EncoHK....as you and others have stated, the pins supplied by RRA for their 2-state NM trigger are tight. I lubed them with Tetra Grease....and taped them in with brass drift pin. Also..I used a drift pin on the off-side, to act as a lineup guide. Pins are tight and will definately hold the new stuff in place.
Also...on my bushmaster lover, the bolt would drag on the hammer after round was fired (trigger held to rear). Bolt would recoil normally...but on forward movement into battery, it would drag on the RRA hammer.
I called RRA...talked to Steve (very helpful gent.) He relayed that some bushmaster lowers did cause this....he instructed me to slowly take off some of the upper hammer edge with a fine stone. He stressed slow removal of material.....stone and then try, etc.
It worked...I only had to remove a slight amount...really just polish up the edge. The bolt now will return to battery with no drag.
I do like the RRA NM trigger....it and my bushmaster do work well.
I also talked to a RRA parts dealer from the DFW area this past weekend. He relayed he has several reports from bushmaster owners having a similiar problem.
Also, there is a previous post on this board about the hammer/bolt interface.
Steve at RRA is a wealth of knowledge.
take care....