We received a copy of a letter from the ATF’s Firearms Technology Branch concerning the use of arm braces on AR pistols that referenced the Sig Sauer SB15 pistol stabilizing brace specifically.
The ATF’s letter says that they’ve determined that firing a pistol from the shoulder would not cause the pistol to be reclassified as an SBR.
The letter, signed by the Chief of the ATF’s Firearms Technology Branch, Earl Griffith, states, “the firing of a weapon from a particular position, such as placing the receiver extension of an AR-15 type pistol on the user’s shoulder, does not change the classification of a weapon.”
“Further,” wrote Griffith, “certain firearm accessories such as the SIG Stability Brace have not been classified by FTB as shoulder stocks and, therefore, using the brace improperly does not constitute a design change.”
This clears up any doubts that firing an AR pistol using the distinctly buttstock-looking SB15 could get you in trouble, even if fired while shouldered.
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