is it possible to change the a2 buttstock to an a1 buttstock to shorten the length jsut enough for shorter people ? is the buffer tube on the lar8 a2 an actual full length a2 tube? or is it an a1 tube with a2 spacer that could be removed and slide an a1 buttstock on it? reason, l.o.p. would be easier since i am shorter for cmp off hand , more accustomed to shooter 223 a2 right up behind the rear sight off hand..