Parts

For .22LR, .22MAG, .17HMR, 9mm, and .223/5.56 NATO the most common thread pattern would be 1/2x28, with some exceptions for 9mm and .223/5.56 NATO firearms. As for .308/7.62mm and .338 Lapua Magnum, the thread pattern that is most commonly used is 5/8x24, with a few exceptions. Another typical thread pattern is 9/16x24 and it is mostly used for .40 S&W weapons.

Whichever you choose, you cannot go wrong. The single trigger is fast and simple to use; as soon as you apply a small amount of pressure, the firearm goes off. Two-stage trigger is extremely accurate and you know precisely when the shot is going to be fired. The first stage prepares you for the second one, when the trigger pushes the hammer up causing the firearm to discharge. So, it is up to you to make a choice.