When you say allow for a 30rd mag, you are meaning it will be high enough to clear the mag from the ground? If so, yes, on the lowest setting you clear a 30 round mag. The legs adjust much higher also.
https://farm2.staticflickr.com/1799/...d922e99c_c.jpg
One thing I probably didn't read in the product description is that the legs don't go to 45 degrees. So only 90. So for me, on a few bolt guns, prone is going to be much higher then I would like it to be. Wonder if I can make my own notch in the leg to make it 45 capable... Man.. so close.. but that lowest available / capable height may be a deal breaker. But on an AR.. it's a good height for 30 round mag.