Oil will do no good as it cannot really get there to the threads.
An allen with 3/8th socket so you can use a regular ratchet... The do the pre-load on the wrench as I suggested above and "ring" the bolt with hammer taps... A "deadblow" hammer is best for this.
It cracks the loctite bond.
Loctite is simply super glue aka:cyanoacrelate in predetermined max strength...
Took it out shot it today, works just fine. Got the Grip off too
. Probably just some freak thing with that round as I put through like 30 rounds today. I don't think the gun was broken in. In any case it does feel like a decent quality pump.
I really appreciate everyone's help.