<VV> Grease fittings

[Ralphsebrell]

I had occasion to drill and tap and install a NEW grease fitting. It was hard to get the gun on and even harder (VERY hard) to get it off. This was also a new gun, so I thought it's the gun, but an old gun was hard also.
My FLAPS guy was likd "I don"t know"
The threads were metric. The nipple the gun goes onto could screw out. Making the fitting a 2 piece thing.
Do any of you fine folks have any idea what's up with this?
Ralph