Military Once fired brass

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Last Post 14 August 2017

CBA Member

GP Idaho posted this 27 April 2017

Hello All: I hope some of you military class shooters can help me out here. I have a lot of military 7.62X51mm once fired brass, Lake City 08 and 09. I full length ressized some of the brass and fired it once (light jacketed loads) The cases are now 2.012 in length .003 short of needing their first trim. On resizing the brass for the second time (using a Redding bushing FL sizer) there is now a bright ring around the cases just forward of the case head. Now usually I would think case head separation coming up here if I saw this but the cases haven't yet stretched enough to need their first trim. Using my Harbor Freight shop saw I opened up a couple of cases and the inside looks like new, no rut on the inside wall at all. My thought is this brass must have been fired in a S.A.W. or such and is showing the rifle equivalent of the “Glock Bulge&rdquofrom an oversized automatic weapon chamber. Should I take the hit and send these cases to the scrapper or can they be safely loaded with cast bullet loads? Thanks Gp

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Starmetal posted this 14 August 2017

Agreed Old Coot. Personally myself I don't do all that. The thing with the one case is all well and fine until you run to the end of the case life and you have to start over with another case!

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Brodie posted this 14 August 2017

Starmetal;

If his SD - standard deviation-- really is between one and two then he has a very constant set up. Any mistakes and or fliers have got to be his fault now. Think about that for a minute: if he has removed all other variation then when all the bullets don't go in the same hole HE is to BLAME for it. I don't think that all that work has done him any great favors.

Given the same load variations in case volume has to effect pressure since pressure and velocity are directly related variations in case volume must cause variations in velocity. How much and how much this effects point of impact I really don't know. Using a single case (ala John Ardito) would certainly eliminate that variation in bullet velocity (probably why John did it that way) if you are personally worried about case variations I would suggest that you copy Mr. Ardito. But, remember if you remove all possibility of random variation then All the Fliers and Bad Bullet Strikes will be YOUR FAULT better be a well grounded person.

As for me I'm just going to keep on fooling around with different cartridges and loads. Although, I may put a Raven's feather in my hat or tied to my barrel. Brodie

B.E.Brickey

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Starmetal posted this 13 August 2017

Well I breifly talked through email with the guy that measures case volume. We're going to get on the phone sometime today. In a nutshell he said it lowered his ES and SD's to low figures. Example: His SD is 1 to 2. Now I'm not a benchrest shooter, but do any of you know what kind of figures for SD they talk about?

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CBA President

John Alexander posted this 13 August 2017

I know that some of the JB benchrest guys worry about and have expensive little instruments to measure the variation in thickness down in the case body. My reaction has always been that if it keeps them out of the bars in the afternoons it could be a good thing.

I agree with David and Jim no use worrying that those fliers are caused by some nit that didn't get picked. Pogo had it right.

John

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Scearcy posted this 13 August 2017

While some still believe indexing cases, weighing them, sorting cases and other such wastes of time (in my opinion), there is little to no discussion on bench technique. You can perform all the rites of voodoo you wish, spending hours upon hours at the reloading bench, but if you don't spend even more time at the shooting bench, well...... you're just wasting your time.

Amen! The most difficult long gun I have ever shot Is a lightweight, rock stock, 7 1/2 lb bolt gun with cast bullets. Keep a log book when you practice. Cut out and save EVERY group. Unexplained flyers are rarely the fault of your equipment, sorry to say. I wasted several years and traded off a couple of good rifles before I learned this.

Jim

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Starmetal posted this 13 August 2017

John let me tell about this other case fanatic. This gentleman would expand his case out to a straight cylinder. He said that the walls are not of a even thickness. Next he would put them in a lathe and make them all the same wall thickness. Next up he would form them back to the way they were and load them. That is a little bit too much for me.

I like what Ed said about shooting the same case over and over.

Ponder this guys. Auto racers cc the volume of their cylinder head chambers in order to get them all exactly the same. It made a difference in the performance of a engine. The internal volume of a case is very related to this theory.

I don't weigh my cases, I do sort them by brand (or brand and year if military), but if I want the most cast bullet accuracy I do weigh my bullets.

