You won't know for sure until you use the DPMS magazine.
Clean the rifle again before you go back to the range and just before you go, maybe the day before break the rifle down, pull and clean the BCG a piece at a time check the ejector, extractor . Pull the buffer and spring, checking for burrs and wear. and when you go back lube liberly to point of wetting as you reassemble the parts, also swab the inside of the upper (except the chamber and bore!) with Mobil 1 synthetic motor oil. and go to the range with the DPMS magazine.