Hi all. Just another FNG here with some questions. Pardon my ignorance and stupid questions. I just got A M21. This is my second Springfield. The first was a Squad Scout. I missed it and was so impressed with the performance I decided to to find another. The M21 was not my first choice but could not find anything else. Not sure what I got for all that extra $$$$$. Also want to put a U.S. Optics scope on it. I was looking at the Troy Battle Rail or the Airbourne mount. Any feedback would be great. Thanks in advance.