Great piston setup option - Adams Arms Standard Picatinny Block Piston Kit

The Adams Arms kits are great for building piston rifles or for retrofitting to a piston setup. These aren't for the faint hearted though and do require some work to install them. If you're unsure about doing it, it's best to find someone who's competent to do it for you. These kits don't all come with the endcap that has the cutout for the piston either. Some of them do. However, you can make the cutout in a standard endcap with a dremel cutting wheel and some care. You use the bolt from your existing bolt carrier group and remove the gas rings from it which is quite easy to do. The main drawback of the kit is finding handguards to use with it. On Adams Arms website they have a list of those that are known to work. Others may be able to be made to work by modifing them. If you're planning on using the delta ring assembly then no problem. The piston fits fine under Magpul handguards (which is what I've used with them). The main advantage of the piston system is that the rifle wil run a lot cleaner since no gas comes back into the upper receiver.