" P-mag still seems functional " Yea - like a car with the windshield missing...it may function, but isn't safe or recommended.
Seriously, I was searching for 'catastrophic AR failures' and came across this - on July 27th, 2020 I was at a range where the man two positions to my right had a catastrophic failure. He was firing a SBR AR-15 (with an extremely obnoxious muzzle device which send shock waves five shooting positions either side of him) and had his magazine blow out, sending pieces of plastic and unfired rounds in every direction. Fortunately he was uninjured, just shaken.
The Range Safety Officer immediately shut down the range and checked the firearm. I overheard the conversation between the RSO and shooter and supposedly the the BCG was partially open (perhaps 6mm), but the BCG was locked-up and wouldn't move further. There RSO said he didn't see any indication of barrel bulging and the magwell was intact. I didn't take a closer look, but could see 'smoke' coming out of the action indicating the chamber was exposed. I don't know if he was firing when this took place or it occurred as he released the BCG.
Needless to say that was the end of the shooter's range time and he left soon after. Thinking back I can't recall if the report was louder than normal because his muzzle brake was so darned loud. Later when we were collecting our brass we found a blown case and primer near where he was shooting, but
if it came from him if would have been a previously fired round and I didn't look at the head stamp - I also didn't ask if he was shooting factory loads or reloaded ammunition..
My 17 year-old grandson and I just built a .223 Wylde AR-15 with a 20" heavy barrel and a 3-9x40 Sig Sauer scope in June, 2020 and we were SO meticulous in our build since it was the first for both of us - we checked head space with 'GO/NO-GO' gauges and made sure everything was OK - it shoots fine and is accurate (better than I am), so our care paid off.
This is at 100 yards - still have some tweaking to do on the scope.