Jard trigger issues - help!

Lasr month I bought an MP15-22 MOE and stuck about 1000 rounds through it without issue. It ate CCI mini mags, CCI standard, Blazer, Aquila etc without a single failure.

Last week I installed a Jard single stage non-adjustable 3lb trigger (see below for instructions)



I put about 150 rounds through the rifle and had a few light strikes (about 4) and the hammer pin (part 8) kept slipping out of one side of the receiver as the pin keeper (part 9) wasn't seated properly. I took it home and re-seated the pin keeper so that it fit snuggly into place. I also installed a Battle Arms Ambi safety (the one specifically built for the MP15-22).

When I went back to the range the following day I immediately had problems. The hammer would not re-set after firing a shot. The rifle would eject the spent round, chamber a new one, but the hammer had not re-set and so you had to re-cock the rifle to get it to fire again. It would do this once or twice in a mag of CCI standard but the hammer would refuse to re-set at all using the more powerful CCI mini-mags.

I took it home, removed the trigger cleaned and lubed it all and put it back in. I tried again at the next range day but the hammer was still refusing to re-set.

Thinking about what I'd changed since it intially worked with the Jard trigger installed I removed the pin keeper plate and the Battle Arms safety (I ran it without a safety at all), but the hammer still refused to re-set after firing a round off.

I've triple checked that all of the springs are installed the right way. I've checked that the pins are seated correctly and are not moving. I've looked at the grip (which i removed to install the ambi catch) to make sure that the bolt was not interfering with the trigger. I've function checked the action with the upper removed and all looks to be working normally.

I am at a loss as to what could be causing this issue. If the Jard hadn't worked when I first installed it I would probably have given up by now, stuck the original trigger back in and tried the Jard in my AR15 instead. Thing is though that it worked okay when I first installed it (except for the pin keeper not being seated properly and the hammer pin coming out).

One guess remaining is that I might have bent the hammer pin when it came lose; not sure if this would cause an issue with the hammer failing to re-set though. I am trying to get a set of KNS anti-rotation pins (the longer set made for the MP15-22) but they are difficult to get here in the UK as not many people will ship them abroad (Brownells don't appear to have the MP15-22 version in stock).

I have tonight re-installed the original trigger and will test it out on Friday. If the rifle shoots okay then at least I know it's an issue with the Jard trigger and not the pins.

Any thoughts or ideas are welcome as I'm all out!

Is the disconnector properly timed? Take the upper off and thumb the hammer back while holding the trigger fully to the rear. Let go of the hammer. Does the disconnector catch it? Release the trigger. Does the sear catch the hammer or does it fall?

imashooter2 said:

Is the disconnector properly timed? Take the upper off and thumb the hammer back while holding the trigger fully to the rear. Let go of the hammer. Does the disconnector catch it? Release the trigger. Does the sear catch the hammer or does it fall?

Click to expand...

Yup, fully checked, I must have done this about 100 times by now and it works every time, catches the disco then tbe sear perfectly.

I can tell you that the there is little tolerance in the hammer trigger relationship. It must be almost exactly in the correct place or the rifle will not function correctly. Even factory new my pin locations were off ever so slightly which caused the hammer to not fall at all sometimes. I just slightly filed of a little bit on the disconnector and have been good ever since. In your case I would say the disconnector is not catching the hammer or the sear is not engaging. This can be caused by the trigger not in the proper position. Do you have anything that restrict the trigger from moving completely forward or backward?

Try to squeeze the trigger and hold as the hammer falls. Then while still squeezing the trigger cock the hammer and release the trigger. Does it still cock?

In normal firing the trigger would be held to the rear as the hammer re-cocks so this is how you need to check it. The disconnector needs to catch the hammer at this stage and then when you release the trigger the sear engages.

Rundover said:

In normal firing the trigger would be held to the rear as the hammer re-cocks so this is how you need to check it. The disconnector needs to catch the hammer at this stage and then when you release the trigger the sear engages.

Click to expand...

Disco and sear work perfectly every time I function check it. Holding the trigger down I reset the hammer which catches on the disco. When I release the trigger the hammer is then caught by the sear. Pull the trigger again and the hammer is released.

Interesting. Well if it functions correctly every time then it must not be the problem. When a round fires the bolt is blown back which cocks the hammer. If something was stopping the bolt from its full rearward travel it may not be able to cock the hammer. Are the rails that the bolt rides on flat and smooth and does the bolt easily move all the way back?

I have heard of people separating the upper from the lower for cleaning and the bolt has fallen out onto the floor bending the rails.

