BangBang
Professional
He says he hasn’t fired it, so I doubt it's the gas block...but the rest is solid advice.
And I’m gonna add something, here (not aimed at you, @BangBang ; more just a general observation)...
I NEVER use live rounds for non-firing function checks. This is precisely what dummy rounds are designed for.
Jacking live rounds into/out of your chamber is a one-way ticket to a UD (Unintended Discharge—covers both negligent and “accident”)...maybe not this time, but some time down the road.
Additionally, it prevents damaging live ammo which, right now, is a very precious commodity.
Amazon.com : Magpul 223 Dummy Rounds (Pack of 5) : Sports & Outdoors
Amazon.com : Magpul 223 Dummy Rounds (Pack of 5) : Sports & Outdoorswww.amazon.com
$6.09 is mighty cheap insurance to prevent it...and they really aren’t that much more expensive than live rounds right now, anyway.
Sorry, I didn’t realize he hasn’t fired the weapon appreciate it. Also good point on the love round. I have read many times folks running rods down the barrel to force a round out.