There is a simple method of choice of barrel: from muzzle part in a barrel insert the bullet of ball-cartridge and with force "twistit" there.
There is a "string-course" of shabbiness on a bullet.
THE SAME CAN be DONE by CALIBERS WHICH ARE for sale In SHOPS UNDER CERTAIN KALIBR.
Chem nearer this "string-course" to the spout of bullet, the higher quality of barrel.
Thus, from a few barrels it is possible preliminary to choose the best.