if someone can't understand simple things first time, it's can be mistake, but if he can't understand and second time - this just stupidity...
so, i think no any reasons for continue of this "constructive discussion"...
for all - PLEASE, don't post stupid things here, and if you want read about forsazh of m-82FN (early and late variants), go to here -
page 10 of "Рождение Ла-5 или ..." and next pages...