I checked with a few manufacturers, as well as with MRI.

Response from Lee:
Yes, we do have a die set coming out soon: https://leeprecision.com/3-die-set-429- ... eagle.html

Response from Hornady:
Thank you for the email. At this time we are not. I will pass on a suggestion and see what we can do.

Response from MRI:
We expect to have the dies here and ready for sale in aprox. 6-8 weeks.

The next step will be to get some of the bullet, powder, or loading equipment manufacturers (or even MRI - hint, hint) to start working up data. Something developed with actual pressure equipment is going to be better than us home reloaders just watching for primer flattening. Having viable support for reloaders is paramount to making this semi-wildcat round a success.

But I expect we should be able to safely get above the velocities listed for the current .429 factory ammo. I can get over 1500 fps with a 240 gr .44 Mag now, using published book loads.