When I build or assemble a rifle, I like to do it right. Nothing bugs me more than having to rig something or accept substandard performance out of a weapon because a certain accessory only partially accomplishes a purpose. This can be especially true when you are suppressing an AR-15. Suppressors are really starting to take off in popularity these days as more and more civilian shooters are willing to navigate the red tape that comes with enjoying the benefit of these tools.
The best, and most expensive, route to suppressor success with an AR-15 is to buy a rifle (or complete upper receiver) from a high end manufacturer that builds it from the ground up with a adjustable gas block (switch block). Aftermarket adjustable gas blocks of varying quality are available but may be difficult to fit or install. Also, most are of the less robust “clam shell” design (versus a pinned gas block) that only uses screws to tension the device around the barrel. Running a suppressed gun “wide open” (without an adjustable gas block) is certainly an option, but be prepared for the extra wear and tear and filth that comes with being over gassed.
Innovative Arms is now offering an adjustable (stripped) upper receiver for direct impingement AR-15’s through Palmetto State Armory. This eliminates the need for a switch block and allows proper function of the rifle in suppressed/unsuppressed mode by simply toggling a switch built into the upper receiver. Any AR-15 owner with a vise, block, and armorer’s wrench can theoretically simply swap upper receivers and have a no-compromise rifle that is suppressor ready. Other benefits include the ability to switch settings without risking burning your fingers and slowing the cyclic rate by about 100 rounds per minute. It is certainly an interesting development if it lives up to its manufacturer’s claims.