308 Winchester Case Capacities

Ok, I not only use the Hornady, but being the cheap bugger I am, I didn't buy the case shoulder set to go with it.

I made one of my own from the spare bullet ogive set. And yes as long as the bullet/neck is not too long it works.

So, it makes zero difference what the accumulated error is.

Going from memory, I get say 1.638 on a fired case.

I then work the dies until it sets back to 1.366 or 1.367.

It matches no one elses measurements, its a unique setup. I now the gun head-space (or I can let the grow grow until it is) is fine, all I need to do is bump it back .001 or .002.

Works just fine. The bullet adapter was just drilled out to hit the Ogive on a 30 caliber bullet. Did the same on 270.
 
Mr. Guffy
The Hornady/Sinclair tool started out as a comparator and then reloaders started renaming tools, it was about that time ever tool became a head space tool and everything had head space.

From the beginning I claimed the datum based tool had to have a sharp edged datum; a tool with a radius on the edge of the datum was not accurate. And then there is an exception. The exception is the L.E. Wilson case gage; the Wilson case gage has datum with a radius. They build the tool with the datum with a radius and then grind the tool to length.

F. Guffey
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The Hornady Tool is till a comparator. I believe that has been covered in a dozen plus threads. Reloaders did not start renaming tools, the guys making and marketing the tool decided what to call it. I am sorry they did not consult with you but I should point out they also did not consult with me. Now I figure there is nothing I or even you can do about their naming conventions. I guess if you were manufacturing gauges or tools you could call them or name them whatever you wanted to. You may wish to write them a letter voicing your displeasure and I wish you good luck on that.

Now can we just focus on case capacity and for example in the data I posted what would the effect be on chamber pressure for the same loads?

Thank You
Ron
 
Something I have always been curious about, looking at the numbers I posted, how much will it matter? We know that for a given load in less volume the generated pressure will be higher. Now with that in mind how great will the pressure difference matter? I don't have Quick Load which would use a software solution and if anyone who does would like to run the numbers please feel free.
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I've run the numbers through QL many times for .307 Win. Basically the same case capacity, similar bullets, just running lower pressure.
A 160 gr FTX load worked up in my 58.0 gr H2O capacity brass and running at 52k psi (SAAMI MAP) with CFE 223 jumps to more than 63k psi if put into 54.0 gr H2O brass.

The powder being used can have some impact on pressure increasing more dramatically, but the numbers are similar with .308 Win.
Running the same 160 gr FTX over Varget at SAAMI MAP of 62k psi in 55.9 gr H2O capacity brass, for example, will jump to over 69k psi in 53.8 gr H2O brass.
Oh... I forgot to note the velocity differences. I didn't record the actual predictions, but the difference is around 80 to 120 fps different with most powder/bullet combinations from a 20" barrel. (I was set for my 20" .307 and didn't think to change it while running the numbers for .308.)

As always...
Keep in mind that while QL is an exceptionally well-tuned program for cartridges like this, and the powder database is built with actual pressure testing, it is still just a simulation. Real world numbers would probably be close, but not the same.
 
RC20:
Ok, I not only use the Hornady, but being the cheap bugger I am, I didn't buy the case shoulder set to go with it.

I made one of my own from the spare bullet ogive set. And yes as long as the bullet/neck is not too long it works.

So, it makes zero difference what the accumulated error is.

Going from memory, I get say 1.638 on a fired case.

I then work the dies until it sets back to 1.366 or 1.367.

It matches no one elses measurements, its a unique setup. I now the gun head-space (or I can let the grow grow until it is) is fine, all I need to do is bump it back .001 or .002.

Works just fine. The bullet adapter was just drilled out to hit the Ogive on a 30 caliber bullet. Did the same on 270.
Click to expand...

While I love being retired something I really miss is in my little skunk works we had a really sweet machine shop where we did prototype work. I was not a machinist or mechanical engineering type but had the pleasure of working with some of the best in the business. There were so many gauges I wanted to make before my last day and just never managed to get to.

I also use the Hornady and I like the RCBS Precision Mic gauges. The ones I have were bought many years ago and also were left over inventory. I just wish I still had that machine shop and lab at my disposal for side projects. :(

Ron
 
FrankenMauser, thanks for contributing that information.
As always...
Keep in mind that while QL is an exceptionally well-tuned program for cartridges like this, and the powder database is built with actual pressure testing, it is still just a simulation. Real world numbers would probably be close, but not the same.
Click to expand...

Absolutely, it's a software solution based on their algorithm.

Ron
 
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I've done a good amount of case volume measuring . I've always done it with fire formed cases . The reason being is as cases are work hardened they have different amounts of "spring back" from case to case and manufacturer to manufacturer . This can actually cause inconsistent volume measurements from case to case . Add in range pick up brass with no known history and I'm not sure how consistent sized cases will be .

That said I'd love to see what those cases produce as far as internal volume after they've been fired all from the same rifle . This could show for sure if measuring case volume with a fire formed case gives a more consistent result .

Truly waiting at the edge of my seat for the results .

EDIT : just got to thinking , I already have a lot of case volume data from multiple manufacturers in both 223/5.56 and 308 cases . Now all I need to do is go size those same cases and re-measure . Unfortunately I no longer have the exact cases I used in the first measurements separated from the greater lots of brass they were pulled from . Not sure I'd get the true results I'm looking for by randomly pulling cases from those same lots of brass .

Well let me put some thought to this , maybe I do the test again using all the same brass this time . I have lots of at least 8 different brands of brass , this includes different year stamps of LC brass to also include LC-LR brass .

