Bryon said:
thanks all for the reply, what is the difference in accuracy between straight rifled and smooth? is it worth the year long wait?
I'd think long and hard before I decided on one. And then I'd decide against it. They have been around for along time, and even the people of the day never found them to offer any advantage.
In 1789 Cleator wrote:
"The straight rifling of barrels, is an expedient, which, though not often practiced, yet deserves notice, as having the testimony of some amateurs to its efficacy in preventing the scattering of shot. Neither the workmen who make these pieces, however, nor the persons who use them, can give any satisfactory explanation of the principles upon which the rifling proves serviceable in fowling pieces; and some of them admit that it cannot be of any use, unless the depth and breadth of the channels, and the size of the shot, are suited to each other. Having never tried any of these pieces, we shall not assert, that they possess no advantage over the plain ones; but we can safely say that they are attended with several obvious inconveniencies, the chief of which is, their great weight; for the barrel must be made considerably thicker than a plain one, in order to admit of being rifled, and the additional quantity of metal in it, when finished, will be in proportion to the depth of the channels, and the breadth of the threads. They are also more difficultly kept clean; and it is scarcely possible to prevent considerable windage, let us use what kind of wadding we will: so that not only a part of the force of the explosion will be lost, but the flame, by getting among the grains of the shot, will increase their divergency from its lateral expansion when the charge has quitted the muzzle. We shall, however, postpone the further consideration of this matter, until we have treated of rifle barrels in particular, when it will be better understood, and more in its proper place."
And later, after having discussed barrels with spiral rifling:
"The spiral rifled barrels, however, have entirely superseded the straight rifled ones, because although the latter prevented the rolling motion of the ball that takes place in a plain barrel, yet they do not communicate any other motion, that could serve to correct the variations that may occur during the flight."
And:
"Having now fully explained the principles upon which rifle barrels produce their effects, our readers will be prepared to consider how far the straight rifling can be useful when employed for shot. These pieces are said to be very common in Germany, and are used by a few persons in this country; though we understand that the greater number even of these few are now less partial to them than they were at first."
It seems they were mostly used for shot, as in this ad from Philadelphia, 1774:
"THO: PALMER Gun Smith... He likewise makes all Sorts of SHOT GUNS, such as straight Rifles, Cocking pieces, Fuzees, &c. in the best and neatest Manner,"
Spence