Once-Fired 9mm Brass exceeds SAAMI max length (Federal)????

[Tcruse]

UPDATE:

Federal brass sucks.

I just got through measuring 100 CBC-headstamped units of 9mm brass I picked up at the indoor range where I shoot (this is the brand the range sells, manufactured by Magtech) for purposes of comparison. Of these, less than 10% were over .754" in length, and only two were greater than .755. Compare that to approximately 30% of Federal, which were often significantly greater than .001 over max.

To compare (100-count samples of once-fired brass):

Federal: minimum length: .750, maximum length: .758, average: .7536, case length standard deviation: .0019, average case wall thickness: .0116
CBC (Magtech): minimum length: .750, maximum length: .759 (one), average: .7529, case length standard deviation: .0015, average case wall thickness: .0123

Finally, I checked another 200 once-fired Federal cases for lengths above .754. Once again - approximately 30-35% exceeded .754.

Based on your definition of "sucks" you may be correct. However, unless you can identify a measurable problem with reloaded ammo using this brand, I would have to disagree.
Now, recently, I added a Dan Wesson 1911 Pointman 9 to my stable of guns and found that about 5% of my reloads have a problem. I was using Lee carbide sizing die and had it set to "recommended" values.
By adjusting it to "forcibly" touch the shell holder seems to solve the issue for the most part. The other part of the equation is that most of the brass had been shot multiple times using Glock Gen 2-4 firearms that are much looser in the barrel.
I went one step farther and started using the "U die" from EGW (?) witch is a Lee die manufactured to .001 inch smaller that the normal Lee die. This is 100%.
Depending on the sizing die the length of the case does vary some.
FYI - I also have had no issues with reloading the Federal/CCI aluminum cases. Probably not good for as many reloads but still good for several cycles.

 

[Tcruse]

This doesn't make any sense to me.

If the OAL is a significant factor (due to its relevance to cartridge volume / chamber pressure), then the variance in brass should be equally significant.

If I took the lowest and highest observed lengths from the Federal brass I measured - .750 & .759 - and loaded them to identical OALs, that's nearly .01 difference in bullet seating depth. Would you be happy with .01" setback? Because to my mind there's no difference between the two.

My main gripe with the Federal isn't necessarily it being max SAAMI spec. It's that it's inconsistent in length.

Also - speaking of setback - while I have yet to test it, I'm pretty sure the relatively thin case-wall of the Federal (compared to CBC) should be more prone to such issues. Any additional inconsistency seen as a result would stack on top of the inconsistency of the brass.

I agree that there are likely other factors that have a more dramatic impact on precision than the issue I'm exploring here. But choosing one brand of brass over another isn't a difficult proposition.

Regardless - how can you really tell if the changes you're making are actually affecting accuracy if your component selection is inconsistent. If I load 100 rounds of brass that varies in length over a .01 range, while testing a .01 change in OAL... will my results be meaningful?

I think the issue with pressure is the "size" of the area that contains the powder and not OAL. OAL is just the easiest way to control/measure seating depth. OAL certainly is also an issue with some magazines and chambering.
My first question would be does the differences in the "bottom" shape and thickness of the base of the case on the inside not vary more than the numbers you are seeing?
In my experiments, the problem of bullet setback is always a case sizing issue and not case wall thickness.
I do not think that we can judge the quality or pressure handling properties of a give case (or brand of cases) based on case length or wall thickness without a lot of other factors that are difficult for most of us to measure.

 

[mdi]

While this thread is interesting, much too much emphasis is being placed on 9mm case length. I, like many, many others do not measure handgun cases and we have fired millions of reloads without knowing how long the cases are. I use the "Plunk Test" and have never had a problem with a WWI design pistol, a modern design plastic pistol, or a brand new pocket pistol. I understand "I just wanna know" but after a while of tossing theory around it gets to be "much ado about nuttin"...

 

[azrocks]

My first question would be does the differences in the "bottom" shape and thickness of the base of the case on the inside not vary more than the numbers you are seeing?
In my experiments, the problem of bullet setback is always a case sizing issue and not case wall thickness.
I do not think that we can judge the quality or pressure handling properties of a give case (or brand of cases) based on case length or wall thickness without a lot of other factors that are difficult for most of us to measure.

I agree that I don't know how or to what extent case-wall thickness matters. This is a variable I'll be testing in the near future.

