Surefire MB556K vs MB556K-PN

[Toddler]

Looking for someone who has shot both. I know they look about the same but the ports on the PN version are smaller. I was just wondering if the PN performs as well as the other, or if it's better to drill the regular version for pinning. Then again I could wait for a SFMB 556.

[fallenromeo]

I have not shot the PN version. However, (and someone feel free to correct me if I am wrong) I believe the PN version is exactly the same. The only difference being it is slightly longer for ease of pinning to become permanently attached.

[Toddler]

I originally thought that the PN version was a MB556K with an added shoulder, the regular version and the PN are exactly the same length. The body of the PN is a shrunken MB556K with a shoulder added for pinning. The ports in the PN version are smaller than the other. There is a youtube video that shows this.

[fallenromeo]

I guess I had incorrect info then. I could swear I read on here somewhere that the only difference was for the pinning. cheerfully withdrawn, now I am in to see what someone says about the differences too because I am interested to know.

[Stickman]

I have used both and not felt a difference. However, it was not back to back firing of weapons on the same day, and same ammo.

[aftermath686]

The MB556K-PN is primarily intended to be used for permanent attaching. It does also have neutral porting, as opposed to the original MB556K.

The new SFMB-556-1/2-28 (new SF SOCOM series Muzzle Brake) will also be neutrally ported on top, however it has pilot holes at the 3 & 9 o'clock, with the 9 o'clock hole being pre-drilled. The user can choose to drill through the other side to tune the brake if he so chooses.

The new SOCOM adapters (muzzle brakes) in 7.62 and 6.8 will be neutrally ported on top with pilot holes on both sides so the user can tune if he chooses.

The neutral porting was decided on the larger caliber brakes because they are more commonly used for precision, and the neutral porting loads the bi-pod on precision guns evenly. The older brakes that were non-neutrally ported tended to cause a gun to rock one bi-pod leg up slightly...

[Robb Jensen]

I've fired both side by side and couldn't feel any difference.

[hjmpanzr]

I've fired both side by side and couldn't feel any difference.

Same experience (last Friday). No discernible difference.