AR15 trigger reset problem

[matt33]

At the range yesterday, my Colt MT6721 with JP Trigger failed to reset 4 times in a row during my shooting session. The failures came on fired rounds #12,13,14, and 15. I broke the weapon down each time and checked for any obvious problems. Finding nothing each time, I put the weapon back together and fired again. Each time, my AR cycled normally, but the trigger failed to reset.

As mentioned, this happened 4 times in a row. The trigger always reset normally when I cycled the action manually. The trigger was installed by a reputable gunsmith about two years ago. Since that time, I have never had a problem with any of the 1000 or so rounds I have fired.

When I got home, I broke the gun down any sprayed the heck out of the trigger group with aerosol Gun Scrubber and reapplied Miltec oil. The rifles seemed to pass all function checks, but it never failed any of them at the range either (except for live firing).

This is my primary rifle. I am concerned about its reliability. Any advice would be greatly appreciated. Thanks.

 

[dfariswheel]

Problems like these are often caused by "wear-in". That is, as the trigger is used, it wears, (like all mechanical devices).

Possibly what happened is, the gunsmith set the trigger very close to "the edge" to give you the best possible trigger, and now that normal wear has taken place, the trigger is now OVER "the edge", and is now malfunctioning.

Since you've cleaned the trigger assembly, there's little chance of fouling or some foreign matter interfering with the action of the trigger.

Best suggestion: Have your gunsmith re-adjust the trigger for proper operation, and possibly NOT set it too close.

Often, on a "primary rifle" you have to choose between having a totally reliable rifle, or a rifle with the best possible target-grade trigger.

The target-grade trigger is nice, but NOT when it's not reliable.

In other words, when all you're shooting is targets, you can sacrifice some reliability to improve accuracy. When you're trusting your like to it, reliability is King.
You don't use a target gun to defend your life, unless you have NO choice.

 

[Chris Rhines]

Most likely, your trigger takeup adjustment screw has worked itself out too far. Take the takeup screw out and throw it away. Adjustment screws don't do well on fighting rifles.

- Chris