Have you tried shooting it out of the prone using those 40 round mags yet?
Seems a concern I remember was the bottom of the mags digging into the dirt when you’re trying to stay nice and low in the prone… something about “teeter-tottering”… best to find out these things now before it’s Run What You Brung time…
Congratulations on the purchase.
The wicked flee when none pursueth..." - Proverbs 28:1