I have a DPMS AR-15.  I got it off-the-rack, already assembled, nothing custom.

I put enough oil in it that it was leaking out of the cracks.  I put a few hundred rounds thru it at the local range and then took it to a four day course at Frontsight, NV.

At the local range it would sometimes fail to grab a new round - click no bang.  This was most noticeable with steel, thirty round, banana mags.  So at Frontsight I used only twenty round plastic mags.  I got a few malfunctions.  The last half of day four - test time - we got hit by a sand storm.

So I got home with a very dirty gun.  I broke it down and submerged everything in solvent.  I then went to the local range.  Every shot was single shot, never chambered a new round regardless of the magazine. Then I remembered I had forgotten to oil it after cleaning.  The only oil I had with me was a gallon of synthetic diesel oil, and no way to be delicate in it's application; I just poured it in.  And several hundred rounds later had not had a malfunction regardless of magazine used.

That amount of oil does make it work but is not practical.  Should I be considering maybe some honing, or something else?

TY

Pick up some tw25b grease, it's good stuff. Your gun might have needed just a little break in period. Or it could be an indication of something else. Strip it down and look for any rough spots that might be causing extra friction to the BCG. If you don't see anything just keep shooting it. Most likely you had more malfunctions with the steel stuff because it is not as powerful. Was your bolt locking back on the last shot? It sounds more like your BCG isn't traveling fully rearward then a mag problem.

Bolt locking back or not on an empty mag will help diagnose the problem if it rears its ugly head again.

If it does its likely an extraction issue. If it doesnt you have a cycling issue (most likely gas)

I highly advise a BCM extractor upgrade kit in every rifle, no matter round count. (although the new spring + O-ring is usually too much tension, i dont install the O-rings).

I like CLP myself, but have been eyeing SLIP 2000 due to great reviews. Lube is very important.

I didn't see where you stated what type of ammo you were shooting.

Inexpensive low power steel (biggest offender), and brass economy ammo, combined with a new gun is probably the root of your trouble.

You need to fire at least 500 full power rounds (Lake City M193 or M855) to start the gun down to road to break-in.  Before that you should expect some stoppages.

Why is it not practical to run the rifle "wet"? Sounds like you're approaching a thousand rounds through it, so wear-in is behind you; you've verified it runs flawlessly with Rotella D (Or Delo) on it, so why change things?

HTH
GSM