Allen & Wheelock" Army "Centerfire" Revolver, six-shot, .44 caliber, single action. 19 cm round, rifled barrel with remnants of patents on the right side "ALLEN & WHEELOCK WORCESTER. MASS. U. / ALLEN'S PT'S JAN. 13 DEC. 15, 1857 SEPT. 7. ». Closed frame and barrel plain. Opening trigger guard for the use of the extractor rod. Waxed walnut stock plates. Length: 34 cm B.E. (wear of use). Numbered 247 on the ramrod release key and the barrel. Manufactured from 1861 to 1862 and produced at 700 pieces approximately. The US government purchased 536 in 1861.