Brand new AR-15 troubles

Four years ago I bought a CMMG AR-15 at an auction. The auctioneer said it was brand new, never fired, but had no papers or a box. I bought it cheap and it went into my son?s safe. It looked good and I bought it cheap.

Last weekend I mounted a red dot sight and took it on a try out. The rifle shot good, zeroed out it was going fine and functioning flawlessly. I wanted to switch from factory green tips (SS-109 NATO) to reloads I pulled the magazine tried to eject a live round. No way!!! It was stuck. Beating the charging handle with a boot heel finally did the trick. I cycled another round into the chamber and it fired and ejected but the following round could not be cycled by using the charger handle.

The chamber looks fine and I am stumped. A fired round ejects normally. A unfired round that is chambered by a fired round cannot be cycled. A manually chambered round is difficult but one chambered by firing a round has to be beat.

I?m guessing polishing the chamber might help. Any more guesses out there?

If I'm reading you correctly the gun fires OK and ejects every time but if a round is chambered and not fired it can not be ejected manually? If that is the situation I would look to see if the "factory" bullets have been seated deep enough into the case. There might be inconsistency too or they may not be crimped hard enough and are backing out during recoil.

Overall, your barrel may be not have enough "lead" between the chamber and where the rifling begins. In other words the bullet may be touching/sticking/jammed against the rifling. Once fired it doesn't matter--the bullet is gone and then the case ejects normally.

At this point I would guess the chamber is OK since it loads but polishing wouldn't hurt. A good check would be inserting an empty case (preferably sized) to see if the same problem occurred.

It will be interesting to see how the reloads and rounds from other manf function.

My 2 cents

if the issues are with the reloads, then the reloads are to blame, or the reloader,,

FL sized brass? should work fine, but some are better doing Small Base dies,

if you did the reloading, get , if you don't have, a Wilson, or Dillon etc case gauge, and drop a few of the factory green tips in, and they will like fall right back out when you turn it over,
the reloads should too if they were done correctly,

The only ammo fired was factory made green tipped SS-109. NO RELOADS WERE USED.

your post mentions reloads,

so it was not ejecting any of the SS109 green tips? (that were not fired?)

It would eject a fired round but you could not not extract a unfired round using the charging handle.

clean the chamber, well,

polishing will not likely make a difference

I am so hammered by an accident I do not have a clue when I will be able to get on the range. I?ll try several different ammo and I think every thing will loose up. Thanks for the help.

well now try to take care RED,

check the ammo with a case gage and a micrometer.
I had some factory loads that were .001 OVERSIZE on 45 ACP rounds. I ran them through the bullet crimper and they worked fine after that. I did get a return authorization to return the rest of them. That was a mistake because I had to drive like 50 miles one way where a UPS corporate office would handle it. I should have just crimped em all and shot em up. Kind of pissed me off, it was a BIG NAME brand of ammo too and they just sent me the same quantity back not even an extra box of 50. Surprised me really