I haven't had any issues so far with plain ol 115 gr 9mm FMJ. The mags are top load like a rifle mag and with the Shockwave Blade its easy to stabilize without planting the stock into the shoulder. KAK packages the Shockwave with a copy of the ATF det letter. I tried installing the Sig SB15 Brace first and it felt oversized and awkward. Shooting with my forearm threaded through is awkward and heavy. Shooting with cheek only is fine but the brace moves a little. The Shockwave Blade stays put and its cheaper than the SB15. My only complaint is that the adapter didn't come with set screws (had to get them from Home Depot for less than a buck *shrug*)