I have observed a lot of people asking how to make a 788 Remington trigger have a lighter trigger pull. I have heard the suggestion of putting a lighter spring in the mechanism. A weaker spring will have a small affect on the pull weight but not much. The main problem with this idea is if you get too light of a spring, it can weaken and not be able to push the sear up into full contact and a slight jar can set it off. Also a spring of too small of a OD can flex to one side and have the same effect.
A 788 Remington trigger and the 580-581-582 .22 cal triggers can have the same thing done. This also applies to the 591 &592 5mm mags. Here is how to make one of these triggers adjustable. First drill a hole in the back of the trigger housing 3/8 Inch above the bottom of the housing. This hole should be the proper size to tap with a 6-48 tap. Next drill a hole of the same size on the front of the housing 1/2 inch from the bottom of the trigger housing. These two holes need to be centered from side to side in the housing You are now ready to take a 6-48 tap and tap threads in the two holes that you drilled. You now are ready to put the trigger back on the rifle. Next you need two 6-48 screws. With the rifle cocked screw the screw in the back hole that you drilled. By tightening this screw you are now able to adjust the amount of sear contact. If you keep turning the screw the rifle will snap because you pushed the trigger out of contact with the sear. Now you can back the screw back and begin final adjustment. The hole in front is for a screw that adjusts trigger travel .If you run the screw in too far the rifle will not cock when you lift the bolt. Here is how to make the initial adjustment of the trigger. Back the over travel screw back so that is not making any contact. Cock the rifle by lifting the bolt then start turning the rear screw in . I will eventually snap the rifle then turn rear screw out a ways and re-cock the rifle. Now turn the front screw in until it stops turning because the screw is against the front of the trigger, now back this screw off and check the trigger and you should have a very nice trigger. You will have to experiment with how much sear contact you have by backing out and screwing in the back screw. If the trigger won't pull you have the front screw in too far. After I get my trigger adjusted I cut the heads off of the screws and leave just a little of the screw shank sticking out. I cut screwdriver slots in them at this point. After I had done a few of these I started epoxying a little piece of steel to the housing where I was going to drill the holes. This added thickness will give you the ability to cut more threads when you tap. The threads in the thin housing will hold with a good dose of locktite but, it is better to epoxy on the little pieces of steel. When you get the trigger adjusted to where you want it, give it a safety check. I always take a big rubber mallet, cock the rifle and give it a healthy whack or four on the but plate. I put lighter springs in but I know what I'm doing and if you don't you may have a unsafe situation. I also make my own springs and I know exactly how strong they are. I also at times do a little honing on the sear. This is usually not needed and is another issue of creating a unsafe situation.
I wanted to post a diagram of this modification and some pictures of one on a rifle but I'm 75 years old and I haven't gotten up the nerve to learn a new process. I do this on gunbroker and ebay but have not done it on any other sites. If you have questions or get hung up send me a email or give me a phone call and I will try to help you out. I came up with this idea many years ago and have done a lot of them. I don't think you are supposed to advertise on The forum but if you have no tools or mechanical ability I will rework one for you but not for free. I'm not looking for business, I shut my shop down years ago.
The dimensions pictured and the action pictured is a 591 Remington action the 788 is the same only larger. Notice that the over travel screw is not in this particular rifle. If I remember correctly this is the first one of these that I did. .You can lower the position of the over travel screw a little lower and the bolt release won't interfere with adjustment of the overtravel screw, just stay above the trigger pivot pin. Like I said this was the prototype.
David a. Cogburn