I do, however, believe that in addition to the volume / pressure changes caused by loading different-length cases to the same OAL, there is likely also an impact on bullet setback, as differing case lengths will cause more or less bullet surface area to be in contact with the case walls. When you add in the effect of inconsistent bullet setback with inconsistent volume/pressure, the combined effect may be enough to matter. And that's what I'm fixing to find out.

 

[azrocks]

While this thread is interesting, much too much emphasis is being placed on 9mm case length. I, like many, many others do not measure handgun cases and we have fired millions of reloads without knowing how long the cases are. I use the "Plunk Test" and have never had a problem with a WWI design pistol, a modern design plastic pistol, or a brand new pocket pistol. I understand "I just wanna know" but after a while of tossing theory around it gets to be "much ado about nuttin"...

I guess it depends on what you're trying to achieve. I'll admit the rounds will chamber & fire. That's not enough for me at the moment

Regardless, If you're trying to judge the impact of one variable change (like a .01 difference in OAL) you can't have other variables moving at the same time. If I loaded these Federal cases (which vary almost .01 in length) to test a OAL change of .01 (like 1.045 to 1.035), and I see a difference, I have no idea whether it was the OAL change or the variation in case length.

I never entertained bullseye shooting sports, but maybe that's what I'd like best (lol).

 

[ReloaderFred]

Since you're overthinking this so much, and have just started reloading, let's throw another fly into the ointment and you measure the lengths of the bullets you're putting into these cases. You're going to find some variations in those, too. Then weigh the powder charges on a lab quality scale......... You see where I'm going with this?

The people giving you advice have been doing this for awhile. I've been doing it since 1963, and my round count is somewhere over 850,000 rounds loaded. My experience has been that what you're worrying about isn't worth the worry.

Unless you're testing your loads for accuracy in something like a Ransom mechanical rest, or you're a robot, the human factor is going to have more bearing on accuracy than what you're concerned with at this point.

Hope this helps.

Fred

 

[Rule3]

delete

 

[Blue68f100]

If I took the lowest and highest observed lengths from the Federal brass I measured - .750 & .759 - and loaded them to identical OALs, that's nearly .01 difference in bullet seating depth. Would you be happy with .01" setback? Because to my mind there's no difference between the two.

No it will not. You internal volume is the same due to the bullet seated the same OAL. All your loosing is on the outside of the round that hold the bullet, neck tension.

 

[LeonCarr]

I shoot and load a lot of 9mm, and use the Lyman E-Zee Case Gauge on sized brass before loading. The reason I started doing this is because I started having loaded rounds not going flush or slightly below into my EGW Case Gauge. Turns out that all PPU Brass (Prvi Partizan, which also the makes the Monarch Brand sold by Academy) would not pass the E-Zee Gauge and was measuring way over .754, usually .759-.760.

This is the only 9mm brass I have reloaded that is consistently over SAAMI specs and I have had to trim. Never an issue with Federal brass, but YMMV.

Just my .02,
LeonCarr

 

[bullseye308]

I have loaded close to 500,000 rounds of 9 mm since I started in 89/90. I know I measured 50 cases when I started and was told not to bother, as long as they chamber I'm good. I haven't measured a pistol case since, and that total is close to 750,000 in pistol rounds. I think I had what might have been a long case once, but I pulled the bullet and primer and dropped it in the recycle can.

If the length had any factor in the accuracy of the round, it would be so insignificant that only the best bench rest shooters could tell the difference. When I load mine, I grab a handful at a time out of a bucket of prepped brass and load. I don't even look at the head stamps anymore. Yesterday I shot my Range Officer 9 freehand at 25' and got 10 rounds in a 2 1/2" group including a flier. Without the flier it would have been 1 1/2". I did that consistently throughout the day. Few weeks back my groups were .75" at 25' but I bruised my shoulder since then.

New Reloader's stress over many variables that have no benefit(we all did it), until they prove it to themselves. I did it, many others did too. Focus more on doing everything the same way every time, keep good notes for later review, and have fun.

 

[azrocks]

If I took the lowest and highest observed lengths from the Federal brass I measured - .750 & .759 - and loaded them to identical OALs, that's nearly .01 difference in bullet seating depth. Would you be happy with .01" setback? Because to my mind there's no difference between the two.

No it will not. You internal volume is the same due to the bullet seated the same OAL. All your loosing is on the outside of the round that hold the bullet, neck tension.

The internal volume will not be the same.

