I have a 5.7x28 ar pistol for sale possible trade it's the Cmmg radial delayed blowback barrel and bcg setup in an upper receiver with mlok handguard and flash can. It includes 2 Cmmg mags which fit in any ar lower and has an apf lower receiver that has been trimmed for a sig ambi bolt release. It makes a great little Pdw style setup and is super quiet with subsonic ammo. It's super light also maybe around 4lbs or so. It has a battle arms development safety that's an ambi setup but I only have the one lever you can grab another one for 10$ from battle arms and it has a flat trigger with a reduced spring set as well as ambi bolt release and extended mag release The barrel and bcg usually retail for around 460$ I'll take 650$ for the complete pistol and this lower will work with any upper receiver so if you wanna throw a 5.56 upper on it your good to go runs reliable with the 5.7 upper message for any question or more photos