Autofocus on EOS R6 with the sigma 150-600 f5.6-6.3 C

[voletco1]

So, I currently own a canon 7d mark 2 paired with the sigma 150-600 C version and a sigma 24-70 f2.8 A. I want to upgrade to fullframe in the near future (R6) but I‘m wondering if the well known issues (focus pulsing) are really that bad, or if it can be fixed somehow.

[March411]

voleteco1, if you do a deep dive you will find that there are many using Sigma lenses on R bodies with great results. The challenges were isolated and resolved but people kept posting inaccurate information. The challenges I believe were specific to the R7 and not the lenses themselves, a firmware update solved the majority of the challenges people were having with pulsing/racking.

I own several Sigma lenses all of which perform excellently on my R bodies using the Canon adapter. I tried third party adapters and they were a waste of time and energy.

The key is ensuring the firmware of the lens is current using the Sigma dock. I own the Sigma 60-600mm and had some challenges and reached out to Canon support. They instructed my to update the firmware, I did and the problem resolved. My 100-400, 70,200, 24-70 and 18-300 work flawlessly. 

This is an image using the 60-600mm on my R6 MkII

[Tronhard]

I have the R5, R6 and R6II camera bodies and have used the Sigma 150-600c frequently with them and with no issue.   The issue with regards pulsing was specific to the R7, as explained in the following video:
CANON RESPOND, THEIR ADMISSION SURPRISED ME! (youtube.com)

There are, IMHO, a complex series of issues with that specific body, but I have had no such issues with the FF MILC units, like the R6.   If you look in the Gallery section > Share your photos, you can search for examples from several contributors, but to get you going here are a couple.
First the R5 with the Sigma 150-600c - at 45MP this is a more demanding camera with the same focusing system as the R6.  Testing the Sigma 150-600 Contemporary with the Ca... - Page 2 - Canon Community
The R6 with the 150-600c: Sigma 150-600c on a trip to the zoo - Canon Community

I eventually sold the Sigma 150-600c because I also have the 60-600s and a couple of RF super tele zooms, but it was not because of any perceived shortcoming of the lens, just economics.