TLDR: Use your headhunter/ultimate on buy rounds, and buy rifle on save rounds so the rifle can be recycled by teammates and help win eco rounds.

As Chamber you will sometimes be in a position where you can full-buy and you have your ultimate ready/almost ready and your team cannot full-buy (you have better eco due to having your headhunter). If your team decides to eco-buy (“buy for next”), 99% of Chamber players will use their ultimate for the eco round and then full-buy the next round with the team. IMO this is a big missed opportunity.

What you should do is full-buy a rifle when your team is on an eco-round and then use your ult on the next round (the “buy” round). The reason is that a rifle can be picked up by a teammate after you die and give your teammates a better chance of winning a later gunfight…your ultimate cannot be picked up by teammates. Depending on your skill, you can even apply this just using your headhunter on buy rounds. 8 bullets is more than enough to take down an enemy and get their rifle, and you have saved money so you can buy a rifle the following round and recycle it through your team.