October 7th, 2010, 02:47 PM
Join Date: Aug 2010
SAI M25 Trigger Group Install Report
I just picked up an M25 trigger group from a forum member and had a chance to play with it today. Its adjustable as advertised from a little under 2 lbs to a little over 4.75 lbs with a smooth 1st stage and a very crisp let off with no creep. The adjuster seems to work by varying the pre-load on the rear of the trigger - the more pre-load applied the higher the trigger pull and vice versa. The sear on the trigger appears to be one from an M1 Garand.
Before I put it in my rifle I decided to lube it up since it was brand new and bone dry. SAI warns you not to take this thing apart in the instructions and now I see why. It does not come apart like a regular trigger group nor can you put it back together the same way as a standard one because the adjustment block gets in the way and the hammer spring/plunger housing is modified. Normally you first take out the trigger pin and then remove the trigger/sear and then the hammer spring plunger assembly , etc. With this unit you must first remove the adjuster screw and nut, then the trigger pin and then the hammer pin. You then have to pull the trigger/sear assembly up and over the adjuster block. You then take everything else apart normally. However you need to watch out for the adjuster spring under the adjuster screw and the adjustment plunger that sits inside the adjuster block.
To put the thing back together you have to first fully compress the hammer spring assembly and hold it fully compressed with a plastic wire tie. Otherwise you cannot put the thing back together. Once hammer spring assembly, the trigger and hammer pins are back in you snip the tie and remove it. [Note : the disassembly/assembly procedure described above is for information purposes only. If you follow them you do so at your own risk]
To put it in my rifle I had to remove about 1/8" of wood at the rear of the trigger housing hole in the stock to clear the adjuster nut/block. I also had to remove a few burrs from the trigger housing so it would easily slide into the receiver and a small amount of bedding material so I could latch the trigger group into the rifle. Until I removed some of the trigger group bedding there was no way a mortal could latch that trigger group in place!
Once the rifle was back together I measured the trigger pull. I came out right where I adjusted it - 3.5 lbs and passed all the safety tests.. Can't wait to try it out tomorrow.
Last edited by RGPM1A; October 7th, 2010 at 02:53 PM.
Reason: clarify post