u/Few-Entertainer9339

New rifle! Cycles everything fine up until the last round and then this. ejects at 4-6 o’clock everything from sig 125 supers to subx 190s but the last round of the mag with Winchester white box and subx do this. Sig ammo functioned perfect as well as the rifleline fmjs. Out of a 16” barrel with an omega 300 on the end. I forgot my mags at home so I used a steel ASC 5 round mag I found in my truck. Any suggestions?