. ▁These ▁rif les ▁are ▁incred ibly ▁rare ▁and ▁few ▁examples ▁have ▁been ▁documented . ▁They ▁are ▁configured ▁with ▁a ▁pol ished ▁check ered ▁stock ▁with ▁a ▁rol lo ver ▁che ek ▁piece ▁and ▁side ▁mount . ▁ ▁Argent in ian ▁modification ▁ ▁Con tr ary ▁to ▁some ▁spec ulation ▁F N ▁did ▁not ▁contract ▁or ▁produce ▁the ▁Argent ine ▁conversion ▁of ▁S AF N ▁ 1 9 4 9 ▁rif les ▁from ▁ 7 . 6 5 × 5 3 mm ▁Argent ine ▁to ▁ 7 . 6 2 × 5 1 mm ▁NAT O . ▁While ▁F N ▁did ▁receive ▁and ▁then ▁later ▁deliver ▁an ▁order ▁for ▁a ▁conversion ▁of ▁a ▁single ▁rif le ▁in ▁March ▁ 1 9 6 7 ▁the ▁remaining ▁arm ory ▁stock ▁of ▁the ▁Argent ine ▁rif les ▁were ▁converted ▁dom est ically ▁by ▁Metal ú rg ica ▁Centro ▁a ▁company ▁formerly ▁known ▁as ▁F á br ica ▁de ▁arm as ▁Hal c ón . ▁Metal ú rg ica ▁Centro ▁provided ▁and ▁installed ▁in ▁each ▁rif le ▁a ▁new ▁bar rel ▁in ▁ 7 . 6 2 × 5 1 mm ▁NAT O , ▁modified ▁each ▁e ject or , ▁and ▁modified ▁each ▁trigger ▁guard ▁to ▁take ▁a ▁new ▁ 2 0 ▁round ▁det ach able ▁box ▁magazine . ▁The ▁converted ▁rif les ▁were ▁provided ▁with ▁propriet ary ▁ 2 0 ▁round ▁det ach able ▁box ▁mag az ines ▁manufact ured ▁by ▁Metal ú rg ica ▁Centro ▁to ▁fit ▁the ▁S AF N ▁ 1 9 4