What about a close nipple and (4) locknuts? That should ground things nicely.
SceneryDriver
A bonding jumper between enclosures works as well. You have 3 things that need bonded, enclosure A, enclosure B and the raceway with associated fittings. So if enclosure a is bonded, the locknut on enclosure A side will bond the nipple, but enclosure B with teh "chase nipple" end may not be bonded if painted surfaces are involved, you can either remove necessary paint or use a bonding jumper to ensure enclosure B is bonded - that is how I see it. A close nipple with 4 locknuts does remove the need for the bonding jumper, but also means the two enclosures are not in same position as they are with the chase nipple connecting them together. Sometimes that difference in the space between is very important to the installation.
For what it's worth according to the wording of 300.4(G) a chase nipple cannot be used with conductors #4 or larger since one side does not have an insulating material.
I agree that is what is written, I also think that wording needs changes and have a feeling the intent there is not to prohibit the use of a chase nipple - but I could be wrong. That said I have used chase nipples for conductors #4 or larger many times and have never been called out on this by an inspector. But it is no different then the earlier mentioned driving over the speed limit doesn't mean you will always get a ticket for it.