I don't have anything special for the 129 which I am still working with H4831SC. I started with the 123-125 data in my 6.5x284. I noted Nosler had come out with data for the 129 and 26 Nosler and 264 WM. The data I saw supported that decision.
The tested COAL was a little different but the 129 ABLR runs about a grain more than the 130 NAB. I will use the 140 data for the 142 and expect to be able to exceed it the bearing surface of the 142 is significantly shorter.
I am sure Nosler will have data on their web site soon.
I have 6 each of 56.0-57.0 in .2 grain increments to run some ladders on the 27th, started working with Retumbo last year with 140AB. Got my hands on 500 142 ABLR, switching over to them. Contacted Nosler for data, was told could use the 140 data that I had already been working on. Interestingly, was told to seat them off of the lands, Nosler says they start them at .050 off and adjust them from there. I'll stay up on this thread, post with my results.
I figured someone has to have a recipe for this combo. Right now I am using 58 grains of retumbo with my 140 Bergers. I figured the 142 ABLR cannot be too far off from there, less if anything as that is a compressed and max load.