klcarroll
02-02-2022, 03:07 PM
I started handloading .357 SIG almost 12 years ago, ...and it quickly became apparent that one of the first things the prospective reloader has to decide with this caliber is how to headspace it.
Like many, I gravitated towards using the case shoulder to control the headspace: I started that way, mainly because my Wilson Case Gauge was configured to measure relative to the shoulder. This worked well for me from a consistency standpoint, ...and using the shoulder for headspacing allowed me to form cheap, "plinking rounds" by reforming .40S&W brass. These "cheapies" functioned well, and even with the reduced loading I used in them, they were still more potent than typical 9mm loadings. (....And with the shoulder headspacing, the fact that they were .008" too short really didn't matter.)
Soon, however, questions began to arise: Every time I would drop a Factory Loaded .357 SIG round into my Wilson Gauge, the round would drop into the gauge a full .025" deeper than the Max Headspace shoulder on the gauge! I have tried Winchester, Fiocchi, Hornady, and DRT, and the result is the same!
The major ammo manufacturers are clearly producing these rounds to headspace on the case mouth, not on the shoulder. There is only one logical reason I can think of for doing this: ...Forming the case to headspace on the case mouth allows for a potentially longer neck to be created by setting the shoulder back a bit. In a short-necked case like the .357 SIG, every little extra bit of neck helps in the fight to properly retain the projectile, and fight bullet setback.
The obvious downside to headspacing on the case mouth is that the shoulder area will be much more severely worked, and case life will suffer: ......But in spite of that, I'm thinking that I will alter my setup to headspace on the case mouth so that I can find just a little bit more case neck.
What are your thoughts??
Like many, I gravitated towards using the case shoulder to control the headspace: I started that way, mainly because my Wilson Case Gauge was configured to measure relative to the shoulder. This worked well for me from a consistency standpoint, ...and using the shoulder for headspacing allowed me to form cheap, "plinking rounds" by reforming .40S&W brass. These "cheapies" functioned well, and even with the reduced loading I used in them, they were still more potent than typical 9mm loadings. (....And with the shoulder headspacing, the fact that they were .008" too short really didn't matter.)
Soon, however, questions began to arise: Every time I would drop a Factory Loaded .357 SIG round into my Wilson Gauge, the round would drop into the gauge a full .025" deeper than the Max Headspace shoulder on the gauge! I have tried Winchester, Fiocchi, Hornady, and DRT, and the result is the same!
The major ammo manufacturers are clearly producing these rounds to headspace on the case mouth, not on the shoulder. There is only one logical reason I can think of for doing this: ...Forming the case to headspace on the case mouth allows for a potentially longer neck to be created by setting the shoulder back a bit. In a short-necked case like the .357 SIG, every little extra bit of neck helps in the fight to properly retain the projectile, and fight bullet setback.
The obvious downside to headspacing on the case mouth is that the shoulder area will be much more severely worked, and case life will suffer: ......But in spite of that, I'm thinking that I will alter my setup to headspace on the case mouth so that I can find just a little bit more case neck.
What are your thoughts??