The thing is , that would take me a few months to complete . I to have way more things going on in my life then I really have time for . Adding to that is really not the best idea right now . I can pull from the existing fired lots and size those and see if there is a difference then the fired cases from the same lots . That could be done relatively quickly compared to having to actually load and shoot the rounds as well .

Now lets just see how motivated I am . I've been so busy lately that I actually have to schedule time to do nothing just to be sure I get some rest .
 
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Metal god, if you can manage the time then please do. My brass was all once fired in the same rifle with the exception of the GI brass (WCC and LC). All the brass was run through a full length set of RCBS dies and sized the same. I did measure each case following sizing using an RCBS Precision Mic. The outside dimensions are about as close as I'll ever get them.

Ron
 
Reloadron : I'll see what I can do . I'll check what fired cases I have now on hand . I could measure the fired cases then turn around and size those same case and remeasure . That I think could be done in a couple hours time . I think I can do that some time soon . My guess though would be most if not all my existing fired cases are LC only brass . I've not loaded RP , Win , or Fed cases in quite some time ( at least 3 years ) . Now I know I have some of those cases laying around or even separated into lots but I won't remember the history of them . I have multiple rifles in those same calibers so knowing which rifle they came out of may prove difficult .

That said I know I have LC brass and WCC brass with a well documented history to pull from .

I'll see what I can do .
 
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Metal god, anything you could kick in is most appreciated. While I am retired time has been consumed with other things right now. I know the drill with time. :)

Thanks
Ron
 
I look forward to your results.

It is my untested opinion based upon experience that weight sorting does not mater nearly as much as head stamp origin sorting. This suggest neck tension is more important than case volume. I have a friend that turns his necks. I mocked him until I shot them. When it has to be an X at 1,000...

For us mortals, your test results will be interesting.
 
"I am the only reloader that..." to your hearts content.

And then there was the assumption

do not want to hear about re-loader's this, that or another.



OMG, you guys make me laugh. :) thanks
 
Ron, I think its too late to pull this one out of the gutter. You have only posted the weights of your test cases and we are on page 2 of nothing to do with the original post. Its been an sad but funny post with no conclusion.

When a reloader writes a post he often wishes to have the topic of his post discussed. And then their is the reloader who often sidetracks the discussion, I once new a reloader like that. He would tell story's of past glory in riddles only he could understand. Trying to impart some wisdom on his peers. I am the only reloader that understands, when the bolt closes and the lights go out, it was a community of shooters that made the read worth while. :)

Please start a new thread when your experiment is complete, I would love to read your conclusions. Maybe replicate your test and draw my own.
 
OK, folks, I've done some thread pruning.

The OP has requested that replies focus on CAPACITY. Has requested it several times, actually.

Not tools, not powder column lengths, not anything else.

If you want to talk about that, start your own thread.
 
Thanks Mike. I should have started doing that on page one. I've been out of the country the last week and made the mistake of thinking I'd keep up by tablet, but connectivity proved too intermittent.
 
Ok so what I have on hand with known history to run some capacity test are all 308 cases and are as follows

15 - LC14 twice fired including once reloaded

15 - LC12-LR three times fired including twice reloaded

15 - Fed GMM cases once fired from factory new loaded cartridges

15 - Lapua once fired from factory new virgin brass .

I went ahead and wet tumbled those all today and will do the capacity measurements sometime this week .

Please stand by :D
 
Update and question : Sorry thought I'd get to this sooner but been dealing with caregiver duties for both parents and a aunt as well as trying to work . To top it off I've been sick as a dog the last 5 days . I'll get this done , it's just going to take a little longer then I thought .

So far I've de-primed , wet tumbled , trimmed to 2.000 and weighed each fire formed case I will be using in the test . After all of that I only have 11 of each sample lot noted in my earlier post . I also numbered each case 1 to 11 so I'll actually be comparing the same empty case weight to the same full case weight . The other thing of note is that the LC-14 , Lapua and LC-12-LR all were fired from the same Savage model 10 while the Fed GMM cases were fire in a Ruger PR .

Ok that's were I left off but I've run into a bit of a dilemma IMO . Every other time I've measured case capacity I've left the spent primers in . How ever this time I did not and when plugging the primer pocket with model clay . I found that on some cases but not all the clay would push up through the flash hole into the case . No problem I'd just take a small flat head screwdriver and knock that down flush inside the case . While doing this I came to realize that there is no real way for me to plug the primer pockets with a consistent amount of model clay . Meaning each plug will likely weigh different then the last . Am I wrong in thinking this is going to throw off the whole test ?

I know I can plug the primer pocket then weigh each empty case but there again I'm not going to have the same weight plug in each pocket throwing off the actual empty case weight .

My thinking write now is to either deprime some spent cases and re-seat those spent primers in my test case OR just seat some new primers in the test cases and continue on ????
 
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Metal god writes:

Ok that's were I left off but I've run into a bit of a dilemma IMO . Every other time I've measured case capacity I've left the spent primers in . How ever this time I did not and when plugging the primer pocket with model clay . I found that on some cases but not all the clay would push up through the flash hole into the case . No problem I'd just take a small flat head screwdriver and knock that down flush inside the case . While doing this I came to realize that there is no real way for me to plug the primer pockets with a consistent amount of model clay . Meaning each plug will likely weigh different then the last . Am I wrong in thinking this is going to throw off the whole test ?
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I can feel your pain on that. Since I only had 50 cases I meticulously, using a flat toothpick, used my same little ball of clay to keep things consistent. I doubt what happened will really have much effect on the overall numbers especially in view of the case count.

I hope to get this science experiment concluded soon but a few things have come up of personal nature which has taken my time away from play. With luck I can resume my normal play time around late June.

Ron
 
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