what I've been playing with. I have a friend who works with solid works and CNC mills and lathes, he's offered to help me simplify the bedding block sometime for simplicity of machining ($) hopefully we find time for that in the near future.

If you have any design feedback, feel free to share your comments or criticism




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[url=https://flic.kr/p/ZLGz9s]layout1 by [url=https://www.flickr.com/photos/157971454@N02/
 
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A worthwhile project. However I'm pretty sure that I have a 600 trigger That is already moved forward and I think that it will fit the 788 if my memory still serves me. I can see you wanting to do this on your own.
Neil
 
dan belisle said:
I've done a half dozen or so 788 triggers like this. Worked out well on all of them, knock on wood. - dan
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Good to know, they seem to have a short pull on them, almost no trigger creep, though the pull weight is a bit more than ideal.

I found my left hand .308 just a while ago, I haven't shot it yet, but plan to rebarrel, restock and modify it a lot obviously. They are neat little rifle, the bolt feels sloppy kind of like an enfield does, well not quite that sloppy, and with the rear bolt lugs and 60 degree lift the range of motion to cycle the bolt feels more like a lakefield .22 than a long action 700.
 
zuke said:
Is anyone still doing this upgrade?
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Which upgrade? Or do you mean is there a gunsmith who will do the trigger mod? probably guntech or leeper could help you out with the trigger mod, and any good gunsmith should be able to figure it out equipped with the picture at the top.
 
I ordered the bottom metal, guard and triggers to move things forward (everything but the bedding block) to be cut by waterjet, the minimum order was 6 of them for about $300 and requires some work to assemble still.

I'll post some pictures when that much is assembled, this will require a one off stock which is part of my project. If anyone is interested in one of the other 5 sets to do a similar project feel free to PM me, but I'd like to show some assembly pics so you know what your getting into, I may update this thread or start another.

The bedding block may be an option later, as the 788 is somewhat uncommon i doubt there is enough interest in this forum though but if anyone is interested...
 
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