Just picked up my new .223 and decided to treat myself to a new mod while I was at it - the reasoning being its got a 25" barrel and is way off balance with the weight of the P8 on the end. Went to zero it and the first shot took me by suprise - a LOT louder than the P8.... second shot made me jump as something fizzed past my head! Riccochet maybe? surely not as the target is against a back of soft earth. Third shot was louder still and I realised where the problem was as gasses poured out the bush of the mod.
Removed the mod and a petal of metal the width of the barrel fluting had peeled off the reflex tube and obviously flown out the gap between the rear buch and the fluting. Makes you shudder.
Gunsmith was very good about it, replacing it with a different model free of charge.