geo57
Member
Among those of you that have used the Zero .38/.357 158 gr. JHP bullets do you have any thoughts on them good or not so good such as being inconsistent, over the .357" designation, etc ? Thanks.
Yep. .358 is perfect. You are GTG.Thanks all. Since I ordered, two fellas reported that the bullet I inquired about mic @ .358" or a wee more. Have you last 4 posters ever measured yours ?
All the time I read of individuals who have picked up their digital caliper, measured something, and believe that their caliper is truth. Well the fact of the matter is, all measurement equipment looses its calibration and requires re calibration. Maybe it is still accurate to the hundredth's of an inch, but believing something is forever in calibration at the thousandths, or ten thousandths, without continual re calibration, is delusional thinking. And that includes gauge blocks:Thanks all. Since I ordered, two fellas reported that the bullet I inquired about mic @ .358" or a wee more. Have you last 4 posters ever measured yours ?
I understand and agree. I think it’s because most reloaders are taught to think in terms of bore size when what they’re using is actually the groove dimension. And, like every other dimension there are tolerances, variations and of course wear. It’s hard to explain that a .359” projectile and a .355” projectile are both perfectly in spec for a .357” groove barrel. The bore is going to be closer to .350” anyway.All the time I read of individuals who have picked up their digital caliper, measured something, and believe that their caliper is truth. Well the fact of the matter is, all measurement equipment looses its calibration and requires re calibration. Maybe it is still accurate to the hundredth's of an inch, but believing something is forever in calibration at the thousandths, or ten thousandths, without continual re calibration, is delusional thinking. And that includes gauge blocks:
from the The Gauge Block Handbook
2.2.4 Recalibration Requirements
There is no required schedule for recalibration of gauge blocks, but both the ASME and Federal standards recommend recalibration periods for each tolerance grade, as shown below:
Grade Recalibration Period
0.5 Annually
1 Annually
2 Monthly to semi-annually
3 Monthly to semi-annually
Most NIST customers send master blocks for recalibration every 2 years. Since most master blocks are not used extensively, and are used in a clean, dry environment this schedule is probably adequate.
I have much more confidence the gauges and measuring equipment of a bullet manufacturer is in calibration traceable to the National Institute of Standards than the calipers of a home reloader. However, without verifying what anyone is doing, this is a non evidentiary based belief.