Integrally suppressed rifles build the suppressor straight into the barrel, rather than turn it into an attachment placed on the end of the muzzle. The obvious downside to an integrally suppressed rifle is the suppressor can only go on one rifle. However, building the suppressor into the barrel allows for a shorter overall length, lighter rifle, and (usually) better sound suppression.
Witt Machine already makes some excellent integrally suppressed AR-15 upper receivers in .300 Blackout and .223/5.56. Now they are adding an integrally suppressed Ruger Precision Rifle to their offerings.
Unfortunately, integrally suppressed rifles still require the NFA $200 tax stamp and waiting period.