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CBA President

John Alexander posted this 13 August 2017

Starmetal,

Thanks for that additional information. Indeed, if almost all the weight variation is in the part of the case hanging out in the air then the weight variation wouldn't correlate well with inside case volume. Good to learn new things. However, if the other part of the case (the part not hanging in air) is extremely consistent in weight then the weight variation in that part would be tiny and cause an even smaller variation in the volume.

I have no problem believing that the weight variation of cases (as long as they aren't from different lots) has no effect on accuracy -- I haven't weighed a case in the last 30 years. What I have a hard time believing is that the volume variation in one lot of cases has any effect on accuracy or anything else -- until I see experimental evidence from a well planned and executed study.

John

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David Reiss posted this 13 August 2017

While some still believe indexing cases, weighing them, sorting cases and other such wastes of time (in my opinion), there is little to no discussion on bench technique. You can perform all the rites of voodoo you wish, spending hours upon hours at the reloading bench, but if you don't spend even more time at the shooting bench, well...... you're just wasting your time.

Some people are just natural shots and I do believe this. I had only been shooting a handgun for about 10 months when I attending my police academy. Most of my shooting had been plinking, with a little bit of small game hunting. Yet I took top honors in the firearms portion of my academy training shooting a 296 - 52X out of 300 and shooting against 53 other cadets. I don't tell this story to brag, but only to illustrate some have natural talent.

However one year later when I started shooting competitively, I learned very quickly that I could not rest on my natural talent, getting my clock cleaned several times by guys that shot nearly everyday. I ended up having to practice about 3-5 days a week for about a year before being able to be competitive. Experimenting with loads did not help at all, only focusing on concentration of technique and learning to zone out all around me made me a top shooter.

While I know the benchrest game and handgun combat type matches are totally different, I really believe that if more competitors would find a load that shoots under MOA and then concentrate all the rest of their time at the shooting bench, their scores would eventually become more competitive.

David Reiss - NRA Life Member & PSC Range Member Retired Police Firearms Instructor/Armorer
-Services: Wars Fought, Uprisings Quelled, Bars Emptied, Revolutions Started, Tigers Tamed, Assassinations Plotted, Women Seduced, Governments Run, Gun Appraisals, Lost Treasure Found.
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Brodie posted this 13 August 2017

John wrote: place. The brass will be tightly pressed against the chamber. The density of cartridge brass varies little, and almost none in a lot of brass. I assume the cases are trimmed to the same length. Therefore, I can't see how variations in case volume wouldn't correlate with variations case weight (although the percentage of variation would be a different number.) The more brass the less internal volume, the less brass the more internal volume. So the statement that consistency in volume is more important than consistency in brass weight doesn't seem to make any sense. The easiest way to check for variation in case volume would be to check the variation in case weight.

I would appreciate it if you could refer me to a report on the actual al testing so the method used to reach this conclusion can be known? Thanks in advance for any documentation you can offer.

I have to agree with John on this, in fact I thought that was why we weighed the brass. Since some brands are thicker than others it is reasonable to expect the interior volume to vary with the weight.

I know that most here shoot one brand of brass and even one lot together, but back when I had started shooting rifle I began to wonder if sorting my cases by weight would tighten my groups. I did so finding a wide variation in weights of 06 brass from Win., Rem., and GI surplus cases which I had. The GI surplus was by far the heaviest, and therefore thought to be the thickest in those days. Anyway, sorting my cases by weight and firing each unit as a group drastically improved my groups ( from 2.5" to 1.5") . Now, I did not try sorting each lot out because the variation within the weight lot of cases was so small and therefore negligible. I never did get that 06' to shoot better than 1.25" with jacketed or 1.75" with cast, both for 5 shot groups, but what can be reasonably expected from a hunting weight rifle with a 4x scope on it.

I think that the entire argument boils down to a Dumbo solution: If holding a raven feather in your trunk helps you fly then by all means do so. I firmly believe in doing what works , even if it seems a little stupid.

PS Back in the early 70,s nobody thought about the extractor groove. Brodie

B.E.Brickey

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Ed Harris posted this 13 August 2017

John Ardito always used one case and repeatedly reloaded it to shoot his record groups...

In a VERY accurate rifle that would be the best way.

BUT, if the rifle of interest won't shoot any better than m.o.a. anyway, it's all mental masturbation.

With typical cast bullet loads in which the powder charge doesn't come close to filling the case, I don't think it matters.

