ency ▁was ▁formed ▁in ▁ 2 0 0 3 , ▁the ▁side ar ms ▁issued ▁to ▁its ▁Ag ents ▁and ▁Offic ers ▁were ▁the ▁weapons ▁issued ▁by ▁the ▁legacy ▁ag encies : ▁the ▁U . S . ▁Custom s ▁Service ▁and ▁the ▁U . S . ▁Im m igration ▁and ▁Natural ization ▁Service . ▁ ▁The ▁US CS ▁issued ▁side arm ▁was ▁the ▁G lock ▁ 1 9 ▁ 9 mm ▁p istol . ▁ ▁The ▁I & NS ▁issued ▁side arm ▁was ▁the ▁He ck ler ▁& ▁Koch ▁US P ▁Comp act ▁. 4 0 ▁cal iber ▁p istol . ▁ ▁Both ▁p ist ols ▁were ▁loaded ▁with ▁h ollow - point ▁r ounds . ▁▁ ▁In ▁ 2 0 0 9 ▁the ▁ag ency ▁selected ▁the ▁S IG - S auer ▁P 2 2 9 ▁DA K ▁( double ▁action ▁K ell erman ) ▁. 4 0 ▁cal iber ▁p istol ▁as ▁its ▁ag ency ▁issued ▁side arm ▁loaded ▁with ▁h ollow - point ▁r ounds . ▁ ▁This ▁weapon ▁stayed ▁in ▁service ▁from ▁ 2 0 0 9 ▁to ▁ 2 0 2 0 . ▁ ▁Side ar ms ▁The ▁ag ency ' s ▁current ▁duty ▁side arm , ▁is ▁the ▁S IG ▁S auer ▁P 3 2 0 C ▁( C ▁for ▁Car ry ) ▁p istol , ▁chamber ed ▁in ▁ 9 × 1 9 mm ▁Par ab ell um ▁h ollow - point ▁r ounds , ▁util izing ▁a ▁stri ker - f ired ▁mechanism ▁in ▁lieu