Measuring the headspace on a .338 LM
- Thread starter nsgallup
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Headspace gauges, to check headspace of the rifle. These don't give a measurement, it is a pass - fail system. A set of multiple gauges can be used to get actual measurements.
There are gauges that measure the cartridge case. Is this what you are thinking about?
Google "rcbs precision mic".
There are gauges that measure the cartridge case. Is this what you are thinking about?
Google "rcbs precision mic".
If your talking about measuring your fired cases to adjust shoulder bump I prefer the Hornady cartridge case headspace gauge.
Below measuring a fired .223/5.56 case from my AR15 carbine to setup my die for the proper shoulder bump.
The advantage with the Hornady gauge is you only need to buy one gauge over buying a gauge for each caliber. I have Wilson type cases gauges and a RCBS precision Mic in .308 and prefer using the hornady gauge over any other type gauge.
Below measuring a fired .223/5.56 case from my AR15 carbine to setup my die for the proper shoulder bump.
The advantage with the Hornady gauge is you only need to buy one gauge over buying a gauge for each caliber. I have Wilson type cases gauges and a RCBS precision Mic in .308 and prefer using the hornady gauge over any other type gauge.
The Hornady tool lets you locate where any given bullet contacts the leade.
The RCBS tool can be used to measure cases from a headspace point of view. Can be used to set sizing die to minimize how much the brass is worked.
Seating measurement is usually base to ogive, headspace is base to datum line on the case shoulder.
I don't think that there would be any interference between these tools. They are doing different things.
The RCBS tool can be used to measure cases from a headspace point of view. Can be used to set sizing die to minimize how much the brass is worked.
Seating measurement is usually base to ogive, headspace is base to datum line on the case shoulder.
I don't think that there would be any interference between these tools. They are doing different things.
Exactly what do you want to measure, as far as I know rifle headspace, cartridge headspace and measuring how far off the lands are separate type gauges.
You are correct that you would have to order a custom bushing for the Hornady cartridge case headspace gauge. And the RCBS precision Mic would be my second choice depending on cost difference.
You could also use the Innovative Technologies Digital Headspace Gauge or even go old school and set the shoulder bump by feel and a felt marker for finding the lands.
You are correct that you would have to order a custom bushing for the Hornady cartridge case headspace gauge. And the RCBS precision Mic would be my second choice depending on cost difference.
You could also use the Innovative Technologies Digital Headspace Gauge or even go old school and set the shoulder bump by feel and a felt marker for finding the lands.
I am looking to measure seating depth which I understand can be done with the Hornady modified case and OAL length gauge (which I currently have), and also the head-space so that I can fit the cartridges more accurately to the dimensions of the rifle.
Leatherstocking
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I have the Hornady tool as pictured, and use it to compare both cartridge base to shoulder, and case base to ogive.
I use the stripped bolt method to find both max case head to datum, and case base to ogive for my chamber.
No actual measuring involved. With the firing pin out of the bolt you can feel when the bolt closes easy.
For seating depth, seat a bullet long, then chamber it, then seat a bit deeper,....until the bolt closes easy.
For shoulder setback, same thing. Just keep setting the shoulder back until bolt closes easy. You have to remove lube from the case before trying it in the chamber.
Mark and keep these cases for setting up dies.
I use the stripped bolt method to find both max case head to datum, and case base to ogive for my chamber.
No actual measuring involved. With the firing pin out of the bolt you can feel when the bolt closes easy.
For seating depth, seat a bullet long, then chamber it, then seat a bit deeper,....until the bolt closes easy.
For shoulder setback, same thing. Just keep setting the shoulder back until bolt closes easy. You have to remove lube from the case before trying it in the chamber.
Mark and keep these cases for setting up dies.
to achieve this, you must neck resize. only when the body has stretched enough to get the bold hard to close, then you use a body die.
all you have to do, is to adjust down the body die little at the time until your bolt close with no restriction.
you can also do it with a FL die
this is what I have been douing for over 20 years.
there are some very interesting tools that can speed up process, but it dont mean you absolutely need them.
I have the RCBS Precision Mic, and the bullet seating length tool is hit and miss at best, certainly not easy or positive in my opinion.
I think you might want to strengthen your fundamentals a bit in regards to reloading.
I think you might want to strengthen your fundamentals a bit in regards to reloading.
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