Nerf: Hammershot Spacer - Upgraded Retaliator Spring

Nerf - Zombie Strike Hammershot Ultimate Upgrade
Nerf - Rebelle Sweet Revenge Ultimate Upgrade

Upgrade your Nerf Hammershot to the best possible performance using this spring compression spacer and a secondary Upgraded 8kg Retaliator spring

Upgraded Retaliator 8Kg spring: http://modworks.blogspot.com/2012/07/nerf-n-strike-elite-retaliator-mod-guide.html

Other modifications can be found at Better Nerf By Science: http://nerfscience.blogspot.com/2013/09/the-works-guide-zombie-strike-ham