Sorry gents but the smoothrifle is no abbreviation but is rather a factual part of history.
Passages from guns of the American West
The "two-sighted smooth-bore rifle" - shoulder arm of heavy octagonal or 1/2 octgonal barrel equipped with both front and rear sights. The advantage is given in slight range extension of 20 to 25yards over the smoothbore shotgun or musket, handled shot equally and being heavier made, could withstand much tougher use than the normal smoothbores.
Passages from the PA Gazette
The Pennsylvania Gazette
September 20, 1739
Had on an old striped Jacket, old linnen Shirt, new Linnen Breeches and an old Hat, no Shoes nor Stockings. Took with him a smooth Rifle Gun.
The Pennsylvania Gazette
January 26, 1769
...he took with him a smooth rifle gun, and as he has served his time, he may possibly produce his indenture.
Just a few examples I had readily available.
:thumbsup: