Yes single crack open. I ordered the Bellm spring kit for it and tried to do the install myself. Can't figure out how to put it back together. The interlock and sear mechanisms are tough and I have no idea how to put the spring with those. Lol I need help
Also I actually have the armorers manual from helms on that trigger upgrade, forgot to tell you other day in PM's I was half asleep. Just let me know if your other place doesn't pan out.