All bullets count of course and actually fire.
Try turning off tracers in the aircraft XDP and try it. We do have it, so some can pass through and cause no real damage in effect. That is how it was. It was even hard to spot some holes in real life, especially in flight. Only when landed would your mech go and find them and poke with stick
and point them out for you.
Re skin changed textures not always showing ... I have seen Windows 8 onwards cause issues when you alter a file and save it over a current one repeatedly. Windows 10 as the worst. Seen it many times when testing the randomised damage we do - files get copied in , you open them in Windows explorer and it shows you all the old ones with old thumbnails too. Seen that many times.