Mcbros 50bmg action for 416B

[flims]

I have recently acquired a single shot mcbros 50bmg serial number around 700T, i believe a 1997 model. It's got abt 400 rounds down the pipe. I wanted to use this action as a donor action for a 416Barrett build.

Anyone has first hand experience with this? Some 2 or 3 known gunsmiths told me that this action/bolt has low primary extraction and may not be ideal for competition use to extract spent 416Barrett brass. Any known issues in this regard and how would it be different than extracting a spent 50bmg case if it were a 416B brass?
Thanks!
Rod