Brass Experiment

[MustangGreg66]

Well of course it's not all really made equal and yesterday I set out to see just how unequal .40 brass really is. I took 10 rounds of every diffrent type of brass I had (and fewer rounds where I didn't have 10) and loaded them all with the same powder, bullet, seating depth, primer, and even loaded them all in the same sitting. I took them to the range yesterday and shot them off the bench through a cronograph set 10' from the front of the bench to get the data. I put it all into excel and this is what I came up with.... well somehow I had to dump it into a word doc to attach it here, but that works too....

40CaseExperiment.doc

So after doing all this I'm left with some questions that may be personal for each loader, or may be standard for competative loaders. What is a good standard deviation for a load. The lower the better but at what point is it good enough? Same with the extreme spread, what's acceptable for a match load VS a practice load. These are the two items, as well as the power factor, that I used to evaluate the consistancy of the load. I figured since PF is a factor of the velocity, then diffrences there would be a good measure ofwhether or not the cases are making the same pressure/velocity as others.

I've concluded for my own use that:

--Federal brass, PMC, Fiocchi, IMI and ELD were inconsistent since they had a SD over 10

--All the Nickel brass was very close in spec, even the Speer (which I personally don't like the look of). If anything the Winchester-Nickel was more out of spec and that's probably because there were some few really old looking cases in there

--Winchester and RP brass were very close to eachother.

--G.F.L., Win NT, CBC, CCI-Brass, Starline, Speer-Brass, and *I* were all very consistant withthe lowest SD of any of the brass. Good stuff for sure.

Some Loading notes:

--G.F.L. and IMI were both tight in the dillion powder tube, sticking in the tube when the ram was lowered

--CBC had nice tight primer pockets

--Win NT had some lose primer pockets

--Speer had tight primer pockets but took more effort than the others to size

So I'm pretty much set on doing what I was going to do before and mainly shoot the Nickel plated stuff in matches and even practice (since I've got a bunch) and I can have piece of mind enough not to sort them since they're pretty darn close. As for the non-nickel stuff, I'm happy with most of it. I'll still weed out FC cases, which aren't on here anyway since most people say to toss them, and I've only come accross one from all the brass I've scrounged. Also I'll be putting PMC, ELD, IMI, and Fiocchi into a batch that I'll just shoot once and leave. Federal wasn't to far from the rest, but far enough for me that I'm going to sort out the brass and give it it's own batch. I'll probably use it for more informal shooting as well.

Just a note about the velocity. I am loading 3.3gr of clays so I can have a light load to shoot my G35 in Production. When I loaded lighter, the slide stop stopped catching on the last round for some reason, maybe my grip had something to do with it too, but afer doing this testing I realized I'm getting a lot more velocity than I thought. I'll be adjusting my load to something like 3.1gr and going with a lighter recoil spring to bring the power factor down.

[Guy Neill]

While we all make much about small standard deviations, there have been times when ammunition showing fairly high deviations still turn in the best accuracy. As such, the bottom line criteria should be functional reliability and accuracy - with the one caution that if the extreme spreads can drop you into Minor (assuming you're trying to stay in Major) then that may not be the best load.

There are so many variables that it is very difficult to pin things down too exactly.

Realistically, none of the deviations in your chart look all that outrageous. As I recall it was the gun show Remington that gave the highest extreme spread, but that doesn't rule out that it could deliver good accuracy.

The bottom line is that you have to decide what you can live with.

Very often the evaluating factor for cases is the consistency of weight. Even so, variations in temper or work hardening can produce varying results when shooting.

But such comparisons are always interesting, and do teach us stuff.

Thanks for posting your results.

Guy

[revchuck]

Thanks for posting that. I know it was a lot of work, and the results are interesting.

I think you're too worried about SD. The highest SD you show (16.43) would still be considered well within the acceptable range for factory ammo. Then again, we all have our things we worry about.

I use SD to ensure my ammo makes the PF - IIRC, loading to average velocity plus 2xSD gives you a 95% confidence factor that you'll meet the PF; for example, if I load 158 grain bullets to minor (793 fps required) using a load with your 16.43 fps SD, I'd make sure that my rounds averaged at least 826 fps (793 + 33). This way I'd be reasonably sure that 19 out of 20 rounds would be above the minimum velocity needed. (I used 158 grain bullets because I worry about this most with .38 Special.)

