Hope this is the right place.
When I bought my r10 brand new from the shop, I also bought a spare mag,after prob a week or so plinking and setting up the gun how I liked in the garden, I went out and the first trip the spare mag jammed in the gun, was hells own job to remove without damage, (didn't want to end my night early)
Got it out, and it looked out of line, returned to the shop and he was going to send to bsa as he had heard about this problem before, that was a good few weeks back, so rang him to see if new mag had arrived, when he announced, it has not been sent back, rather b