Cast to ABS Coupling - shield buckling

[jmterail]

I'm doing an ABS to cast transition.

4" cast connected to a 4" to 3" ABS bushing.

The bushing has a spigot end that should be identical diameter to 4" ABS pipe, so I figured a regular hubless 4" shielded coupling would work. (I used this one: https://www.americanvalve.com/product/rnhhd/)

Problem is, the diameter of the cast seems to be slightly off - it's a slightly larger diameter than the ABS, to when tightened, the coupling shield buckles (since the ABS-side clamp has to be tightened more than the cast-side clamp).

I poured some water down and it doesn't seem to leak - but it doesn't look to pretty (pic below).

Is there a better coupling for this?

Also wondering if I can wrap the ABS with a bit of sealing tape to increase the diameter to better match the cast?

 

[voletl]

That is a tubular by pipe transition coupling. You need a diffrent coupling.

 

[jmterail]

Gaa, you are right.

That was all the big-box stocked.

Looks like ideally I would go for a fitting specifically designed for cast to plastic - https://www.fernco.ca/sites/default/files/dimensional-drawings/pdf/3000-44.pdf

No idea where I could buy one though.

Home Depot also stocks this one:

https://www.homedepot.ca/en/home/p.no-hub-coupling-4.1000117478.html

Says it will connect plastic/cast iron - but something tells me it's going to be the same issue as with the last one - where the fitting is not designed to accommodate pipes of slightly different sizing.

 

[Geofd]

the older cast iron has 2 different markings (sv service weight) (xh extra heavy) they both are larger abs/pvc you can find these couplings at a plumbing supply house