DMR Build Probs

[Mad Magpul]

If the Bravo piston isn't working for you, just skip picking up the Lonex piston. The Bravo piston is a rebranded Lonex.

Okay that's what I thought so I'll just have to tinker with it for a while this weekend! Thanks for all of your help guys!!!

[Mad Magpul]

So after even more testing I have concluded that the piston was not set on the rails in the gearbox correctly. Thankfully that means I just need a new piston (the pick-up tooth on this one is shot) but thanks for anyone who helped me out in this time of need!!! As always I'm sure ill have one more problem before this project is over (I apparently just have that luck!) but thanks again to any one who takes time out of their day to help me!!!

[Mad Magpul]

So I'm pretty sure I have the worst luck when it comes to DMR building. I got the piston fixed and everything installed and I got one shot out of it before my anti-reversal latch broke in half. How this even happened I have no clue. Are SHS anti-reversal latches just that weak?

Edit: I have an old JG one, but I'm not sure if it won't break.

[Star_folder]

Hmmm, I wouldn't have imagined the SHS to break on you, but I can vouch for the JG being strong enough to handle what you are giving it. They are almost a standard for me, when an ARL is needed.

[Mad Magpul]

Well the whole build is, dare I say, looking very good right now, so hopefully I can break this thing out at TDC. As for the ARL the thing was literally brand new so I guess it was just defective. As for the hop up I have a King Arms 70 degree HQA bucking and I wondered if I should flat hop it. Would this give it any extra range or accuracy?

[Star_folder]

I would, Flat hopping a gun usually gives it more range and better accuracy. Especially with a DMR and heavy rounds.

[Mad Magpul]

So new problems!!!!! Yay!!!!
1. The gun fires fine at the beginning but after about 150 rounds I'll pull the trigger and it will only pull the spring back but not enough to release the piston. The next trigger pull will release the piston.
Not sure if this is due to shimming problems or over-heating.
2. This will probably be harder to understand but on semi my trigger gets caught and won't go back forward unless you manually push it back. On "Full-Auto" (converted to semi with a MOSFET) the trigger works perfect. Also on the actual semi, the trigger works fine until the gun cycles. So if I pulled the trigger without a battery plugged in on the actual semi it would work fine but plug in a battery and it jams and the trigger won't spring back to its normal position.
I know that was probably a little hard to understand so hit me up with any questions like always. I feel as I am now on the downward journey now so hopefully these will be the last of my problems!

[Star_folder]

1. This is related to a timing issue with the mosfet. Likely #2 is sort of to blame. You may need to reset the mosfet to the battery you are using on a full charge, and then set it to semi only. Once it starts up, be careful to make sure the semi auto gets a full pull. If the motor isn't warming up, it's unlikely the shimming or over heating. Does this happen just semi auto? Or just full auto? I would imagine you are doing these tests on full auto due to #2.

2. Your trigger spring is broken or not installed properly, the one that's actually on the physical trigger, not the one attached to the trigger sled. On semi, the spring on the trigger sled is still pushing the physical trigger back. Once semi auto happens, that sled is knocked off of the trigger, so your trigger no longer has a spring to reset it. On full auto, the trigger never resets, so that trigger spring will always engage the trigger.

[Mad Magpul]

So I guess I'll just change the trigger assembly and try to isolate the problem to see if the problem is in the sled or the housing. And I think that will fix number 1 because it seems to work on true semi.
Thanks

[Star_folder]

It's not the trigger assembly, it's the trigger spring. Has nothing to do with the trigger assembly itself. Most likely, the half shot at ~150rnds is due to using the gun in the full auto position vs semi. All you need to do is replace the spring on your trigger.

[Mad Magpul]

Well I already replaced it with a stronger one and its in correctly when I close the shell but I'll triple check tomorrow and tinker with it. As always thanks TONS Star.