All I will say is my GSG-16 currently has a 9 inch barrel installed and I have 700ish rounds through it. The rifle still functions fine and the accuracy is surprisingly good. So in saying that I can confirm that having a short barrel does NOT cause malfunctions only drawback is having to pin the stock but that is a sacrifice I can live with.
Anyone have any idea at what point a collapsible stock needs to be pinned?
Ypu giys planning on getting the 3 barrels and shipping what needs to be shipped today? Thanks again