[Tacky]

Sometimes the dust cover not latching closed has to do with the detent and spring on the ejection port cover, seen that a few times. If that was my rifle, I shoot it, and enjoy it.

I was thinking about it, is it possible that since ruger is making several calibers on the ar556 platform that require larger ports like the 450 bushmaster, or 350 legend that they are making all the uppers with wider ports to save money since it doesn't effect function? The 450 requires a bigger opening to allow proper ejection. Just a thought. Or if they aren't it could be that a 450 opened upper receiver made its way on to a 5.56 rifles, very hard to tell the difference unless you use a micrometer on it to double check.

However either way it won't effect its function. Run the bolt carrier literally wet with lube for a couple hundred rounds until it breaks in. Thats how I run mine, the whole battalion of them.

 

[Tacky]

Yep...I bought this one as a beater/truck gun, not worried much about cosmetics on this one (or any of mine actually ). I've put about 500 rounds through it so far, zero issues...that matters more than a functioning dust cover to me.

Great to hear it, I have a few that are reserved for personal defense carbines that are not treated as some of my other ones like my national match and precision rifles, so I know where your coming from.

You know another thought is that is ruger still putting plastic ejection port covers on the ar556? That could be a possible issue too, the original metal is far better, and fit is better, could easily swap it, just becareful not to loose the retaining ring on the ejection port rod. As many as I have done I have still lost those dang little rings, and have a pack of spares just in case. An o-ring tool and needle nose pliers are very useful messing with them. Just a heads up. You can swap the cover without removing the barrel from the upper receiver, just tedious.

 

[Tacky]

The original dust cover on mine was metal.

Thats good, I think I remember them or one manufacturer using plastic epc's, which I did not care for. Plastic that close to the bcg and the heat it generates cannot be a good combination in my opinion. Perfer the metal as original they were built by stoner, however the upper without the epc like the dpms are totally fine too. Own a 5.56 and 308 win dpms smooth side, no epc, no issues.