As the title implied, don't try to put a lightweight trigger with short reset and short pull in your 10mm AR's.

I had initially installed a straight trigger Chip McCormick trigger in my build while waiting for a heavier trigger to come in the mail and that was a mistake.

The short reset/short light pull trigger bump fired far too easily and took me by surprise.  Considering that I was shooting on a wobbly table, was probably the result of a perfect storm of coincidences.  But was unexpected nonetheless.

It fired so fast that I flinched and afterwards was surprised that I didn't suffer an OOB discharge, but thankfully that didn't occur too.

So, I immediately stopped, removed the trigger out of the gun until the replacement arrived.

I ultimately ended up using a Rise LE145 trigger and it's doing great.  I shot it a lot today and was unable to recreate it despite doing everything the exact same as before.  Same ammo, same table, and all.

No more surprise bump fires.  Accurate enough for hunting. 

I zero'd the optic today and had several touching at 25 yards where I typically zero my pistol caliber builds.  My son walked back to about 65 yards and was able to ring the steel target 3 out of 3 times off hand before having to pack up from all the rain we've had the last few days.

So, just wanting to give a PSA for anyone that cares and is wondering which trigger to use in their build.  While I'm not shilling for Rise Armament, I more specifically wanted to warn against NOT using one too light and too short of reset because I had problems with it.

After looking around online, I'm not the only person who reports similar occurrences using really light triggers in these.  I'm just trying to share a suggestion to prevent that from happening to anyone else unexpectedly.

I worked on a 9mm PCC with the same issue.   It was a cheap brand and trigger group and worked for approx 1.5 yrs until the trigger group wore in/out and it turned into a full auto even with cheap FMJ 9mm rangevammo. Changing buffer weights, springs etc did not prevent the bump fire.
  Spent $69 and put a BCM PNT mil-spec in it with no other changes and my customer said it is running good after several hundred rounds and about 6 months of time.  When I installed the PNT trigger my trigger pull gauge said it was right at 6# 3oz and pretty crisp.
  The OEM trigger weighed in at 5# 7oz but it would bump fire almost on demand regardless of loose or very tight hold.

Be very careful of all that reciprocating weight in these PCC guns!

Steve

Thanks for the reply.

I haven't had any more trouble with mine either.  I hadn't intended to keep the chip mccormick trigger in the gun anyway and was just there so I could test the build and get a few shots downrange while I was waiting on the other trigger, but I wasn't expecting that to happen either.  I've never experienced that in any of my other builds.  Though, in fairness, I don't generally use very lightweight triggers in my builds, unless they're my match rifles, which PCC's obviously aren't.