Gunsmithing Gunsmiths, Explain Barrel Contours please.

[wjwill]

I have alway wondered about the different contours of barrels and thier general uses. Can some gunsmith's please chime and explain what is the benifits of having one contour over the other. I have a number 7 contour on the rifle I just had built, but not really sure what a number 7 contour means and does to improve my shooting.

Is there maybe a chance a smith can go through all the contours by number and explain what that type of contour is mostly used for going by number? Even a couple of pictures from the contours that are mostly used would be helpful. I'm pretty sure I'm not the only who have always wondered about this.

Thanx, Wesley

 

[bohem]

Re: Gunsmiths, Explain Barrel Contours please.

Weight vs. Stiffness trade off.

A match gun that's going to be transported from safe to car to bench to car to safe can weigh whatever you want it to (as long as it clears the rules for that class)

I sure as heck don't want to be carrying a 17lb rifle around the woods all day though. That's where the sporter barrels come in.

Generally a nice light 30-06 is going to be easy to carry and will see about 1-5 shots at a time. 20 shot strings of 308 with 175gr bullets will make you cry uncle from a 7lb rifle.

As barrel stiffness goes up there's an increase in accuracy and barrel changes are decreased from heat influences.

Length is important too. A 18" barrel is stiffer than a 26" barrel (for equivalent contours) by a factor of 5 fold sometimes.

The #7 contour is dependent upon what maker it is, but a #7 shilen contour is like a heavy varmint taper. It's about the same as an Adams and Bennet F54 contour.

 

[oldgrayone]

Re: Gunsmiths, Explain Barrel Contours please.

what bohem said plus you can go to the barrel makers web sites where they have a drawing showing where each measurement is taken and how it relates to a each contour.