A mix chamber for a plural component sprayer is configured to receive first and second component materials and emit a spray of a resulting plural component material. The mix chamber includes a chamber body extending between a first end and a second end and including flat lateral sides. A ramp feature is disposed proximate the first end and is configured to contact and push first and second side seals, respectively, away from a body axis as the mix chamber shifts in a first direction through a cartridge bore to increase a gap between the first side seal and the second side seal such that the first side seal engages the first flat lateral side and the second side seal engages the second flat lateral side.