25-06 head space

3

308Loader

New member
Hello again everyone. I recently started loading for my Thompson center 25-06. set up my dies per manufactures instructions and loaded a few before I got my Wilson gage. They all functioned well, I ran a couple of load ladders... So my case gage showed up today and I was shocked to find the head space of a fired case and a resized case were the same. They went plunk unto the gage and looked good. So I measured them with a comparator and indeed they are the same 2.050". Thinking maybe the load was light and didn't stretch the brass or something I went to a spent box of Hornady and they also measure the same. What gives? My 308 and 223 cases stick out the end of the gage when they haven't ben sized.

My load 45.7 to 50.8gr imr4350 under 100gr sp / 2800fps to 3100fps

Box ammo custom Hornady 117gr sst #81454 2990fps
 
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Would this be a good example?
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It is not likely the Hornady case comparator and the Wilson case gage is going to agree, the Wilson case gage does not have numbers, unless;) you have a straight edge with the companion tool to the press, the feeler gage. when using the straight edge and feeler gage the reloader does not need the Hornady/Sinclair etc. tool.

I would suggest measuring the length of the case from the shoulder to the case head before firing, then measure the length of the case again after firing.The reloader needs to know what effect the chamber had on the case when fired. Where else is the reloader going to find the magic .002" bump:rolleyes:.

My thinking:eek: If a reloader can manage to reduce the length of a case from the shoulder to the head of the case .002" they are well on their way. I also consider the magic .002" bump could be an auto response.

F. Guffey
 
I was shocked to find the head space of a fired case
and a resized case were the same.
Click to expand...
You simply have a tight chamber (circumferentially) and Min headspace.

Count your blessings and FL resize w/ confidence. ;)
 
And, when comparing I suggest a reloader use a standard, I make standards, I use standards as transfers and standards. The head space gage is a standard. I use the head space gage to check the ability of a die and shell holder to restore a case to minimum length, or as they say "full length sized a case".

I also use head space gages to check chamber gages and chambers, I know that sounds expensive, but when a reloader gets comfortable with gages they find it is not necessary to have all three head space gages like the go, no and beyond.

F. Guffey
 
308Loader,

What does a new, never-fired case look like on the comparator? I believe you will find it at least 0.005" shorter and that you are not resizing fully. Keep in mind that as a case enters the sizing die, the sides make contact with the die first, so you are actually squeezing the case narrower and longer at first. Contact with the die shoulder then pushes the shoulder back. You may simply have not pushed it back as much as you intended.

If that is the situation, and if you have already tightened the die down as far as it can go in your press, then I would suggest removing the decapping pin and expander and using a shim under the case to set the shoulder back another thousandth or two for your chamber. You would then have to expand it separately afterward. I use the Redding body dies, which don't touch the neck, to avoid this issue and let me use a shim, but it's still an extra step. If you know your sizing die is already turned past solid contact with the shell holder deck and you see no crack of light between the two when you have the case run all the way up into the sizing die, if you know someone with a lathe and toolpost grinder, they could shorten your sizing die by a thousandth of an inch or two, which will set the shoulder back that much more. They could also just grind that much off the shell holder deck. Indeed, you can do that with wet/dry paper spray-glued to a sheet of plate glass.

Unfortunately, the 2.050" number is not a usable absolute measure, as the comparators generally have a little radius at the mouths of their holes that cause them to read anywhere from a couple of thousandths to a dozen thousandths shorter than actual value. Without a headspace GO gauge to use as a reference to compare your reading to, we can't really tell how close the 2.050" number is. I can say that I would expect new brass to be about 2.047" in an absolute measurement and that, allowing for the comparator hole radius, yours is probably at least 0.005" bigger than that.
 
I have no more factory ammo left to check against. I used the competitor against a sized and reloaded cartridge, a fried reloaded cartridge and a factory once fired cartridge. I understand the comparator is just giving me a comparison measurement between the three. Out of a box of 50 fired and not sized cartridges I ran through the gage 5 or so are above the max on the gage by just a smidgen. The ones I have loaded and shot fit the chamber just fine and shot a nice group at 100yrds. I guess my initial concern was that the gage was cut wrong or something.
 
Cartridges do not have headspace. Nor can you use head space gauges to check chamber gauges and chambers. Headspace gauges measure nothing.
"...My load 45.7 to 50.8gr..." Current data gives 48.0 to 52.8.
 
Headspace gauges measure nothing.
Click to expand...

I know, when the bolt closes the chamber is a dark place, that is no reason for the light to go out behind the eyes and between the ears. I am the fan of standards and transfers. I guess that makes the only reloader that can measure the distance from the shoulder of a die to the deck of the shell holder.

I was doing some gun business at a gun parts gun store when a man walked in with a magnificent rifle. He wanted the head space checked. The owner/smith informed the owner he did not have a head space for the rifle. The man left. I then informed the smith/gun parts owner I could check the length of the chamber on any rifle three different ways without a head space gage. The owner did not get smart or snarky, he did not show off, he simply ask "HOW?"

When I finished he said "I'll be D@#$ed",

F. Guffey
 
I may have used the wrong term here. I am using case gages that will tell me if the case has ben sized to spec and trimmed to length. If the case hasn't ben resized in circumference, and the distance from the shoulder to the case head (head space?) it will stick up out of the gage. conversely if I am smashing the case too much with a die it will sit below the top of the gage because the distance from the shoulder to the head is too short. Also if the brass protrudes from the bottom of the gage (provided the case head and shoulder is where it needs to be) the case is longer than trim length. They are pretty handy tools, and yes all of this can be done with calipers. The gage is quicker and works with the way I process my brass. I can provide pictures if need be. No need to get all worked up on this topic, just an observation I thought I would ask a more knowledgeable community. Thanks every one for your input.
 
F.Guffey I am interested in your "fan of standards and transfers" can you define or elaborate for me. I have seen this stated before by you but not sure I fully understand.
 
t.o'heir,
"...My load 45.7 to 50.8gr..." Current data gives 48.0 to 52.8.
Click to expand...

My first ever loading for this 25-06. Started at Hornady book min and didn't go to max. Got to start somewhere, I'm sure I can find other min-max loadings else where. Just a trial load ladder that seemed safe to get a feel for this cartage and powder combo.
 
Cartridges do not have headspace.
Click to expand...
Cartridges do have a headspace dimension.

And when the sized case headspace dimension is equal to/very slightly less
than the fired case dimension, then all's right w/ the world.
;)
 
Cartridges do not have headspace.
Click to expand...

There is a member of many forums that called SAMMI, I do not have all the details but the member had insisted the case had head space for so many years when it was pointed out to him SAMMI did not list head space for the case he called them.

Plain and simple, there is a symbol for head space, the chamber has head space, it looks like a rail road crossing symbol that is clocked at 45 degrees. The symbol is absent on case dimensions, anyone that owns and has read:eek: R. Lee's book on modern reloading should know R. Lee is the only publisher that includes the datum to case head measurement for cases, he does not include all of the pluses and minuses.

Then someone called RCBS, I believe they reported me for saying the ROCK CHUCKER does not cam over. I was told someone at RCBS said something like: "Have him call me at this number".

I have had some interesting conversations with manufacturers, answering the phone can be complicated. How does one start the conversation when they want someone to take them seriously? "HI, I am the greatest shot since Annie Oakley".

F. Guffey
 
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