The ring of the ram has the following description:
The force of the blow is considerable, and those struck by the ring are subject to a bull rush if within 30 feet of the ring-wearer. The ram is Large and uses the ring’s caster level as its base attack bonus with a Strength of 25. This gives the ram a Combat Maneuver Bonus of +17. The ram gains a +1 bonus on the bull rush attempt if 2 charges are expended, or +2 if 3 charges are expended.
If I am a 4th-level paladin/2nd-level fighter with effective caster level 1st, does that mean I only get a base attack bonus of +1? Or is "caster level" reflective of the CL of any PC that uses it? and in this way, does a rogue have +0 to BAB, etc. or would I have a "Caster Level" 6th because that is my CL?