The bumper on the mag is a little large so you might not be getting a good seal on the fill valve. And you may want to hold the can on the mag for at least 6-8 seconds to ensure you have a good fill. I believe the pistol came with an extension for the fill nozzle of green gas cans so you could use that as well. I have a propane adapter that I use on mine and it is long enough and I rarely have problems with mine, invest in one of those. Another thing is the temperature of the gas it might be too cold, don't know how in this heat but that could be the problem. Try these and let me know how it works.
