I have found some problems with recent Coleman propane bottles. I have found that recent bottles marked with lot numbers starting with 05xxxx appear to be subject to some tooling changes at Coleman's factory.
Signs that you have a problematic bottle:
-Tank end of propane adaptor is difficult to remove from propane tank
-Propane adaptor "locks" open and sprays propane even when the GBB magazine is removed from the fill probe
Cause of adaptor issues with recent tanks:
-Plastic retaining ring (white ring) which traps propane tank oring is pressed too deeply
-Over pressed retainer ring does not allow space for oring to deform into when tank end of the probe
-Trapped oring binds with adaptor probe preventing it from moving freely
Older tanks have a small gap (approximately 0.05") for the oring to deform into. Newer tanks have no gap.
I'm working on a simple tool to fix this problem. It's made of readily available parts. I'll be making a post soon detailling how airsofters can make their own tool made from parts that can be obtained at hardware stores. I'll also be carrying the parts which will be supplied from my online stores.
If you've had the problems that I've described above, please look for the lot number printed on the lower half of the bottle and post it here. The lot number is printed in dark blue ink and usually has 6 digits followed by 4 digits that look like a time stamp e.g. 052306 18:27