FTF??

[aklaunch]

Today i got a new rifle scope in the mail and went to the gun club to sight it in.


For this particular rifle i use only factory 5.56 rounds and have never had one problem. It may have 1500 rounds through it.

I had an assortment of XM855 in the 2009, 2011 and 2013.

The plan was to sight it in using the 2013 as i just got a big batch of it. The 2009 and 2011 where just miscellaneous magazines in my range bag.

Short story long i had 4 or 5 occasions where i would pull the trigger and nothing would happen because the trigger would/was not reseting.

Seems i would get a bigger bang than normal, then i could not feel the click of the trigger reseting as the BCG cycled.

Each time there was a new bullet in the chamber ready to go but the trigger was not reset.

The first couple of failures i started changing mags and ammo. Seems to be a trigger issue.

The only thing i did different than normal the night before was lube the trigger.

I installed another Geissele trigger on another rifle and used the spare lube can to re lube the affected rifles trigger.

Anybody think i put to much lube on?

I got home and took everything apart and can't see anything abnormal.

Thanks

[Eric]

If you're experiencing substantially louder noise from some of your rounds (assuming the same type/lot/etc.) you have an ammo issue. While some variations in report can occur, they are usually minor.

More details would be helpful. Type of rifle? Factory or assembled from parts? Type of trigger?

Assuming a standard FCG, is it assembled like the one below?
http://img.photobucket.com/albums/v503/AR15forme/FCG.jpg (http://smg.photobucket.com/user/AR15forme/media/FCG.jpg.html)

Lube, unless ridiculously excessive, should not be a concern.

We also need to ensure that your getting full function of the action, meaning the BCG is traveling all they way to the rear and resetting the trigger. Load a single round in the mag and fire it. Does the action lock open on the bolt catch?

[aklaunch]

Thanks for the reply.

Yes sir, the bolt does lock back after the last round.

The rifle is an LMT and the trigger is a correctly installed Geissele. I have fired just under 2000 rounds without 1 single hiccup.

I am baffled.

More experimentation tomorrow or the next day.

Will report what i find.

[aklaunch]

After enough scouring over the internet i have found the issue.

The Super quick reset 3G triggers are not designed for bench rest shooting, due to the quick reset.

I did not mention i pulled off the bipod from another rifle and put it on yesterday. I have never shot the rifle/trigger combo off the bipod.

That combo has not had 1 single issue since yesterday.

I think when you put a trigger with a super quick reset in a bench rest position you run the risk of it bumping and or the trigger not reseting. This is because in the bench position the stock is not always glued to your shoulder, creating a recoil gap that in itself is conducive to bump fire or the trigger following the BCG and failing to reset.

[aklaunch]

The saga continues.....

Today i had the opportunity to be a part of a practical rifle match. 2 out of the 4 starts my rifle jammed up.

The 2 hang ups i had each consisted of a different magazine.

I have a B.A.D lever. The first trial of the day i had my bolt locked back. I inserted a magazine and instead of using the B.A.D. lever i pulled back on the charging handle. The round got stuck in the M4 feed ramp. Also made a huge gouge in the bullet below it.

On the 3rd trial with another magazine from another manufacturer i had the bolt locked back again. Understanding the concept of not riding the charging handle forward i tripped the B.A.D. lever. Same thing....... Another jammed up bullet.

Both instances the 30 round magazines where loaded with 28 rounds.

When i got home i was disturbed...

I was able to replicate the failure over and over again in my back yard.

A clean full recharge of the handle would chamber a cartridge.

Tripping the B.A.D. lever would repeatably chamber a cartridge. (though one time at the match it did not)

With the bolt locked back and not using the bolt release. - Recharging the handle to the full aft position would repeatably not work. Bullet nose plum stuck in the M4 feed ramp.

These are 55gr FMJ from Federal by the way.




I walked away and then came back.


First thing i did was pull my bolt out. Feels gritty and sticky... It is harder to work than some of my other rifles bolts. (Colt and DPMS)

It seems as it is getting more sticky with time?

I made a plan to change the gas rings out. I put the bolt in my vice and played with the rings. They felt fine..... I did not feel like replacing perfectly good rings. So i pulled the Buffer spring out. Measured and it got a passing score of 10-1/8th long.

I measured the new Brownells spring and got the text book 10.5 inches.

So i put it in. cycled and cycled the rifle and am not having the problem anymore.


This is funny how the last time i shot the rifle it would put a cartridge in the chamber but the trigger was not set. Today it did not want a cartridge to go in the chamber.


Point is... I honestly have no idea how many rounds i have through this rifle? A wild guess says nearish 2000??

Anybody else had this problem?

It will be over 3 weeks until i can get back to the range for more testing. My gun has GREMLINS inside!

[Eric]

What happens when you try it with the BAD lever removed?

[aklaunch]

That is a great question!

I will find out next month and report.

I do not want to shot gun parts at it and never really know the exact problem.

I will test the buffer spring, test the gas rings, test a new BCG and try it with the B.A.D off systematically.

I love that B.A.D lever. The only issue i have had with it (so far) is that the bolt will not lock back with the 20 round Pmags. Easy fix for such a wonderful little device.

[John Moses]

Sounds like a Buffer spring issue. I would suggest a Springco Spring. Sometimes when the wrong buffer/spring is used, the ammo can really really make a difference when it may normally not cause this. I would also remove the spring and buffer and give it a good cleaning. The spring is designed to run dry, but I have improved reliability with cleaning the tube and spring, while "very lightly" coating the spring with fireclean, or KG1 . I have seen Mil-spec Buffer springs go bad/lose rate in as little as 3000 rounds. The Springco is the bee's knees!!!