Which 7mm08 brass has the largest capacity?

[Fordnutter]

Has anyone measure the various brands of 7mm08 brass to see which has the largest internal capacity? If 308 brass is anything to go by Winchester seems to be the largest internal. Any experience with this - I guess I might just have get my hands on some various cases & start weighing.

 

[bheadboy]

i have a post where r/p brass weighed more than ww and yet the rp had higher water volume, the density of the brass alloy can cause weight differences thus weight is not the controling factor.
check water volum in a fired case unsized, trimmed to same length and you will get the accurate answer
Bob

 

[4xforfun]

I would be WAY more concerned about case quality than powder capacity. A slightly smaller, better quality case will yeild you more FPS than a poor quality, bigger case before you see any PSI signs.

Just my .02.

 

[dennisinaz]

Palma brass necked down???

 

[louielouie]

FWIW, my necked-down Rem 7-08 brass for my 260 Rem after full-prepping & fire-forming is about 55.6 gr of H2O. The necked-up Win 243 brass after full-prepping & fire-forming is about 56.0 gr of H2O. Definitely makes a difference and QuickLoad shows about 0.5 gr difference is charge weight to achieve the same results - I use the Optimum Barrel Time as a constant.

 

[Fordnutter]

Hmmm thanks for all the information guys. I'm currently using necked down Lapua 308 palma brass with the small primer pocket. Reason for asking is that I'm starting to struggle for case capacity with the slow burning powders : guess that's why they created the 284 Winchester ;D

 

[bheadboy]

there is not a reason to stay with powder that are too slow for the chamber/case you are using, move upin the powder spead range.

Bob

 

[Fordnutter]

I prefer to use ADI powders (Rebranded Hodgon) where possible. I'm shooting the 180gr Berger VLD - Varget gave disapointing speed, H4350 & H4831SC both gave 2,600 fps from my 24" barrel. Problem is that even though I run a very long throat (OAL 3"+) I'm having to compress quite heavily. Ive tried reloader 17 which gave decent velocity & accuracy but I found it to be very temperature sensitive in testing. I was hoping that brass with a larger capacity might allow a little more breathing space so loads weren't so compressed - I'm struggling now to maintain a consistent OAL due to this. Ultimately turning it Ackley improved would solve this or the good old 284

 

[fguffey]

“I have a post where R-P brass weighed more than WW and yet the R-P had higher water volume, the density of the brass alloy can cause weight differences thus weight is not the controlling factor.
check water volume in a fired case unsized, trimmed to same length and you will get the accurate answer”

I will not take your word for it, WW, Winchester Western, WCC, Western Cartridge Company, Winchester, WRA have one thing in common, Olin.

I do not sit in front of a mirror when reloading, that would be ‘so vain’, as to difference in cases, most reloaders have a repertoire of phrases that they repeat over and over and over, then? as someone must have said they began to believe it after it has been repeated enough times. Commercial R-P 30/06 cases have case head thickness of .260, LC, TW, DM etc., have a case head thickness of .200 meaning the case head thickness of the R-P is thicker than the military surplus case head by .060 thousands YET! it is claimed the surplus military case is heavier because it is thicker??? and that is the reason I say a lot of this stuff is just made up.

Thicker/thinner? Heavier? Deductive reasoning? If the surplus case is heavier with a thinner case head the case body is thicker, and does that make a difference? Yes, the column of powder inside the case is effected, the 30/06 powder column in a surplus case is longer (because of the thin case head) and smaller in diameter because the case body is thicker when compared to the R-P 30/06 case, because, the thick case head shortens the powder column and because the case is lighter than the military case the R-P case body is thinner, the powder column is larger in diameter, if that sounds familiar, think about it, the 308 W has a short powder column that is larger in diameter than the 30/06 powder column, BUT!? Who measures and weighs.

