I have a post ban Colt 6601 Match Target; Match H-BAR with a sear block. I use this rifle to shoot National Match Service Rifle competition. I am looking for advice on what to do with the lower. I want to replace the trigger group with a 2 stage and know that you can run into problems with the sear block. Does any one have any experience with machining out the sear block on these rifles? Does the entire block need to be milled out for a trigger group replacement? Will this leave 2 huge holes over my safety selector? My other thought was to replace the springs to get a lighter pull and try to polish the trigger sear. I like the idea of having a Colt Match Target lower and am trying to avoid replacing the lower (which I know is probally the easiets route)