Ruger MK II teardown and trigger job
finally found the Ruger MK II Target Stainless, I've been looking for...
came with a nice trigger at 2lb 8oz.
insides was really DIRTY, looked like bottom receiver had never been apart..... first up was a deep clean. taking apart was easy enough. found out quickly putting all the pieces back together was not so easy or straight forward.
did my usual deep cleaning using simple green, tooth brush and lots of water. put it all back together with tri-flow & moly on sear .... now trigger was over 3lbs and creepy. took it all back apart and clean off all lube.... re-assemble... now trigger went to slightly under 3lbs.
back apart it went .... then I stoned every part that rubbed against metal. including bolt, firing pin, trigger & linkage, inside of receiver, etc, etc.
then I took off sharp edges all over. polished sear surfaces to mirror at stock angles. put it all back together... finally got trigger back to the 2lb 8oz I started with.
bolt was really hard to cock... checked out main spring, which was binding badly. put a dab of moly grease, then worked grease inside by depressing spring with a pin punch. after a few minutes of working moly inside main spring. it smoothed out nicely.
put it all back together... bolt smoothed out along with rest of pistol.
could have stopped but really wanted a trigger under 2lbs.
next up was experimenting with the poorly designed trigger over-travel adjustment screw, provided on Target models.
I say badly designed because the only way to get at trigger adjustment is to take lower receiver almost entirely apart. then put it all back together... see if it works... take it apart...etc.. etc.
after spending an entire night taking it apart and back together... finally got trigger over-travel adjustment optimized. What a PITA to adjust!
the bad part was I was back to the 2lb 8oz.... the good part is... pistol was now working smooooth.... and I can take the Ruger down put it back together effortlessly.
Now I'm convinced the only way to change trigger pull is through changing sear angles. So back apart everything goes again.
after doing research on proper angles... carefully stone new sear angle on hammer and reassemble. purposely not including how to instructions on sear angles as everyone's skill level is different. most folks should take their Ruger MK II to a gun smith and/or install a trigger kit.
Success.... trigger is now 1lb 8 oz ... super smooth with zero creep.
tested sear for hold by slamming pistol HARD, several times at all different angles. No miss-fires... sear is holding solid. dead confident sear will not release until trigger is pulled.
here's a few pic's of Ruger MK II torn down for cleaning. was thinking of putting up additional detailed reassembly instructions past the excellent internal assembly instructions I used putting Ruger back together. http://www.1bad69.com/ruger/internals.htm
note pictures show trigger assembly still in receiver. found out in detailed instructions in above link, how to remove by depressing trigger pin locking spring.