Yep, before you drop the mag, look to make sure that the bolt catch is in front of the bolt face, and not just under the carrier instead.


If the bolt is not in front of the bolt face, then suspect some sort of binding going on that is not allowing the bolt to come all the way back,

Hence pull all the way back on the charging handle, and confirm that the face of the bolt come back to about 1/8" to 1/4/ in front of the back edge of the ejection port window, and during the CH pull, the tension needed to pull back on the CH to get the bolt all the way back does not increase from about half way back, to all the way back (hence did not use a full lenght spring in a telescoping receiver extension, and the spring is coiling binding out before the end of the buffer and reach the end of the tube).

Next, shotgun the upper open, and insert a empty mag.  The bolt catch should be fully raised via the empty mag follower.  If the catch is not fully raising all the way up, then first confirm that the catch is not binding in the upper receiver slot, and when you did install the catch spring and buffer, you did clean out the bottom of the spring channel in the lower receiver of any debris.


Lastly, the normal ejection distance for a spent case should be 10' to 15' out of the ejection port.  If your rig is just dribbling out the spent cases, then suspect problems like a leak in the gas port,some other binding going on, or even too heavy of a buffer for the rounds being used.

Receiver extension (should be a depth void of 7") should use a carbine buffer, and 10.5" recoil spring.