Spring Lock have a new replacement chamber named the “W Hold Chamber” for the VSR-10 series which is, according to their product page, also compatible with the TM pistol line:
Dear Sir, Today we want to inform PDI new products. W hold chamber packing.
This is for TM VSR-10 original chamber(called G chamber),so available to TM GBB pistols as HI-CAPA(5.1,4.3& EXTREME) , Glock (26,17,18C), PX4, DETONICS, 1911, MEU & SOCOM. It has two ring ribs on the outer surface to improve airtight. And has "W hold ribs"inside. Two ribs in the packing are steady of the BB’s trajectory.
Hold BB at the best position,so this packing will bring better accuracy.
In this new one, set the special rib inside to keep airtight
It made of nitrile rubber(Hs50), and has high oil resistant and abrasion resistance. You can use it all season!