I have been accused of doing some ‘risky stuff’, when choosing a case for ‘risky stuff’ I choose the R-P case that is .260 thousands thick over the military case head that is .200 thick because of case head protrusion with heavy loads, I want all the supported case head I can get, the difference between military and commercial case head support could be .135 thousands for R-P and .075 with military surplus (less the radius).

Case head thickness, think, think of all the bent anvils RCBS has replaced because of the lack of discipline among reloaders that do not weigh and measure, rendering parts of the RCBS primer pocket swage scrap is a results of a failure of the reloader to sort brass by case head thickness.

F. Guffey

 

[Fordnutter]

Interesting - which probably brings me right back to the current case im using - Necked down Lapua 308 Palma small primer pocket brass with plenty of thickness in the case head / web area. I certainly seem to be able to run quite stiff loads without loose primer prockets rearing their ugly head.

 

[Dans40X]

I use Remington URBR small primer pocket brass for all of the 308 family case forming-.243,.260,7mm-08,.308,.358 in bolt guns.
In gas guns,I run R-P or 2 decade old Federal.

Winchester/Mil Spec brass is used in winter months,so once it clears the ejection port it served it's intended purpose.

The B.S. that mil spec brass is heavier/thicker than commercial brass went by the way side in the '70's,but is still preached/believed to this day.

Check your components!!

 

[fguffey]

Think about it? Just an observation, but, when compared to other responses it would appear I was/am the only person that put any thought into their response. Again, deductive reasoning? The case is heavier, therefore; the case is thicker? Still, that could be a half-truth. And, again I ask, Who measures? Who weighs?

Think about it? On the way to check out the possibility of getting a bargain on components with a friend, we discussed his need for another case cleaner, he then explained to me why he purchased a Hornady ultra sonic case cleaner, I did not make an attempt to talk him out of purchasing the tool, I did ask about capacity and time and consumables and he never explained to me why he just had to have the cleaner, until, finally, it arrived. The last case cleaner project I helped him with was a variable speed, chain drive, 30 gallon stainless steel concrete-mixing/looking machine, and it is fluid/or media compatible, 600 hundred 30/06 cases+++ at a time, before that? There is not a case cleaner he does not have, now he has the Hornady ultra sonic, because he builds rifles that shoot one hole groups, he makes bench ‘resters’ look good, then the problem, the necks, the necks of the fired cases, the necks are not easy to clean, he knows the fluid/stainless what ever is going to clean the necks, he needs special HEAVY? water, but, already he is disappointed with the capacity, the capacity is going to slow him down, and already, he is not all that excited about about hovering over this little bitty case cleaner, seems he is spoiled, he is used to sticking his head in the tumbler drum, hollering and getting an echo.

Think about it? He opened a crate of 500+ 308 W fired cases, sure enough all the neck were black, and I said “time is a factor”, he then explained the amount of effort required to clean the case necks, I then ask for a dial caliper, he told me what the dimensions were, sure enough, he was correct, but the case neck diameters, to him, the neck diameter variation made no sense, some were 3.445, others were 3.335 and others were in-between. Then I measured the case head thickness, on a + or – bases the case head thickness was .015 thousands, The thickest case head was .230, the thinness was .200, All 500+ cases were MATCH, I do not know what the cases matched, I only know the cases did not match each other, I measure before and after.

I did not have to think about ‘it’, I have offered to improve the fit between the case neck and chamber neck, but, when keeping up with more than one thought at a time I will consider case head thickness, weight and the length and diameter of the powder column, with his big barrel 308 rifles I will not expect improvement, after all, how does one or two improve on ‘one hole groups’. The dirty necks bother him.

In the 60s there was an article about a reloader/shooter, he purchased 500 cases from the same lot, he sorted, measured and weighed and shot, then measured, sorted and weighed, rotated/indexed to determine if the powder column was centered then indexed and shot again, anyhow, out of the 500 cases from the same manufacture/lot he sorted out 45 cases that were were capable of shooting one hole groups, the rest he found to be predictable, some to the point he had to index the case in the chamber.

F. Guffey