The thread title suggest that the most important aspect of an AR is reliability (to me it is) so I was wondering what kind of upgrades can you make that enhance the rifle as opposed to upgrades that you make that are questionable?
I will start with an adjustable gas block or an adjustable bolt carrier group. The benefit is that they make the gun shoot softer. To me that was never much of an issue because it is a .22 caliber bullet and even the roughest AR doesn't really kick. The negatives, you tune the gun to a specific ammo. If you change ammo you have to redial it in. It is another system or failure point for your rifle that is not present in the base design.
I will start with an adjustable gas block or an adjustable bolt carrier group. The benefit is that they make the gun shoot softer. To me that was never much of an issue because it is a .22 caliber bullet and even the roughest AR doesn't really kick. The negatives, you tune the gun to a specific ammo. If you change ammo you have to redial it in. It is another system or failure point for your rifle that is not present in the base design.