Holy shit, you made it! This is the end all be all article discussing the best upgrade to your gun that will 100% improve accuracy! I have been to tons of courses and days at the range training and this is a sure fire upgrade. This works on pistols as well as rifles. Which is amazing because there are not too many things that work on almost any gun. So have you upgraded triggers, barrels, springs and more? So have I. I have been through so much that I know this will work for you. I have used this on my Glock's, AR-15's, AK's, hunting rifles and more. The cost of it is amazing as well. For as much as you get out of it, the cost is totally worth it.
So what is it? It's practice and training. That is the best upgrade you can do. You the shooter need to improve, get better. Are guns sometimes the issue? Sure they are. But most of the time it is the shooter. Time and again I hear people on Facebook bitching about their guns shooting this way or that way. They fail to look in the mirror and ask the hard questions. It is probably you! Do you hit the range regularly? Do you have a concealed carry permit? Are you doing your part? Most likely your gun is doing it's part, but the shooter is lazy and lacking in trigger time. Stop being lazy. Stop being weak. Own your trigger skills!