"FC" and "Federal" aren't the same brass, though they're both made by Federal. The original (1990-ish) Federal .40 loads were loaded in "FC" brass, and there were documented instances of this factory ammo KBing. That's the brass that everyone agrees should be recycled rather than reloaded. "Federal" brass, OTOH, is the redesigned stuff that's strong enough to use.

[JThompson]

That's interesting... and could come in handy for chrono too.

[Throwin Lead]

All in all your results of all brass used looks very consistent. Keep all the brass you have. The subtle differences in them are really a mute point.

I would not hesitate to use any of the brass tested for practice or match ammo. Some variables to consider regarding your tests are powder throw/powder metering variations, consistent strokes of the press assuming you loaded on a progressive press, slight deviation in OAL and the variation however slight of case volume from one case to another in relationship of how the powder sets under the bullet.

In my experience with Clays loading 40 for minor at 3.0 gns there can be subtle variations in metering - maybe as little as 0.05 to 0.10 per charge in a batch run of several hundred rounds. Does that make it a show stopper - absolutely not. I think for the game we play accuracy and consistent velocity are the key. To me the ES compared to the average velocity is the deciding factor. If at a match and 3 rounds are shot over the match chrono from the value of the average velocity minus 1/2 of ES will it make the required PF? Obviously one would want as small a value of ES as possible.

Using values from your document for Winchester brass: 803 - 13 = 790. 790 x 180/1000=142.2 PF

If at a major match and the ammo sent to chrono produced velocities in the 790 range you would safely make minor PF.

Thanks for sharing your results. This entire testing process took a trememdous amount of effort to do.

[Graham Smith]

Thanks for the info. You have really got me thinking about something that I need to pursue. We make a lot about the ES and SD of the FPS, but what about the ES and SD of the PF? It seems to me that this might be a better indicator since it is the PF that we are ultimately interested in rather than the raw FPS.

I have a computer program setup to store my chrono data, I think I'll add in these calculations over the weekend and see what it tells me. Probably it will tell me that I'm being too fussy about things again, but...

[Bill Nesbitt]

Thanks for sharing. I load 38 special and have also found that Wincester brass shoots a little faster than others. That's what I try to use for major match ammo.

[Jman]

Wow. Nice work. I use EVERYTHING except old "FC" in my G35.

Sadly, brass wont fix those mikes I accumulate out past 25 yards.

... or, for that matter the no shoots at 10!

Jim

[MustangGreg66]

Thanks for the feedback guys. And you're all right, I'm probably nit picking too much here, especially when I should be taking the time to practice the fundamentals of the game rather than messing the the load, haha.

I don't know if I stated it before but all the ammo was loaded on a Dillion, with Dillion carbide dies. I think it took me longer to sort through my brass and pick out the cases I needed than anything else. I shot it all in one afternoon and for the most part, shooting off the bench at 25 yards I was able to keep all but a few shots in the black... now if I could only do that standing.

I did a random check at OAL after I loaded and I found some veriation that I wasn't expecting. Some rounds miked at 1.130, others 1.134, 1.132 and so on. I was thinking maybe it was the fact that they were plated bullets, but that shouldn't matter as they were Double Struck and noticably a lot more consistant looking than other plated bullets I've shot. The depth variation I thought might be due to junk building up in the die, but the variation didn't seem to get shorter OAL as the loading continued, it was just irratic. So I'm thinkng perhaps it has something to do with how the case grips the bullet as it's being seated and crimped... I dunno, just thought I'd throw this out there, maybe I'm being nit picky again, but I'd like to have the most consistant ammo I can so that when I screw up on the course I can't blame the ammo.

Worst of all I read about a Kaboom that probably happened because a bullet got pushed into a case, set back, causing a pressure spike. I doubt the variation I'm getting would do anything like that, but it's something to be concerned about.

Out of curiosity, what are some of the OAL variations that you guys are getting? Anyone bother to measure?

[Throwin Lead]

Out of curiosity, what are some of the OAL variations that you guys are getting? Anyone bother to measure?

