Small pin, big pin warning - CMC Triggers AR-15/AR-10 Match Grade 2-Stage Trigger Group

If you are building a standard AR/M4 with a lower manufactured after 2009. You need to order the small pin. Colt lowers before 2009 use large pin. Be sure you check the production year of your lower before ordering. I seen other comments that the trigger is loose. This is because they ordered the wrong trigger with the large pins because that's is for lowers with the larger pin holes. The standard AR/M4 hole is .154 which is small pin. Just a warning when ordering. Also if you are buying a 2 stage trigger you should know that if you're not building a duty rifle you don't need a trigger like this. An enhanced trigger is all you need for normal sporting use. The two stage trigger has two pulls. The first pull length breaks as a warning before you keep pulling to fire. This is helpful for landing precise shots and fire control. If you want to spend the money it's fine. But it's not necessary. It's a very good trigger though