Case gauges

[Nick Danger]

I have several case gauges to help in my reloading…. The one that doesn’t seem to be in spec is my 357 magnum gauge. After trying 30 different brass cases on roll crimp and taper crimp none of them fit this gauge. Yet all these reloaded cases fit my S&W trooper mk3. Now if I use a factory loaded bullet to test the gauge it slides in like it should…. I’m at a lose Help Mr Wizard

 

[slowworm]

Chambers are always cut loose, the question is how loose. My 303 chambers are cut huge to cope with dirty conditions on the battlefield and I have really poor brass life unless I neck size. My match chambers are much tighter and get a shoulder bump.

I suspect the 357 chamber is somewhere in the middle of those 2. The fact that your loaded ammo fits the chamber doesn't mean all that much, other then it's not grossly out of spec.

So,

How do you know the die is in spec?
You may not have enough of a taper crimp.

Measure the taper on the factory round (Neck, middle, head) and compare it to the same measurements on your loaded round. Then get back to us.

 

[FLIGHT762]

So, how do you like that S&W Trooper MK3?

 

[DownhillFromHere]

At what point do your reloaded rounds stick in the gauge, and on which part of the brass - for that matter, which gauge are you using? How many times has your brass been reloaded?

If it sticks on the brass very close to the rim, it's possible - perhaps likely - that the case web (the solid part of the head) has expanded. I had this problem years ago with many-times-reloaded 9mm brass that ran fine in Glock and Sig-Sauer service pistols but jammed tight in my CZ TSO. I bought a gauge, and sure enough, the rounds that stuck in the CZ stuck in the gauge.

Yes, the .357 is a straight case and 9mm is tapered, but the principle holds. One of the techs at Dillon Precision told me that standard dies aren't able to resize the web. Lesson learned. I gauge all my reloads now; the ones that don't plunk into the gauge go into a "Glock jar" - Glocks will eat dang near anything.

It sounds like your Trooper may have a service-spec chamber a bit more generous than the SAAMI-spec gauge.

 

[mtrmn]

So, how do you like that S&W Trooper MK3?

I see what you did there

 

[MtnCreek]

Either expanded above the rim or could be over belling. Lead or jacketed?

Either way, your cylinder is the better gauge.

 

[918v]

Factory ammo is sized smaller than your reloads, therefore it fits your gauge. Your reloads could be bigger for any number of reasons. Do you have a dial caliper? Tried measuring your reloads?

 

[greentick]

OP, don't write off the possibility that the gauge is defective if you just got it new. I have a few EGW "chamber checkers." For 9, 10, 556 that I do in volume I have a 7 hole checker. It's peace of mind. If it fits the checker if definately fits my glocks. Anyhow, I bought a "multi" caliber checker that had 5 or so pistol calibers (I do occasional runs of 40cal low pressure plinkers for family and was looking at doing small runs of 45acp, so I got the multi-cal checker) and the 9mm hole was off, every factory or reload I checked wouldn't fit. I sent it back.

Also, some "case gauges" are just for checking to see your resized brass is in spec, not for checking a complete cartridge.

 

[spife7980]

Tried measuring your reloads?

I am still amazed that this isnt the first way anyone would go.

 

[smoothy8500]

One gauge mfr is minimum spec, the other mfr does max SAAMI spec. I quit using chamber gauge years ago and either take measurements or use my actual chamber to confirm.

 

[dnchrist]

Chambers are always cut loose, the question is how loose. My 303 chambers are cut huge to cope with dirty conditions on the battlefield and I have really poor brass life unless I neck size. My match chambers are much tighter and get a shoulder bump.

I suspect the 357 chamber is somewhere in the middle of those 2. The fact that your loaded ammo fits the chamber doesn't mean all that much, other then it's not grossly out of spec.

So,

How do you know the die is in spec?
You may not have enough of a taper crimp.

Measure the taper on the factory round (Neck, middle, head) and compare it to the same measurements on your loaded round. Then get back to us.

.303 has different projectile selection diameters to compensate for the wide range of .303 chambers.