Hephaestus m4 trigger assembly problem
 

Hello I have a problem with the Hephaestus steel trigger kit that I installed into my WE hk416, on semi automatic it fires the first shot fine but after that the hammer gets stuck and will not be released by a trigger pull; it seems to get caught on something if its cocked with he trigger pulled back and will only be released if I push on the hammer thereby releasing it. Anybody have any experience fixing this problem?

hey i have the solution I've modded a few pairs, it's quick work and only takes 10-15 minutes.
You need to do two things, first the trigger has a grub screw that adjusts for the sear, you need to raise that up correctly and then add a bit of material on the opposite side a small bit of aluminum from a pie pan or jb weld putty just to solidify the area so the sear resets when you release the trigger.

I have Hephaestus steel trigger pack install in my WE m4 and m16. I have been using both rifles heavily(1000 rds a week)for almost a year and they work great. Having said that, this trigger pack require a lot of mod(grinding and polishing here and there) to work but, after all mods have been done, it works great.
The quality is OK. Hammer seems to be constructed of zinc plated steel which is much stronger than WE stock trigger. Trigger seems to be constructed of steel. The rest: dis connector, valve knocker, valve knocker delayer seem to be constructed of manganese which is considerably strong. Finishing isn't that impressive though. Machine line is visible on most parts except trigger. Metal contact surfaces are also rough.
Dimension of most parts seem identical to WE stock parts in a glance yet it isn't. First of all, the engagement angle of dis connector and sear is off. Contact surface between sear and hammer need to be correct to match the point where dis-connector disconnects. The surface need to be gently grind down until the angle is right. Dimension of valve knocker delayer is off so much that modded WE stock delayer is to be used instead. You must have basic tools like small vise and a set of file or Dremel tool to do the mod. I'd recommend using file due to Dremel might remove the material too much and once it is done, there is no turning back.
I chose Hephaestus trigger pack primarily because it is the cheapest steel trigger pack out there for WE m4s that I know of. I did not expect much for both quality and functionality, to be honest, due to it being cheaper than others(RA tech pack cost 100+ and CWI cost 140+ as of 2015). However, it is a good experience for me to be able to trial and error and finally make it work. If you are, like me, like to get your hand dirty and do not afraid of failure, you will enjoy it quite a bit.