That is correct. For rounds that headspace on the shoulder, the base of the cartridge may not be on the bolt face if the headspace is off. When fired, the case will stretch until the base of the cartridge hits the bolt face and the stretching could cause a case rupture.
If the headspace is too long. If too short it won’t chamber or when fired won’t extract. Headspace is not the length from base of cartridge to bolt face. It’s from chamber to bolt face. You adjust headspace at the barrel/receiver. The bolt itself has no adjustment.