Reworked a few Remington 788 & 580 series triggers over the weekend

[JDHasty]

They make up into dandy triggers and don’t take much time or effort. There are at least three generations and the center fire and rimfire use a different safety lever and bolt stop, so unless you are familiar with the differences, keep the parts for each trigger together and separate from others.

We used to separate the trigger/sear spring and cut down the original and use it for a sear spring. If you want an adjustable pull weight drill and tap the front of the aluminum housing and use a light spring like out of a ball point pen. If you just want it lighter you can replace the combined spring with a lighter trigger spring of the right length. You have to put the trigger spring in from the trigger side and then put the trigger in and compress it before putting the trigger pivot pin back in. Both methods work very well. The latter method you may need to use the trial and error method to get the spring right. This is what the green and yellow figure show.

You now have a sear engagement screw. When you separated the springs using either method, you already did that. Both rest on the sear engagement screw, so it serves both purposes.

I’ll find some pictures I have collected up over the years and post them and you can see what I am talking about. Also when adding the adjustable trigger pull weight adjustment you have to take the bolt stop out to make adjustments. No big deal though. You will already have the stock off.

So, we didn’t do these that way. We moved the trigger pivot pin about .3 inches closer to the sear. To do this you need to have the sear engaged and scribe a line from the center of the trigger pivot pin to the sear. Then measure up from the pin and mark it, then use an automatic center punch on the housing.

I use a #29 and #32 CARBIDE drills and while making sure the sear is held in engagement (engaging the safety makes this easier) drill one side of the housing using the smaller drill and just mark the trigger where it will be drilled. Take the trigger out and drill the other side of the housing with the smaller drill. Then drill the trigger using the larger drill.

You can do all this with just a drill press, milling vise and machinists level. That is all there is to it. Move the trigger pivot pin to the new location when you put it back together. The one I installed in a 788 breaks at 2-1/8 lbs using the factory spring. If you want it lighter you can cut a coil or however many coils, but just make sure the spring still holds the sear a little past level.

You won’t know what it will break at until you try it because all triggers are unique to themselves, but it should be between 1-1/2 and 2-1/2 lbs with the pivot moved about .3 inches. If you want to end up with a 3-1/2 lb or so pull move it .2 or so, instead of .3 inches.

Using this method your pivot point is in a direct line from the original location to the sear so you will not change the geometry at all and you still have a heavy spring holding your trigger into the sear notch and not something like a spring out of a ball point pen. All you change is the mechanical advantage by moving the fulcrum.

Of course you do end up with a little more movement before the trigger breaks, but these triggers are really clean to begin with and I normally don’t bother adding a sear engagement adjustment. If you want to it is just a 6-48 hole drilled and tapped in the housing. A fifteen minute job.

[JDHasty]

This one has been drilled and the pivot pin moved. The second hole? That is so I can set them up at about 3.5 lbs for the kids. We did five this weekend and I don’t know how I may want to use them in the future, so I usually drill both holes while I have everything set up. This one is for a 580 series Remington. The 788 is the same. This one has a sear engagement inspection port, some do, some don’t. On most that don’t you can look in on the side the safety lever is mounted to and see it and scribe your line on that side. Either that or drill an inspection port.

Carbide drills are a must if you are moving the pivot point. You won’t touch the trigger with a HSS drill. All you will accomplish is to ruin the drill.

I use 6-48 screws instead of 6-32, probably because I have a bunch. They make the adjustment finer too.

If you are going to add a sear engagement/spring perch use a 10-32 for that. That sear spring is pretty tough and you need the stronger 10-32.

[Hal]

JD

Great write up.
It's always nice to have a good trigger.

Hal

[pertnear]

Originally Posted by Hal

JD

Great write up.
It's always nice to have a good trigger.

Hal

+1

I agree - Thanks JD!

Great write up & presentation. I admire anyone that can successfully work on triggers!

[JDHasty]

I'm glad that people could follow what I was saying. When I am working on them with someone trying to learn I have had others who have had a hard time following what I was saying.

Basically, there are multiple ways to improve these triggers for use where the factory trigger is too heavy.

As a general rule, they break clean and do not have a much creep. If you do come up with one that does have more creep than you would like, I usually prefer to go with a sear engagement adjustment at the location in the top figure. That way there is no chance of cutting away too much of the sear engagement. Since you already have the drill and tap out and are set up you might as well go ahead and put in an over travel adjustment screw at the same time.

I have pretty much settled on moving the pivot point and retaining the shared sear/sear-trigger engagement spring because I want that sear/trigger engagement spring pressure to be high. That way if the safety is off and the gun is bumped, dropped, whatever the trigger is still held in engagement by a pretty stiff force. With a lighter spring the sear is not as solidly held in engagement. But that does not mean that separating the sear spring and sear-trigger engagement springs is flakey. I just think I want that engagement pressure higher and then overcome the higher force by having a longer lever. That does come at a cost of increasing the arc the trigger moves through before the sear is released though. If you like the pull weight and there is too much creep adding a sear engagement adjustment screw is really easy to put in.

I use either a thin lock nut to lock the screws or will use a drop of primer sealer or fingernail polish. My buddy I was doing these with is going to set me up with an assortment of miniature nyloc set screws instead. I think that will actually turn out to be the preferred option.

Pro tip - never ship one of these barreled actions with the trigger installed. You will break off the stud that is just silbrazed to the receiver. Also be careful about having one sitting around the shop without a stock on it. If you do break off a stud, drill and tap the receiver and put a stud in it. Use a false bolt stop to align the trigger and using some soot or inletting black slide the stripped trigger housing down and file the stud to match the hole in the trigger housing until you get the housing seated. Drill a new pin hole and you are done. Then don't do that again.

[Bill K]

JD, could you list the books that the info and photos you refer too came from, maybe some would like to try and obtain some and gather and keep information regarding the diagrams and procedures to follow ? Thanks.