need help to choose which inner barrel assembly

[leblanc74]

I am about to purchase this
G&P Steel Outer Barrel for Western Arms M4....Length: 350mm / 13.5"

now I wonder which inner barrel suits best:

G&P 6.08mm Inner Barrel with Hop Up Chamber Set for Western Arms (WA) M4 GBB (C) (370mm)

or

G&P 6.08mm Inner Barrel with Hop Up Chamber Set for Western Arms (WA) M4 GBB (B) (325mm)


I want the inner barrel to align perfectly with the outer barrel;however, both inner barrel sets has 20 to 25 plus or minus MM each, am I missing something here?!?

[leblanc74]

I figure that the hopup chamber assembly will compensate the differences?...Am I right?

[L473ncy]

I have a 500mm inner barrel on an 18" outer. 500mm is actually something more like 19.7". Knowing that, my inner barrel does stick out of the outer by a little bit but it is still covered by the flash hider.

If I went with a 469mm inner it would have been more flush against the end of the outer barrel; that is 18" is about 457mm and the extra ~12mm is taken up by the barrel inside the hop up assy. The other length I could have gotten was 455mm but it would have sat inside the outer barrel and when the BB exits could have hit the outer barrel on the way out because there is some length taken up by the hop up unit.

[leblanc74]

Originally Posted by L473ncy

I have a 500mm inner barrel on an 18" outer. 500mm is actually something more like 19.7". Knowing that, my inner barrel does stick out of the outer by a little bit but it is still covered by the flash hider.

If I went with a 469mm inner it would have been more flush against the end of the outer barrel; that is 18" is about 457mm and the extra ~12mm is taken up by the barrel inside the hop up assy. The other length I could have gotten was 455mm but it would have sat inside the outer barrel and when the BB exits could have hit the outer barrel on the way out because there is some length taken up by the hop up unit.

Hey Bro...

Thanks for confirming that the hopup chamber assembly will compensate the differences in lenght, it makes sense...another way I was thinking is to purchase the longer one and cut off the inner barrel surplus/extra that protrudes out from the outer barrel, off course I will recrown the thing afterward; but I do not have that extra time for modifying anything anymore...