The 20 round CPD/D mag is approximately 3 1/8 from the juncture of the mag well and trigger guard on my Anderson (Poverty Pony) lower. My seventeen round E-Lander are approximately 2 3/4 measuring the same way. A ten round E-Lander sticks below the edge of the mag well 3/4 and an ASC ten round sticks out 1 below the mag well.
There are pictures of the various 6.5 Grendel mags in the linked thread.
https://www.65grendel.com/forum/showthre...mag-review
There are pictures of the various 6.5 Grendel mags in the linked thread.
https://www.65grendel.com/forum/showthre...mag-review

