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oomans, we need your assistance and digital dexterity. Could those of you who shoot .45 ACP measure the case rims for us please?

We'd like to know:

1. The case rim diameter in mm
2. The brand of ammunition measured
3. The consistency of the diameter

The cases are nominally 12.19 mm across the rim diameter but we're interested in seeing if any particular brands show a tendency to deviate from that measurement.

I would love to help but I have no instruments calibrated for the strange alien units you require the measurements in.

Our preference would be for Imperial measurements but we were making the assumption that most of the skinflints out there would be equipped with cheap Chinese digital verniers rather than good old Moore and Wright Imperial micrometers...

It so then you cannot be serious about the measurements you may be offered.

We get what we expect.

Low expectation = low value returns.

Ah, but having listened to oomans prattle on for a while we're quite adept at winnowing the wheat from the chaff. Consider this an exercise in clown sourcing...

Poor measurements are poor measurements and you could just be landed with a load of metric chaff with no wheat.

Still it will no doubt pass the time for you, something we all have to do 'till we are dead.

*ushers dromia to a fireside seat, paws him a pint*

Right oomans, now back to the task...

Do you not own a half decent reloading manual which lists SAAMI spec? Any decent manufactured brass will conform to this. They sign up to it.

And worked brass can differ from one case to the next. Stick to SAAMI and you may save yourself considerable headaches trying to "standardise" from batches of fired or unfired brass from different makers.

The interest is in physical dimensions of the case rim, not what is specified in the manual or reamers lists. Not all cases are equal and it would be good to find a .45 case with a slightly smaller rim diameter out of the factory, look on it as bottom end of the dimensional tolerances.

Anyone?

yes ooman: they sign up to SAAMI. But do they achieve it, or is one brand a few thou larger than nominal? Another brand a few thou smaller? And if so, which brand?