The Jacob’s Rifle

by Fred Ray on August 19, 2006 · 6 comments

Brigadier-General John Jacob

One of the more unusual sharpshooter rifles was the Jacob’s, the brainchild of John Jacob, one of those brilliant, eccentric British Army officers who spent his career in India.

He had spent 25 years improving rifled firearms, carrying on experiments unrivalled even by public bodies. A range of 200 yards sufficed in cantonments, but at Jacobabad he had to go into the desert to set up butts at a range of 2000 yards. He went for a four grooved rifle and had numerous experimenal guns manufactured in London by the leading gunsmiths and completely at his expense.

Jacob, like Joseph Whitworth, was renowned not only as a soldier but as a mathematician, and his rifle was as uncoventional as its designer. Rather than using a small .45 caliber bore Jacob stayed with more conventional .57-58 caliber (Bill Adams theorizes that this would allow use of standard service ammo in a pinch). In any case his rifle used four deep grooves and a conical bullet with corresponding lugs. Though unusual the Jacob’s rifle, precision made in London by master gunsmiths like George Daw, quickly gained a reputation for accuracy at extended ranges. They appealed in in particular to wealthy aristocratic scientists like Lord Kelvin, who swore by his. Jacob wanted to build a cannon on the same pattern, but died early at age 45.

pair of Jacobs 3.jpg

Single barrel Jacobs muzzles.jpg

The Jacob’s came in both single and double versions, as shown here. (Photos by Bill Adams)

Jacobs full viewDB.jpg


Only a few Jacob’s were used during the American Civil War, and those were privately owned, usually by men able to afford the best. I do have one account of one of Berdan’s men using one (the chaplain, Lorenzo Barber), who kept one barrel of his double rifle loaded with buckshot and the other with ball.

Next — an explosive proposition!

UPDATE: Kenneth Jacob, whose web site I linked to above, tells me that Jacob’s proper title was brigadier-general, not brigadier as would be the case today. I have changed the caption to reflect this.

UPDATE 12/16/20: I have a new post up revising the statement about Lorenzo Barber’s use of a Jacob. I now think it was something else.

{ 3 comments… read them below or add one }

Robert Whittington October 17, 2009 at 12:29 am

I own a double barrel Jacobs and sword bayonet that came with it. The scabbard I had made only to protect the bayonet. Also, have two 1800 coins which are with the rifle which were used to cut template patches….Very rare rifle and in very good condition. Used by my Great-Great Great grandfather Issac Clayborn in the CSA.


jack scott May 13, 2020 at 5:56 am

hello I have a s.barrel Jacobs inscribed colonel john Jacobs army rifle made by reilly of London barrel length 31 in long inc tang single leaf rear sight graduated to 100 to 1000 yds spring retained barrel bands swelled rammer with deeply recessed underside of barrel stamped with crowned view and proof marks roller rammer retaining spring stamped e.hollis Birmingham overall rifle in excellent condition very good shooting condition bore I myself have put few rounds thro it but I am just a grand father best of luck with your rifle hope you enjoy it all the best jack


Jeremy December 9, 2020 at 4:06 pm

Hello, I’m doing research on Lorenzo Barber of the 2nd USSS. What was the account of Barber using the double barreled rifle and would you be willing to share the source of said account? Thanks.


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