308 Winchester Case Capacities
- Thread starter Reloadron
- Start date
Hello I'm back !! ;-)
Ok I started over on my case volume test and just seated new primers in all the cases to seal the primer pockets . I have 4 sets of 11 cases to test . Of the 44 primers I seated I weighed 12 of them . They all weighed 5.3gr so that's 25% of the primers weighed and all weighed the same .
Don't get to happy I'm not done yet but should finish by tomorrow night
Hope to have some numbers for you all some time tomorrow evening PST so it may be quite late for some of you . I just need to do the water capacity measurements on the LC-12-LR and Fed GMM cases , the other two sets ( Lapua and LC-14 ) cases are finished .
Hope to see you soon
Ok I started over on my case volume test and just seated new primers in all the cases to seal the primer pockets . I have 4 sets of 11 cases to test . Of the 44 primers I seated I weighed 12 of them . They all weighed 5.3gr so that's 25% of the primers weighed and all weighed the same .
Don't get to happy I'm not done yet but should finish by tomorrow night
Hope to have some numbers for you all some time tomorrow evening PST so it may be quite late for some of you . I just need to do the water capacity measurements on the LC-12-LR and Fed GMM cases , the other two sets ( Lapua and LC-14 ) cases are finished . Hope to see you soon
Each to his own. Some hunt, some target shoot
Two totally different goals using the same type (often not the same equipment)
As a advanced middle age guy (old fart) with ruptured disk, my hunting days are gone.
Its a challenge and fun to put 5 rounds into as small a space as you can.
Back in the day though, I still did the same drill off a bench.
Why? Because I needed to know what the gun and ammo were doing without knowing what I was adding to the mix.
I think I only did one free hand shot hunting. All others were braced one way or the other. The goal was not to find out how great a standing shot I was, it was to get the animal into my freezer.
I did know if I missed ( once and that was the free standing shot due to the situation not what I normally did) it was not the gun or ammo.
Sorry guys , I totally forgot why I was doing this . I got done measuring all my fire formed cases and realized I now have to size them all and do it again . What I was supposed to be doing is comparing the differences of fire formed cases to FL sized cases correct ???
My bad , it will take another day or so to finish . I have the LC-14 cases fully completed but need to size and remeasure the other 3 lots .
My bad , it will take another day or so to finish . I have the LC-14 cases fully completed but need to size and remeasure the other 3 lots .
FrankenMauser
New member
RC20, you nailed it.
Even though I'm a hunter before all else, I want that "competition" accuracy to guarantee that I know where the bullet is going to go.
As my brothers put it in regards to a couple of my loads, "You get to pick which hairs you'll cut on the way to the [animal's] heart."
Just because "minute of deer" is good enough for some people, doesn't mean it's good enough for me in most applications. (I, admittedly, do have a few "good enough" rifles and loads. ...But they're used where "good enough" is 'more than enough'.)
Sadly, though probably younger, I'm approaching the same "wall": Injuries and complications are piling up. I can't pack elk quarters out any more, which pretty much kills serious elk hunting. And even Mule Deer are a bit of a challenge, since my back can't handle much hiking. I fear my big game days are numbered.
Before long, the case prep, sorting, and precision 'hair cutting' loads will be behind me. I'll be, at best, hauling a shotgun or rimfire around to fill the freezer with bunnies and grouse.
...But it won't stop me from still wanting tiny groups at the range.
Even though I'm a hunter before all else, I want that "competition" accuracy to guarantee that I know where the bullet is going to go.
As my brothers put it in regards to a couple of my loads, "You get to pick which hairs you'll cut on the way to the [animal's] heart."
Just because "minute of deer" is good enough for some people, doesn't mean it's good enough for me in most applications. (I, admittedly, do have a few "good enough" rifles and loads. ...But they're used where "good enough" is 'more than enough'.)
Sadly, though probably younger, I'm approaching the same "wall": Injuries and complications are piling up. I can't pack elk quarters out any more, which pretty much kills serious elk hunting. And even Mule Deer are a bit of a challenge, since my back can't handle much hiking. I fear my big game days are numbered.
Before long, the case prep, sorting, and precision 'hair cutting' loads will be behind me. I'll be, at best, hauling a shotgun or rimfire around to fill the freezer with bunnies and grouse.
...But it won't stop me from still wanting tiny groups at the range.
Me said:
When working up a load I use a front and rear bag , sometimes a bipod and rear bag prone if that's how the rifle and or load for that rifle is intended to be used . I consider my self a pretty good shot and I couldn't tell if my load could or could not shoot a 1/10 of a moa better , I'm just not that good , I wouldn't even know what to do to squeeze that little bit more out of a load .
I'd love to see some of your guys groups where it was small enough to notice 1/10 moa differences from shot to shot I'd also like to know when you are shooting that small of groups . How do you know what to do to make them better ? . Maybe I'm wrong but it would seem to me the group could not be much larger then the width of the bullet if shooting 30cal . I can shoot groups with all bullet holes touching in a cluster ( not string ) but that's still only around 1/2 moa . With the equipment and my abilities that's about as good as I can consistently shoot . I mean I have some incredible one off groups I've shot that were just a hole in the paper with only the outer edge showing the curve of a couple of the 5 of 10 bullets fired but that's not the norm .
Here's what I have so far , I did not finish all the data but all the relevant numbers are there . I could not get the spreadsheet to upload so I took a picture of a printed copy 
There are a couple things to note . Each individual lot/headstamp were sized to the same length from head to datum using my Hornady gauge Bumping the shoulders back .002 to .003 depending on the headstamp . How ever I only used a Body die so the necks were not sized down or expanded and are the exact same diameter as they were when measuring the fire formed section .