Bolt is okay, rails are fine too. I pretty much clean and lube it after every visit to the range.

I'll report back after my trip to the range with the standard trigger back in. I'm almost hoping that the problems persist, then I can rule out the trigger as the problem and look at the pins.

This is odd. Trigger works fine and the bolt is fine. This just doesn't make sense. Standing by waiting for the results.

I'm due down the range tonight @ 7pm GMT (About 6hrs time) . I've re-installed the original trigger and will see how I get on, but in the mean time I found this interesting exchange on another forum which seems to mirror my issues (but involves a RRA trigger not a Jard).

............ Same problem after all the oil I put on it. But this time I was able to pay more attention. Chambered the first round and fired, ejected and loaded next round... pull the trigger but this time I heard no hammer click... so I manually eject the unfired round and loading the next one and it fired just fine and the the next one doesn't fire again with no hammer click... but i checked the unfired rounds and they do have a light fire pin mark on thr primer. I don't know what's wrong, I hope I explained it clear enough 'cause this is all new to me. Does anyone have an idea on what's causing this? Thanks

Click to expand...

This was the response

Got to be the disconnecter or trigger allowing the hammer to follow the bolt down after the first shot. In other words, it isn't staying cocked when it fires one round.

I'd get on the horn with RRA and have them send you a call tag for warrenty repair & safety checks.

The little primer dents are normal in all AR-15's, and are caused by firing pin bounce when the bolt slams shut.

Click to expand...

and then this

You're right! The hammer gets stuck on the disconnector ( top part ), I have to push the trigger foward to release it and then I can pull the trigger and it goes. Should I file or sand it down a bit to smooth it out? Maybe put some more oil :/ ??? At least I'm in the right direction : )

Click to expand...

Now all of this got me thinking. When I was having my issues I was assuming that the hammer had not re-set as the safety was off and the trigger was pretty solid. When I looked inside the rifle the trigger was not back on the disco BUT I do remember on at least one occasion the hammer coming forward as I opened the rifle up. So maybe the issue is with the disconnector not letting the hammer fall after the first shot is fired? (although it function checked perfectly when I had it open and was manually pulling the trigger back?)

Once I've tested the orginal trigger I'll put the Jard back and try again, paying more attention to see if the trigger is caught up on the disco or if it just isn't re-setting properly. If it is caught on the disco then should I think about filing doen the disco spring a little?

JP has a great video on timing the disconnector.

original_FC_inst2

The disconnector bit starts about halfway through.

Went to the range last night and tried out the original trigger and the Jard trigger again.

The good news is that the original trigger worked perfectly, it shot every type of ammo I tried to use without a single problem.

Bad news was that the Jard still played up. I had previously removed the disco and smoothed out some of the edges I could feel with a whetstone and so I was hoping it might have solved the problem. No luck though, it still failed to reset the hammer on some shots, I've posted a short video of the range trip below.

trigger testing - YouTube

It seems to me that the hammer spring is to hard, which prevents the bolt to push it back enough to engage the disconnector. This happened to me when I tried subsonic ammo. The ammo was not hot enough to push the bolt back. Why don't you try to swap the hammer spring to a weaker one like the OEM spring? I am pretty sure that will work!
Have a nice day
/Elmerviking

Hmmm. Not so sure about that as it seemed to cycle standard CCI a lot better than mini- Mags. I think its a timing issue with the disco.

A weaker hammer spring = possible light strikes. I still believe it is the disconnector. It possibly is just slightly off timing and is why it works sometimes. The trigger is adjustable so I think now would be a good time to learn how to adjust it.

Rundover said:

A weaker hammer spring = possible light strikes. I still believe it is the disconnector. It possibly is just slightly off timing and is why it works sometimes. The trigger is adjustable so I think now would be a good time to learn how to adjust it.

Click to expand...

This is a non adjustable trigger according to the pic. I have a Geissele SSA-E trigger and had to use the OEM hammer spring because the Geissele spring was a bit too strong and would not cock the hammer. You will not get light strikes with the OEM hammer spring unless the Jard hammer is much heavier than the S&W hammer, which I doubt. Strange behavior ...can you feel any difference in the creep with the Jard hammer (i.e. Is the engagement not long enough)?
/Elmer

(Will be interesting to know what you find out...let us know)

Oops, sorry wrong trigger.

Yeah- I bought a non-adjustable trigger because I didnt want to have to muck about with settings to get it to work!?!

Okay, next visit to the range will be Wednesday after work. I'll try the Jard trigger with the OEM hammer spring and will post up results.