Maverick 88 issue

[tree_ghost]

So I have a Maverick 88 20ga for my oldest son. I picked him up a Carlsons .565 TSS with browning invector threads which are supposed to fit but for some reason this one won't. I threaded another Browning Invector choke in the gun just to make sure it wasn't an issue with the barrel. Anyone know why this choke won't fit the gun?

 

[jeff gra]

Could be a invector plus that was labeled as an invector.