It’s because you’ve bought a tiny disposable gas bottle. You were advised in the other thread that they were a waste of money, last literally minutes and as you’ve found out completely useless at delivering decent flow rates. Mig welding the flow rate varies depending on situation and shroud size but to give you some idea you want more than double what your getting to start off.I got myself new gas bottle high pressure together with new high pressure valve and all I can get maximum is 5l/min ? That's pretty low for maximum settings I think , not sure how much I need welding outside.