I have a dumb question

[L W P]

Kinda like a reference point as long as your using (which ever brand maker) the same tool for measuring each time.

 

[Uncle Ed]

Help...........call F. Guffey I lost my datums.

Below a .45 acp case on a .223 case.

Below a .45 acp case on a .308 Winchester case.

All humor aside, this is why I like the Hornady cartridge case headspace gauge. And if you have a GO or NO-GO headspace gauge the Hornady gauge can be adjusted to read actual headspace.

Below a Colt 5.56 Field gauge at 1.4736

Below the same field gauge in my "adjusted" Hornady gauge, all you do is use feeler gauges between the red and silver sections of the Hornady gauge. The case read .011 smaller than the Field gauge, so a .011 feeler gauge was used to adjust the gauge.

Below measuring a .223 case with the proper and "adjusted" adapter for the case. And the gauge came with adapters for every caliber.

Below my RCBS Precision Mic that is caliber specific and cost more than the Hornady gauge.

 

[Sniper338]

The sinclair headspace guages are the best bang for the buck when you load for abunch of things like I do...

 

[gilream]

Wrong......it's a barrel stub with the finish reamer run partially in......

Barrel stub with reamer partially run into it makes the very best headspace gauge IMO. As long as the diameter is releived if needed to allow a fired case to slide easily and fully into the gauge.

 

[Dusty Stevens]

Barrel stub with reamer partially run into it makes the very best headspace gauge IMO. As long as the diameter is releived if needed to allow a fired case to slide easily and fully into the gauge.

If its made with your reamer and a fired case wont go in there you got bigger issues

 

[bobinpa]

Comparator tool...

Example we use it to measure OAL off the oj with a bullet seated.

When measuring case shoulder bump, do yall use a bigger caliber comperator, say a 30 cal to measure the shoulder on a cartridge with a 6mm neck? So it goes over the neck?

Or what tool is used best for measuring shoulder bump

The best way for me is to have a barrel stub made with the same reamer as Alf has said.

The second best way is to buy Whidden dies and use the shoulder bump gauge that they supply with the dies.

The third way, when all else fails is to use an empty pistol case as others have said. I have 3 of them, a .32, a 9mm and a 44mag. I cut them off and then put them in my case trimmer and "trim" them down to about 1/2" - 5/8" long so they don't wobble when I use them. The case trimmer does a good job of keeping them square. After a little practice it is easy to get repeatable measurements.

The pistol cases are by far the cheapest. Good luck.

 

[Toolbreaker]

Any of the above methods work. This is one that I made for my .223.