In cast bullet loads I'm more concerned with consistent bullet pull and shot-start pressure, which is affected by bullet fit, case sizing, how cases are prepped and their state of anneal or work-hardening. Cases which have been fired and resized several times act differently than new or once-fired brass or those which have been annealed.

John Ardito did not resize his brass, but used a tight-necked chamber and bullet which "fit" the fired case neck without having to resize it. He also used a compressed case full of powder which provided base support for the bullet in the same manner as if loading black powder.

None of these factors mattered to him. He shot better groups more consistently than anyone before or since...

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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Standard Member

Starmetal posted this 13 August 2017

John I will get in touch with this groups I'm speaking about and particularly the gentleman that cc's his cases. I'll see if I can get some of his records of before (weighing cases) and after (cc'ing cases) and the corresponding group sizes.

I read where a gun industry writer when to the Hornady brass manufacturing plant. The technicia running the machinery wanted to show him something very interesting. He took some cases from line that were totally finished except for the extractor groove and the head stamp nomenclature and weighed them. They were extremely consistant. They he pulled cases from the end of the line that were finished and weighed them. The weight variation was much more, but not real bad. That's showing that weight difference was in the extractor groove and head stamping and that they were working on that to improve those two processes. That John, is where I say weighing cases wouldn't make a difference in shooting them.

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John Alexander posted this 13 August 2017

Starmetal wrote: "Ed Harris, I have a group of friends that are serious benchrest shooters. They talk often about preparing cases to get the most consistent alike cases. They have found out by actual testing that sorting cases to case volume far exceeds sorting cases by weight for consistancy. Makes sense to me because after all the intenal volume of the case is the boiler room and if all cases are the same internal volume, that they would give the same pressures. What do you think?"

I too will be interested in what Ed thinks, but since this is a forum I assume you won't be offended if I give my opinion. The volume of the rifle chamber is constant with the bolt face always in the same place. The brass will be tightly pressed against the chamber. The density of cartridge brass varies little, and almost none in a lot of brass. I assume the cases are trimmed to the same length. Therefore, I can't see how variations in case volume wouldn't correlate with variations case weight (although the percentage of variation would be a different number.) The more brass the less internal volume, the less brass the more internal volume. So the statement that consistency in volume is more important than consistency in brass weight doesn't seem to make any sense. The easiest way to check for variation in case volume would be to check the variation in case weight.

I would appreciate it if you could refer me to a report on the actual al testing so the method used to reach this conclusion can be known? Thanks in advance for any documentation you can offer.

John

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R. Dupraz posted this 12 August 2017

I have seen a weight variation as much as 12-14 grains between different brands or rifle brass of the same cal.

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TRKakaCatWhisperer posted this 12 August 2017

The common easy first sort is by brand. I wonder though, even though it is a 'given' that uniformity in brass is mandatory for high accuracy, I've not seen comparisons of targets. Like 10 shots from brand 'a' vs ten shots from brand 'b'.

Yes, I sort.

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Starmetal posted this 11 August 2017

Ed Harris, I have a group of friends that are serious benchrest shooters. They talk often about preparing cases to get the most consistent alike cases. They have found out by actual testing that sorting cases to case volume far exceeds sorting cases by weight for consistancy. Makes sense to me because after all the intenal volume of the case is the boiler room and if all cases are the same internal volume, that they would give the same pressures. What do you think?

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CBA Member

Duke M posted this 11 August 2017

Well Ric, since I do have the Wilson trimmer shell holder, I think that is a viable solution. I think I'll start setting the offending samples aside until I accumulate a pile, then plan a session of fixing them. Thanks.

Duke

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RicinYakima posted this 11 August 2017

Is anyone aware of a uniforming tool that can "clean up" the dings, burrs, etc. that brass gets from being fired in semi auto rifles?

When I was shooting High-Power, I would tap the case into a Wilson trimmer shellholder. Chucked an RCBS shellholder into the headstock of the lathe, put the base into the RCBS shellholder and turned the lathe on. Just light pressure would burnish the dings back in line while I held the Wilson shellholder. HTH, Ric

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Duke M posted this 11 August 2017

Risking a bit of thread drift, but here goes. I really like military surplus brass but occasionally some has minor imperfections/damage on the rim that cause difficulty when trying to insert it into a shell holder. Is anyone aware of a uniforming tool that can "clean up" the dings, burrs, etc. that brass gets from being fired in semi auto rifles?

Duke