ALL MEASUREMENTS ARE IN GRAINS
There are a couple things to note . Each individual lot/headstamp were sized to the same length from head to datum using my Hornady gauge Bumping the shoulders back .002 to .003 depending on the headstamp . How ever I only used a Body die so the necks were not sized down or expanded and are the exact same diameter as they were when measuring the fire formed section .
ALL MEASUREMENTS ARE IN GRAINS
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Agreed as far as consistency . How ever it's been rumored that Fed brass is soft and does not last as long as lets say Lapua so the lupua brass although slightly less consistent may in the long run be the better brass to use .
I'd also like to point out that my calculation of the fire formed Fed GMM capacity ES is wrong . The correct ES should be .8gr
The one thing I'm happy about is I ran this test a couple years ago with the LC-14 , LC-12-LR and Lapua brass and all the numbers from the last test matched this recent test to with in .1gr and that's different pieces tested as well .
I'd also like to point out that my calculation of the fire formed Fed GMM capacity ES is wrong . The correct ES should be .8gr
The one thing I'm happy about is I ran this test a couple years ago with the LC-14 , LC-12-LR and Lapua brass and all the numbers from the last test matched this recent test to with in .1gr and that's different pieces tested as well .
Hope that data helped , it did me or at least confirmed what I already knew . I think I'll continue doing my volume test with my fire formed brass rather then sized cases . The theory is that fire formed brass from a specific rifle represents the actual available space for powder as it builds pressure . Quick loads wants fire formed case capacity to calculate it's data . I have to assume that's because not only does every die size cases different . Each reloader sizes there cases to different specs . Leaving the fire formed cases as being the only truly consistent capsule from which to get the measurements from .
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What I did not expect was the difference in capacity extreme spread for fireformed and FL resized to be that much different (0.56 and 0.89). I expected a little bit less for fireformed because the wider the case the less significant the wall thickness to the total volume, but not that much. The GMM has the most difference and Lapua the least.
No but only because that would take me a really long time to finish and I already have good loads using all that brass . The issue with the loads already worked up is that none use the same components . Generally I pick a case/headstamp and dedicate the components to that case
What data or results were you looking to get . I keep pretty detailed load data notes , maybe I have what you're looking for .
I don't remember if I mentioned it earlier but think I did . The Lapua , LC-14 & LC-12-LR all were fired from the same Savage model 10 while the Fed GMM were fired from my Ruger PR . The Ruger has a shorter headspace but larger diameter chamber then the Savage . My savage cases will drop into a case gauge but the Rugers will sit up about 3/8" and I bump the Ruger shoulders back .0015 more then the Savage when bumping .002 from fire formed . I could feel these differences when sizing all these cases . I used Hornady's Unique sizing lube but could still tell the Fed cases body's were being sized down a tad more based on the force needed to size them . Maybe not even the force but the feel of it really . It was like I could feel the friction between die and case body when sizing . The Fed cases being fatter when fire formed is likely the difference why you see that large of a variance since all cases were sized with the same die .
Correction
I was just in my reloading room and just by chance dropped one of the body only sized Fed GGM cases into my case gauge and it still stuck out of the gauge 3/8" .
Then I remembered the necks were never sized . It appears the resistance I wrongly assumed was body interference is actually neck interference in the gauge . This then does make that variance UN talked about interesting . Maybe the Fed cases are a tad bit softer and size down easier with less spring back ?????
I was just in my reloading room and just by chance dropped one of the body only sized Fed GGM cases into my case gauge and it still stuck out of the gauge 3/8" .
Then I remembered the necks were never sized . It appears the resistance I wrongly assumed was body interference is actually neck interference in the gauge . This then does make that variance UN talked about interesting . Maybe the Fed cases are a tad bit softer and size down easier with less spring back ?????
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That would never happen top me; I do not have case head space gages because my cases do not have head space.
And then? I do not confuse my gages with other gages. I have case gages, I make case gages I have chamber gages.
And then there are those that confuse the function of gages. If you are using a case gage you should know the case gage measures fired and unfired/full length sized cases.
I suggest you forget the gages and start painting your cases; after an attempt to chamber a case look for scratches.
F. Guffey
Testing the primers
The other day I finally got around to putting all those cases away that I used for the case capacity test . I got to thinking if by using new primers in the cases to seal the primer pockets . Did the water used in the test to fill each case damaged the primers ? I went ahead and pulled 5 random cases from the 44 tested and tried to discharge them in a rifle . All 5 went bang which I thought might be interesting to note here . I assume that the primer pocket being sealed and the flash hole being small likely did not allow water to get into the primer area do to surface tension . I did use some dish soap to reduce surface tension but did notice some when running the test .
The other day I finally got around to putting all those cases away that I used for the case capacity test . I got to thinking if by using new primers in the cases to seal the primer pockets . Did the water used in the test to fill each case damaged the primers ? I went ahead and pulled 5 random cases from the 44 tested and tried to discharge them in a rifle . All 5 went bang which I thought might be interesting to note here . I assume that the primer pocket being sealed and the flash hole being small likely did not allow water to get into the primer area do to surface tension . I did use some dish soap to reduce surface tension but did notice some when running the test .
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I believe it may be Unclenick who has a really good drawing of a primer. This link shows a good rendition of a primer. Primer manufacturers call it a "foil disk" and it offers protection for the priming mix. You can literally submerge primers in a glass of water, dry them out and they will go bang.
Ron
Ron