Today I looked into a similar setup w/ IMC coming in, and it did have 2 lock nuts--inside & outside--but then there was a red plastic bushing over the very end, to protect the insulation on the conductors.

Not sure if that's code-compliant, but it seems reasonable and adequate as far as providing a flared/beveled/soft transition zone for wires to enter conduit.

Only remaining question is, do the two locknuts constitute adequate GND bonding? Seems to do the job on EMT connectors.

Don't everyone pipe up at once... you'll cause a "Denial-Of-Service" clog on my converted telegraph wire internet service, lol...

I don't know your local code on this, but here it is a question of wire size for bushing requirements, having said that, you can never go wrong putting on a plastic (or metal)bushing to protect the wire. A pair of nuts(inside/outside) PROPERLY tightened is adequate ground.

Thanks, I've got the plastic bushing, and locknuts, and spanner thingy, and will go with that. (Not sure how I would tighten the chase nipple anyway, w/ box against wall, etc... UNnecessary complication.)

I'm just running two AWG12 THWN through a 1/2" nominal dia. RIGID nipple, to a single-gang wet-loc box w/ 20A GFCI--VERY short run... NOT in a seismic zone, lol.