https://dsgarms.com/lower-receiver-parts-armea1108-a

How tight is the mag catch in the lower receiver channel for it, and is the catch tab on the catch that locks into the mag, flush with the top surface of the flat section is comes off?

As for mag well, should not have to pull the mag downward hard to get it out one the catch releases the mag, but on the other hand, should not be like a BB in a Box car with the well too wide for the mag isntead.

Hence could be that the slot for the catch is too big since it should almost be key like fit, the top of catch tab should be flush with the top of the rest of catch, the mag catch threaded end should be flush with the face of the button, the well just machined way too over size,  or could be that the catch channel for the catch assembly is too low in the lower receiver instead.


Pull a mag down to just the body, pull the mag catch assembly off the rig, and with the bolt locked home, shove the mag all the way up into the well until the body lips are tight against the bottom of the carrier, then look into the mag catch slot to see where the mags side slot is to the mag channel bottom edge.
At most, the bottom of mag/s side slot for the catch to lock in,  should only be about 1/8" above the bottom of receiver slot edge, while the norm is to have the bottom of mags side slot bottom edge about 1/16" up from the bottom of receiver slot when the feed lips are tight against the bottom of the carrier. Hence with the mag locked into the catch, the lips of the mag should be about 1/16" below the bottom of carrier.
Note, top of mag side slot should be about 1/8" above the  top of the receivers channel at the same time when the bodies feed lips are tight against the bottom of the carrier.


The other one to check, look up the front inner wall of the mag well, and make sure that the upper receiver front wall is not protruding back over the top of well wall edge. When this happens, the front of the mag will catch the upper receiver edge on the load, causing the mag to tilt like hell in the well (if you can get the mag to lock in place).