Sendra huh? well sendra was a manufacturer in the early 80's, i belive that they and colt at one point were the only companyies manufacturing ar-15's for the public. i had one and it ran great, never had any problem with it but i heard there wre some with there troubles, i recently just sold it to fund antoher ar-15. A friend of mine was a good friend of the the owner of the company and bought the first few that came out he had serial numbers 100- 111. He gave me the upper a couple years ago because he was cleaning out his safe and didnt think that this was one of the good upper and that i could just use it as parts, well he was wrong the thing shot great. a few months after that he sold me a spare lower with an ace socom stock and a chip McCormick trigger in it for 150, so i had a whole ar-15 for $150 dollars
talk about a dreal and a great gun