Yes, this brake will work on AR15s chambered in .22 Caliber Cartridges (.204 Ruger, .223 Remington, 5.56 NATO, 22LR, 22Mag, 22 Hornet, .224 Valkyrie, etc.) with a thread of 1/2-28.
Yes this will fit on the Geissele Super Duty Rifle chambered in 5.56 NATO with a thread of 1/2-28.
Yes, this brake will work with the Springfield Hellion chambered in 5.56 NATO.
The Precision Armament Hypertap Muzzle Brakes, 5.56x45mm NATO will work on both those rifles.
The manufacturer states that the Precision Armament Hypertap Muzzle Brakes produce 84% reduction in recoil. A 7.5" AR Pistol in 5.56 has significant recoil for the cartridge due to the short barrel so this Precision Armament Hypertap Muzzle Brake will help reduce that recoil significantly.
These are the Slim Body Precision Armament Hypertap Muzzle Brakes.
It really depends if you CAN remove your muzzle device depending on the exact model you have.
Yes, As long as your barrel is threaded in 1/2x28, it should work.
No, this is not a suppressor adapter.
Yes, both the 5.56 and .224 rounds use a .224 diameter bullet. As long as your barrel is threaded in 1/2x28, it should work.