I picked A box of this Swiss made ammo to try. Other calibers of this brand I've fired have been great. I loaded a mag of it in my 20" AR and it short cycled And FTF'd for 5 rounds. I dropped the mag, stuck it in my 20 year old carbine and it ran like a dream with great accuracy. It's the first malfunction of any ammo in this rifle, including a couple thousand of my handloads. Has anyone tried this stuff in a 20" AR ?