If you are like me, you remember seeing the Sig SB15 a while back and thinking “hey they hacked the NFA”. Of course we all know how it is supposed to be used, but let us get real and look at this objectively: Sig made an “arm brace” and got ATF approval for said arm brace. The arm brace slides over a pistol buffer and looks like a stock… but it is an arm brace. Well, regardless the internet is abuzz with the legality of using the brace as a shoulder stock and whether or not you would suddenly be in violation of the law, but I sure as heck am not writing the ATF’s Firearm Technology Branch to ruin it for everyone. Anyways, instead of risking breaking the law I asked my friend CJ if we could put a pistol buffer on his registered AR15 SBR (this explains the foregrip as well) and test this thing out by using it as both an arm brace and a stock. So here goes.
Installing the SB15 is incredibly easy, as it slips right onto a pistol buffer and if so desired you may use the Velcro straps to cinch it up to your arm.
I must admit that with this thing on my arm made me feel a bit like Megaman, and when firing it the recoil feels… funky. I really do not know how to describe it but the recoil impulse seems to run up and down your arm.
Regardless of the strap though it just did not feel quite right. You really need to turn the gun sideways to aim it right and it does not relieve much weight. It is quite difficult to hold steady as well, and even my buddy CJ agreed (and he is a much bigger man than I).
Either way we both agreed that this rig was incredibly uncomfortable and at the very least impractical as can be. You see, I have shot AR pistols with the padded buffer on my cheek and my off hand on the forend and I find this to be more comfortable than Sig’s awkward arm brace. It is also inaccurate. Here I was aiming for the spot on this target where the bottom of the top rectangle meets the top of the diamond from about 10 yards away:
So yeah, that’s that but lets get real and see how well this bad boy functions as a shoulder stock. The answer to that is quite well, and this gun being an SBR I am sure that I was well within the confines of the law!
First and foremost I got rid of the straps albeit I suppose you do not have to do this. Also for giggles we put on an SAS Arbiter suppressor.
The rubber the brace is made of is very comfortable and is almost like having a giant recoil pad on the back of your gun.
So all in all, I would say that at Sig’s price of $140 before shipping/taxes you would be better off paying a little extra to just SBR your gun (unless your state or country prohibits such a thing). But nonetheless the Sig SB15 is an expensive solution to a problem that I was not aware existed.