Yesterday at a GSSF match I had a RSO tell me that Plated bullets will keyhole (tumble) when shot in a Glock barrel. This is more apparent at longer ranges - say 25 yards. The conversation started when scoring one of my 5 to Glock strings and one hole was slightly out of round at the 25 yd target. This was with my G26. I have not heard of this before and after shooting thousands of rounds of plated 124 gr bullets I'm a little surprised. However there is always something new to learn so I thought I'd ask the members of this forum for their comments/input.