With mixed brass about the same results as you described I'd say plus or minus 0.003 to 0.005 of my "intended" OAL.

I like to think those values are between 1 or 2 RCHs which is good enough for almost anything man does.

[ben b.]

Out of curiosity, what are some of the OAL variations that you guys are getting? Anyone bother to measure?

+/- .003 is my criterion. Most are < +/- .002.

[fastshooter03]

Years ago we chronoed the different brands we had on hand with same load, oal, blah, blah, etc, etc, and you will notice a velocity difference between the manufacturers of 40 cal brass.

If I remember right winchester gave the highest velocity.

Does Starline make a special(not their standard stuff) 40 brass with less case capacity and super strong web base?

If they don't does anyone else think that would be a good Idea since that may allow for lower powder charges than we are currently using? Since we normally use a longer OAL than the standard why not take up the space with strength. I know there would have to be a big compaign to inform everybody not to use normal load data for it but wouldn't it be worth it?

I only shoot 40 lim/lim10 for fun but I'd like to see it made.

Nick

[photog]

I reload ONLY R-P nickel and still get +/- .002 of intended OAL.

I made a decision to sort brass for headstamp just because it removes a variable, and i get used to looking at only one kind of brass. Makes the sorting/culling go faster, since I only have to compare it to what I KNOW is a good case. The R-P's (for me) work best in my press and I have the fewest issues with them. The nickel is easier to load due to less friction in the die and feeds better for the same reason. Just my .02

Thanks for the info and hard work!!

[Jeff686]

I'm not a statistician, but I did stay at a Holiday Inn last night.

Edited October 9, 2008 by Jeff686

[MustangGreg66]

Wow, nice bell curve and those charts are cool. Thanks

[MoNsTeR]

Interesting results, but the sample sizes are far too small to be conclusive. You can't say "Brands X, Y, and Z are too inconsistent because the SD is over X" because with n=10 (or less) you can't actually be sure the SD is what you measured. A good rule of thumb is to sample at least 30 units.

[G-ManBart]

This is interesting, but it doesn't prove a whole lot. The more times cases get reloaded, the worse your SD will get and, often, the lower the velocity will be. If you compare new brass, that's an entirely different matter and might tell us more.

FWIW, I've gotten the highest velocity in .40 using Win brass. I get a nearly unlimited supply of it once-fired, so it's sort of a no-brainer for me to stick with it. I like the way Starline loads better even though I have to bump the load up, but I'm not buying it when I can get once-fired free.

[shred]

I notice that different lots of brass also change over the years. It's been very noticeable with Starline Supercomp. Originally it had a thin extractor cut like 9x19 .. Now it looks a lot more like TJ at the bottom end. I never checked to see if those changes were internal as well.

[mr renwick]

I notice that different lots of brass also change over the years. It's been very noticeable with Starline Supercomp. Originally it had a thin extractor cut like 9x19 .. Now it looks a lot more like TJ at the bottom end. I never checked to see if those changes were internal as well.

Sorry For the rookie question but what does sd,es and the others stand for?

[kgunz11]

If you used new virgin brass and had 10 of each brand perfectly loaded all within the exact same specs there might be more to your data. You would then be doing a more fair comparison.

I agree with the above poster that said SD and ES don't really mean squat when accuracy is concerned. Where I'm from, we check loads at 1000 yards (rifle) and I can tell you from experience, ES and SD at 12' don't mean much.

Arguably the best long range shooter in the country has a rather unique way of developing his load. He keeps adding powder until he finds pressure then he backs off 0.5 grains. He loads up 10 or 20 of that load and takes it to the range and verifies accuracy at 1000 yards. More times than not he does not dicker with it after that 1 trip. Taking the overall title at Camp Perry the last 2 years in a row tells me volumes!

[kgunz11]

sd = standard deviation

es = extreme spread

[Para 16]

You guys might be interested in the article in this months "Handloader" magazine. Not about pistol brass, but.... Its about 308 loads, shows Accuracy with virgin brass, once loaded and "Brass Endurance Testing" (fired to the point of failure) Good reading, answered a lot of questions. (hmmm... maybe created more questions)