Yes, the DoubleStar ARFX with Buffer Tube with Black Foam will replace the rifle length buffer tube on your Aero Precision M5.
This DoubleStar ARFX with Buffer Tube with Black Foam is a rifle length buffer tube. It is 10" in length. It comes with the ARFX Stock , A-2 Buffer Tube, Foam Overtube and Butt Pad and All needed mounting Hardware. A buffer and spring is not included.
The DoubleStar ARFX Comes with ARFX Stock , A-2 Buffer Tube, Foam Overtube and Butt Pad and All needed mounting Hardware. You will need a rifle length buffer and buffer spring.
I recommend using the JP Enterprises Tuned And Polished Buffer Spring at the first link below and the Luth-AR 308 Buffer Body at the second link below.
https://www.opticsplanet.com/jp-enterprises-308-tuned-and-polished-buffer-spring.html
https://www.opticsplanet.com/luth-ar-308-buffer-body.html
Yes, the DoubleStar ARFX Skeleton Stock w/Buffer Tube has an A2 style buffer tube.
Yes, this will work with commercial thread pitch.
Length is 10"
No it does not.
No, it does not.
It is built in to the stock. An end plate is not required