# Remington 597 Sear Spring/Stop Idea



## GrouseHiker (Mar 3, 2010)

I originally had had an idea about using a carburetor mixture screw as a sear stop. I'm sure I had seen (while messing around with various engines) something that might work, but I couldn't locate the part. Then, I rediscovered McMaster Carr (which I'm positive I knew in a previous life), and possibilities started to appear. Here's my take on the sear spring adjuster and sear stop.

I had never considered the possibility of adjustable sear pressure, and I found the sear stop (rather than the trigger overtravel stop) to be an "elegant" solution for this rifle. Here are the basic parts from McMaster (including a shorter version of the sear spring adjuster).






The basic concept is concentric set screws. One for the sear spring, and a smaller one to serve at the sear stop. Thanks to McMaster, I discovered "vented" set screws. In my mind, the "vent" looked an awful lot like a pilot hole:





It turns out the "vent" WAS a pilot hole. Through various mental gyrations, I selected a 3-48 set screw for the sear stop. That was based on a 3/32 (0.09375) drill bit passing easily through the factory sear spring (which I didn't see any reason to swap out):





Once all the stuff came in from McMaster, I went to work drilling and tapping the sear spring set screw. Luckily, the set screw came in stainless steel, which didn't have to be annealed to soften. Tapping to 3-48 is seen here with a bottoming tap. I tapped from the point of the set screw and stopped when the tap got the the larger hex socket. I didn't want the sear stop to encroach on the hex socket of the spring adjusting screw:





I had originally intended to install a threaded sleeve to avoid having the sear spring set screw in plastic; however, my test installation has worked pretty well without the sleeve (knurled sleeve pictured in the first photo above). Here it is installed:





I was originally concerned about the sear spring hanging on the threads of the sear stop, and I did stone the threads down a bit. The first installation had the sear stop too far aft. This was probably due to inaccurate drilling. I modified the hole, and got the sear stop and spring positioned closer to the center of the original sear spring seat.  Here's the installed assembly with the sear spring in place. This is the position of the sear stop after assembly and testing:





A cool feature of this mod is the ability to adjust both the sear spring pressure and the position of the sear stop. Here's the hex wrench in place for adjusting the sear stop:





Another good feature is the sear spring is captive - it can't pop out since the sear stop runs through it (it can fall out if the sear is removed). I had previously installed an oversized pivot pin for the trigger, and the feel of the trigger is excellent now that the trigger travel is controlled.


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