Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

I was looking through the Space Marine codex and I found something:

in the entry for the Infiltrator Squad under Infiltrator Comms Array it says "...if there are any friendly <chapter> Phobos Captain or <Chapter> Phobos Lieutenant models on the battlefield, this unit is always treated as being within range of those models' Rites of Battle and Tactical Precision abilities."

under the stratagem Chapter Master it says you remove the Captain keyword with Chapter Master and replace Rites of Battle with a different ability called Chapter Master.

Am I right in that if you use this stratagem on a Phobos Captain an Infiltrator Squad with a Comms Array would not gain the ability to reroll hit rolls outside of the regular 6" bubble?

Correct, as written changing the keyword breaks the ability.

Correct, the ability only works with CAPTAIN and LIEUTENANT models, of which a CHAPTER MASTER is neither.

FAQ confirms the above. Chapter master doesn't work with the comms ability.