I recently got a Gameface Prime and upgraded it with all worker metal inernals(silver power/w extended barrel, bolt sled, catch, &trigger) plus this spring. Description says not compatible with ceda s but I know it works with the gameface. No priming issues at all. Properly tuned hits between mid 230fps to mid 250fps depending on darts. Great spring upgrade and for the lower 200s I use my turf spring. I will look at 17/32 brass barrel in the future for more performance if needed. This spring is great.