I like to use nesting couplings as reducer bushings, because I can stock one part and use it for two purposes. However, I've found that when I'm pulling a lateral line that consists of say, 40' of 1" and 20' of 3/4", 1 out of 10 times it will pull apart where it bushes down during the pull. I usually bevel a 3/4" nesting coupling, and glue it directly into the bell of a 1" pipe, and then glue in the 3/4" pipe. This failure is too high in my opinion, and it always happens in that spot. Does anyone think that switching to a regular style bushing would work better? Or perhaps a different glue (I use IPS 725 without primer)?