I was under the impression and Ive been told by the shop owner, who has seen this on numerous occasions and changed a few flared cylinders which have been damaged by over filling. I understand it to be a fail safe system to stop a total failure.
Ive never done it myself or seen it done but it seems other have. http://www.airgunbbs.com/showthread....damage-the-gun Post # 4,5,12 ....