Finally decided to make an account here, but have been stopping by regularly for my ar-15 info source.

Anyways, I took my gun (SIG M400) out to the range last week and about half way in, i noticed that i would keep getting random double fires. I tried to slow down the process to see where the error was happening and found it was upon SLOWLY releasing of the trigger after a shot (if i just let off the trigger quickly it usually catches into the correct spot) instead of resetting to fire the next round the hammer would just slam up and fire the next round. I broke down the rifle and checked the trigger to see if there were any chips/cracks/scratches and I found some seriously weird looking Deep scratches on the disconnector.

http://www.fotoshack.us/fotos/46596Disconnector.jpg

as you can see it has these weird scratches all around on it. but on the bottom lip there is a very noticeable "gouge".

These are the only "defective" looking spots i can find in the trigger group and I am just wondering if you guys think that this could be the reason for the problem?

Sorry, the pic isnt that clear. shot off iphone 3gs

Replace the disconnector. Quick question, when you squeeze and hold it should fire a round. When you release does it fire a round too??  2 rounds one trigger pull. Post pics of the hammer and trigger contact points too

Also the correct sub forum for this is "trouble shooting " forum.

Welcome to the site

The part is defective. It's a stamped piece that should not have ended up in a gun. Most will have some funkiness around there, but yours isn't right/out of spec.

Get in contact with the manufacturer and get a replacement ASAP.

yep, 2 shots 1 trigger pull. but like i said, it's almost Always when i slowly let go of the trigger. after it fires the first round, if i let go quickly it usually resets correctly. going to take some pics of everything else here in a couple mins.

Get some new parts. I can usually make an older gun double fire by rolling my finger off the trigger to see if the disconector  releases. Range weapons mostly. But your better off just buying some replacement parts and installing them.

My recommendation is to get a FCG of the EE or a mil spec trigger group from an industry partner.

Im guessing you didn't do a function check before you took it to the range, that's what it is for.



Get a replacement, install, DO A FUNCTION CHECK, then go to the range.

TaylorWSo is correct. Function checks are a must.

The pictured disconnector is normal for a die struck 1050 spring steel part. As long as the hammer engagement surface is not damaged or ground improperly, the disconnector should be fine. Colt disconnectors are made from 1070 spring steel and are fine blanked. The harder material and manufacturing method produces a cleaner part.

Function Checks


ETA: I'm not suggesting there isn't a possibility that the pictured disconnector could be out of spec, I'm just saying that "striations" do not immediately red line the part.