Martin - here is the earliest example of the term I have found, and it may interest you in particular as it notes a situation in Lancaster County:
Collection: The Pennsylvania Gazette
Publication: The Pennsylvania Gazette
Date: September 20, 1739
Title: RUN away on the 6th Inst. from Thomas Rees, of Heydelburg To
RUN away on the 6th Inst. from Thomas Rees, of Heydelburg Township, Lancaster County, a Servant Lad, named Richard Beddes, aged about 17 Years, has light bushy Hair: Had on an old striped linsey Jacket, old linnen Shirt, new Linnen Breeches and an old Hat, no Shoes nor Stockings. Took with him a smooth Rifle Gun. Whoever brings the said Servant to his said Master, or secures him in the County Goal, so that he may be had again, shall have Three Pounds Reward and reasonable Charges, paid by Thomas Rees.
Here's one from Northampton County:
Collection: The Pennsylvania Gazette
Publication: The Pennsylvania Gazette
Date: January 26, 1769
Title: RUN away from his bail, on the 9th of this inst. January, JOHN
RUN away from his bail, on the 9th of this inst. January, JOHN DAVIS, this country born, about 21 years of age, about 5 feet 5 inches high, of a sandy complexion, freckled, had a pretty large scar on the instep of one of his feet, occasioned by the cut of an ax, and he is pretty talkative; had on, when he went away, a blue broadcloth coat, with mohair buttons, a red plush waistcoat, leather breeches, and a fine hat; he also had other clothes, of a light ash colour, lined with striped linsey, the coat had no lining in the sleeves; these he had packed up in a pair of check trowsers; he may dispose of one suit; he took with him a smooth rifle gun, and as he has served his time, he may possibly produce his indenture. Whoever secures the said runaway in any goal, shall have FIVE POUNDS reward, paid by the subscriber in Forks township, Northampton county. GEORGE TIDFORD.
German imports, both rifled barrels and smooth rifles:
Collection: The Pennsylvania Gazette
Publication: The Pennsylvania Gazette
Date: February 17, 1773
Title: Philadelphia, February 15, 1773.
Philadelphia, February 15, 1773. To be SOLD very cheap, for cash only, by CONRAD BATIS, Living in Market street, next door to the corner of Third street, opposite to the goal, in Philadelphia, A QUANTITY of this country and German made RIFLES , both cut and smooth bores, in the best manner; also a quantity of German made GUNS and PISTOLS, likewise gun mountings, barrels and locks, a quantity of violins and violin strings; a reasonable abatement will be made to such as buy a quantity to sell again, of any of the aforesaid articles.
N.B. The said Conrad Batis pays ready money for clean LINEN RAGS.
Maryland:
Collection: The Pennsylvania Gazette
Publication: The Pennsylvania Gazette
Date: May 3, 1775
Title: TWENTY ONE POUNDS Reward.
TWENTY ONE POUNDS Reward. RUN away, last night, from the subscriber, living near Bush river, Harford county, Maryland, 7 English servant men, viz. John Brown, about 35 years of age, about 5 feet 8 inches high, has black hair, large temples, narrow chin and thick lips, used to the sea, and a great swearer. N.B. Has been in the country before. Abraham Peters, about 28 years of age, about 5 feet 9 inches high, has black hair and beard, of a swarthy complexion, his left hand somewhat perished and lame; says he is a Jew, and talks very good Dutch. John Cooley, about 22 years of age, by trade a Plaisterer, about 5 feet 8 inches high, round face and well set; had on a blue fearnought jacket, and a double breasted under jacket, white yarn stockings, and old shoes. William Childs, about 21 years of age, about 5 feet 6 inches high, a Carver and Gilder by trade, and but meanly dressed, which was a blue fearnought jacket, and old shoes, with hob nails. Thomas Able, about 25 years of age, about 5 feet 5 inches high, has a remarkable red face, very rotten teeth, is a great talker and very much pitted with the smallpox; he has been in South Carolina before. William Blancklett, about 27 years of age, about 5 feet 4 inches high, thin visage, sharp nose, black hair and beard. Thomas Sharp, about 15 years of age, about 5 feet 3 inches high, fair complexion; he had on a green coat, blue cuffs; stole and took with him two pair of trowsers, one striped holland and the other ozenbrigs, one white shirt and one check ditto, new felt hat: As Able and Blancklettbreeches were much worn, it is imagined they wear said trowsers. They had and took away with them a country square barrelled, smooth bore GUN, rifle stocked, one pistol, and other firearms; it is supposed they stole a BOAT from Otter Point. Whoever takes up the said servants, shall have, if taken 10 miles from home, Ten Pounds; if out of the county, Fourteen Pounds; and if out of the province, the above reward, or in proportion for each, including what the law allows, paid by BUCKLER BOND,
WILLIAM SMITHSON.
*** It is like they will make for some vessel, therefore all masters of vessels, and others, are hereby forewarned from taking said servants, at their peril.
March 26, 1775.