I mailed mine Friday to Baker airguns for pump rebuild. Don't know if they can help with barrel separation. Mine did the same thing a couple years after I bought it and sent it back to Sheridan but that was in 1977.
I am going to send a airgun in for service and was wondering how you guys prefer to ship. Everything I get thru UPS seems pretty beat up so I'm looking for options.
I was under the impression the FX boss was built to shoot the JSB 44.75 gr. I haven't check it in years but mine was shooting in the 860 range. Sometimes it's about what the projectile wants not just the gun.