MPP Barrel measurement

Want's the length of the ESB rifle MPP tube, when measured from the Webley barrel to the end of the MPP tube

mines somwhere between 5 to 6 inches. i think its more around 6 though. i dont have a tape measure round at the moment to check.

I made a random guess, but I have a Home Depot chrome pipe in my scratch build,mine sticks out at 4 inches.

I ask cause years ago I bought a bunch of Heiland extensions for the inside guts, and found them recently, and can't bear to toss them . . but they're only four inches