How To Turn Your AR-15 Into A P90
This guide details the process of converting a standard AR-15 lower receiver into a 5.7x28mm firearm using the AR57 ULT upper receiver. The AR57 ULT allows the use of P90-style magazines and the 5.7x28mm cartridge, offering a unique shooting experience. The conversion is presented as a straightforward upper receiver swap, making it accessible for intermediate DIY enthusiasts.