If you take a .750" case and a .760" case, and load both to the same OAL, the shorter case has the bullet seated shallower, which equates to higher case volume, lower case pressures, and less case contacting the bullet. The longer case has the bullet seated deeper, creating less volume, more pressure, and increasing the surface area of the bullet in contact with the case wall.

EDIT: Nevermind. I wasn't thinking clearly. My apologies.

 

[azrocks]

You guys are surely all right. I'm stressing over variables that will be overshadowed by my own inherent inaccuracy (the shooter).

But as (well) said above, I'm going to have to prove it to myself anyway

Thanks for bearing with me, folks!

 

[Walkalong]

I agree with bds, a .001 longer 9MM case is insignificant.

.01 setback has a significantly bigger on affect on pressure in the 9MM.


A .01 difference in 9MM case length isn't going to affect pressure significantly. A .01 difference in OAL, yes, but not case length, which is mostly just along for the ride. Round fires, case opens up away from the bullet, bullet moves out of the case. The longer case doesn't matter. Assuming it is a safe length and is not getting crimped because it is past the chamber of course.

 

[higgite]

The internal volume will not be the same.

If you take a .750" case and a .760" case, and load both to the same OAL, the shorter case has the bullet seated shallower, which equates to higher case volume.... The longer case has the bullet seated deeper, creating less volume, more pressure, ...

Sorry, that's just wrong. If the two bullets of the same length are seated to the same cartridge OAL in two of your Federal cases, the volume under the bullet, where the powder goes, will be the same, regardless of case length.

 

[Walkalong]

Agreed.

 

[Walkalong]

Thanks for bearing with me, folks!

It's always good to talk things out.

 

[LiveLife]

I'm going to have to prove it to myself anyway

Right on!

Welcome to the hobby of reloading some of us consider a passion!

For me, fussing over the minute details like using .001" larger taper crimp for .356" sized bullets over .355" means a lot.

But ultimately, it will be the holes on target that will be the final judge. While we ponder the theoretics of reloading variables, consistency of our efforts will show as smaller groups on target. So talk (or posts on THR threads) is cheap but holes on target speak much louder.

So load up your test rounds and see if they make a difference on the target and give us a range report.

 

[azrocks]

Sorry, that's just wrong. If the two bullets of the same length are seated to the same cartridge OAL in two of your Federal cases, the volume under the bullet, where the powder goes, will be the same, regardless of case length.

I think I just realized where my thinking was off.

D'oh!

Sorry.

 

[RecoilRob]

Remember too that the 9mm case is tapered and how long it ends up being after sizing depends on how tightly it's been squeezed into that tapered die. Just for fun, if you back off the die 1/2 turn then size some and see if they end up being a wee bit shorter. Even if they've been sized to slightly too long...once they've been expanded and the bullet seated this should shorten them back to where they belong. You might try loading one of the longest ones, then pull the bullet and measure the length again...bet it's a bit shorter.
It's very admirable to be diligent...especially when first starting something inherently dangerous like reloading, so your concerns about the case lengths are completely justified. But as others have said, unless you're trying to load precision target type ammo this level of deviation is well accounted for in the basic design of pretty much every weapon ever chambered for the 9mm.

 

[azrocks]

Thanks again for all the info, everyone! And for putting up with my brain fart(s)! Sometimes the best way to learn something is to defend a losing position. In other words, I learned a lot!

 

[Jim Watson]

Interesting.
Am I going to start measuring the range pickup brass I load for IDPA? No.
I do not recall a 9mm in mixed brass failing the gauge on length. I get some oversize in diameter or burred.
Nearly all that fail the gauge will plunk and shoot, after CFC on the bloated ones.

On the other hand, I once picked up some Hornady .45s that were too long. They were obviously shootable in factory form with jacketed bullet but they would not gauge or chamber when reloaded with cast.

 

[thomas15]

A couple of comments on Federal 9mm brass. I load for a 9mm revolver (S&W 929). This application of course needs to be used with moon clips as the 9mm case is rimless. So, I'm somewhat aware of the extractor groove dimensions of the various makes of brass as the moon clips are secured to the brass in the extractor groove. For that reason I sort all of my brass and keep them separate by headstamp. I sort out Winchester, Federal and then everything else.

I have the best results with Federal brass, followed by Winchester. All of my other headstamps I consider ok for lost brass situations with my auto-loader 9mm pistols. I've never measured for brass length but I case gage all of my finished ammo using either a Lyman or DAA gage. I use an EGW U-die for sizing. Some of my federal 9mm brass has been reloaded dozens of times with no issues.