I shoot the NAP slingblade which is very similar to the NAP Killzone. The only difference being the Killzone locks in the open position and the Slingblade don't. The Slingblade is pretty easy to open by hand. So I think you may have a damaged head.

 

i have two packs of kill zone 2" brand new with the practice heads I would mail out cheap tmrw. My daughter bought them for herself when I sent her to get a different brand. The guy at the register told her the NAP was better. I have confidence in another head so it will be all we shoot.

 

Lost a 170 class deer on it. Granted it was 60 yard but with Ravin that shoots over 400 fps. I don't think it deployed fully but not sure.

 

Just saw I posted this almost a month ago, no reply toy email from the company. Guess they have plenty of business, they don't need mine.

 

I also sent an Email to NAP a few weeks ago. No response.

 

I killed two deer in Ohio this year with the 100gr Killzone on an Evo X center punch arrow out of a TP Viper S400. Both deer were slightly quartering shots and both suffered tight shoulder hits. Massive entry wounds. The buck traveled about 40 yards and fell over dead. First season I used the Killzone but I’m happy with it.