quote:

Originally posted by tonelar:
mebbe ask the armorer?

quote:

Originally posted by Xer0:
Sig pistol barrels are cold hammer forged from a single billet of steel (unless something has changed that I am unaware of). They are not two pieces put together. There is no heat treatment besides a possible heat soak for stress relief. Gun barrels are not like knives where it is tempered and quenched to hardness. You cannot post-temper barrels beacuse tempering heat would warp the barrel rifling dimensions/straightness. Plus barrels need some flexibilty and softness for chamber area pressure expansion/contraction.

Cold hammer forged barrels are more durable than typical cut-rifled barrels because the repeated hammering actually hardens the steel from repeated movement of the steel (AKA work hardening), but is still very low in hardness in comparison to say a good knife blade. Typical button-cut (or the other rifle cutting method which name escapes me at the moment) rifling barrels cannot be too hard of a steel for the rifling cutting to work (at least with typical cutters).

Even if a pistol barrel is a two piece affair, doesn't necessarilly mean it will necessarily be horrible. Pistol barrels are not rifle barrels and don't suffer the extremes of pressure and heat. The major issue with pistol barrels of two piece designs is accuracy (not safety) if the they are put together imprecisely or poorly in the first place. With two piece barrels, the heat is not transferred evenly and the expansion coefficients change at different rates on the two pieces. Any imperfections that affect accuracy with the fit of a two piece barrel get exacerbated by the dimensional changes with heat.

Safety-wise, there is no real issue on "pistol" barrels. With high-pressure and high-heat rifle barrels it's a different story, but you can't reload and shoot a pistol fast enough (well maybe a full auto glock 18 or something similar with high cap mags, although it is still much more likely something else will break before a two piece pistol barrel would fail) to compromise the structural integrity of a two-piece barrel.

Added: Assuming that Sig barrels are still one-piece affairs, there could very well be a finished color difference between the rifled portion of the barrel and the chamber because of the different hardness. The thin rifled portion of the barrel will be harder than the chamber area as this area is work-hardened by repeated hammer blows, whereas the chamber portion is not.

quote:

Originally posted by GrandPotter:

quote:

Originally posted by Xer0:
Sig pistol barrels are cold hammer forged from a single billet of steel (unless something has changed that I am unaware of). They are not two pieces put together. There is no heat treatment besides a possible heat soak for stress relief. Gun barrels are not like knives where it is tempered and quenched to hardness. You cannot post-temper barrels beacuse tempering heat would warp the barrel rifling dimensions/straightness. Plus barrels need some flexibilty and softness for chamber area pressure expansion/contraction.

Cold hammer forged barrels are more durable than typical cut-rifled barrels because the repeated hammering actually hardens the steel from repeated movement of the steel (AKA work hardening), but is still very low in hardness in comparison to say a good knife blade. Typical button-cut (or the other rifle cutting method which name escapes me at the moment) rifling barrels cannot be too hard of a steel for the rifling cutting to work (at least with typical cutters).

Even if a pistol barrel is a two piece affair, doesn't necessarilly mean it will necessarily be horrible. Pistol barrels are not rifle barrels and don't suffer the extremes of pressure and heat. The major issue with pistol barrels of two piece designs is accuracy (not safety) if the they are put together imprecisely or poorly in the first place. With two piece barrels, the heat is not transferred evenly and the expansion coefficients change at different rates on the two pieces. Any imperfections that affect accuracy with the fit of a two piece barrel get exacerbated by the dimensional changes with heat.

Safety-wise, there is no real issue on "pistol" barrels. With high-pressure and high-heat rifle barrels it's a different story, but you can't reload and shoot a pistol fast enough (well maybe a full auto glock 18 or something similar with high cap mags, although it is still much more likely something else will break before a two piece pistol barrel would fail) to compromise the structural integrity of a two-piece barrel.

Added: Assuming that Sig barrels are still one-piece affairs, there could very well be a finished color difference between the rifled portion of the barrel and the chamber because of the different hardness. The thin rifled portion of the barrel will be harder than the chamber area as this area is work-hardened by repeated hammer blows, whereas the chamber portion is not.

I agree 100%. Yea right! Like I know this stuff.