What length of the barrel is within the receiver of FX Impact M3?

[BillG]

Ok Impact guys. I need to know how much of the barrel is inside the receiver. Or, what's the measurement from the mag to the front of the receiver? I've been making barrel for these things and have recently began making them heavier. This means I'm going to have to turn them to the smaller diameter to fit the receiver. The Maverick is 290mm, would the Impact be the same?

Any help will be greatly appreciated.

 

[Ca_Varminter]

Roughly 335mm from the rear block to the end of the Front extended barrel block