My smith told me yesterday that on ordering a barrel of a certain twist, for instance say a 1 in 10 it could be anywhere from a 9.5 to 10.5 unless special order. Thats the reason for slow and fast barrels. fws
With button rifled barrels there have been cases where the twist is not exactly as advertised but I doubt that this is the explanation for fast or slow barrels. Cut rifled barrels are usually more precise as far as the regulation of twist rate is concerned. New methods for establishing twist rate which are being used in some buttoned barrels now may be changing this tendency for buttoned barrels to vary on occasion. Regards, Bill
Ditto Bill - Krieger and other cut rifled manufacturers can cut to exact twist rates. There can be some variations in the twist rates between barrel manufacturers, but this is generally a function of design specifications as ordered by the gun manufacturer. Button cutting can achieve the same perfect twist rate that a cut barrel has. The difference is a cut barrel achieves a smoother finish with sharper lands. If you air gaged a high quality cut VS buttoned barrel, there is no difference in dimensional quality.
Slow or fast barrels are not caused by variations in twist.
Posts: 10780 | Location: Test Tube | Registered: 27 February 2001
There's a company that advertizes in Precision Shooting that measures twistrate and prints out a graph of it with a line representing the actual twist and how close it is to the theroretical flat line.
Benchresters look for a barrel with a very consistent twist for several inches before the muzzle. It doesn't have to be exactly the intended twist, just steady.