Storage and mixing systems and methods for pasty multicomponent polymethylmethacrylate bone cements, the systems and methods comprise a first tubular cartridge with a first cylindrical internal space containing a first starting component, a first dispensing plunger, a second tubular cartridge that is arranged within the first tubular cartridge. The external wall of the second cartridge touches against the internal wall of the first cartridge and is attached to the internal wall of the first cartridge, whereby the second cartridge contains a second starting component and has a second dispensing plunger arranged in it, whereby a pressing device with a clamping edge for compressing the second cartridge that can be propelled axially in the internal space of the first cartridge is arranged, as seen from the cartridge head, behind the first dispensing plunger and the second dispensing plunger. The pressing device can be propelled appropriately in the direction of the cartridge head such that the second cartridge is being progressively compressed axially during the motion of the pressing device such that, in the process, the first dispensing plunger and the second dispensing plunger are propelled in the direction of the cartridge head.