9mm Brass, Dies, And Bullet Set Back

[2cats]

I have a lot of Federal 9mm brass that came from American Eagle ammunition. It is now thrice fired. The bullets involved are 147 grain West Coast round nose. Dies are Dillon and an RCBS micrometer seating die.

I loaded up four magazines after recording each COL, hand chambered the rounds, hand ejected the rounds, and measured COL again. They shortened (from 1.130") between 15 to 35 thou.

Dillon sent me a new sizing die. I repeated the experiment and the rounds shortened from about 10 to 15 thou.

Repeating this experiment with twice fired Winchester brass, the rounds only shortened by up to 2 thou.

Federal brass does seem to go through my 650 more easily than Winchester.

(At first surprisingly, Winchester case rounds chronoed 17 fps faster than the Federal case rounds. I rationalized this by thinking that the same looseness that allowed the rounds to set back, allows them to begin to move forward more easily, so that less pressure is required and less pressure - and therefore, less velocity - is built up.)

(Also and still surprisingly, the Federal case rounds most often give single digit standard deviations for 18 shot strings - as do the Winchester case rounds. But I would have thought that the set back would be variable enough to increase the standard deviation. Apparently, everything is coming out in the wash.)

I do not know how either of these samples of brass were performing on previous loading cycles. I've just noticed this problem now.

Some of my primers look a little flattened. I don't know how to interpret this when they rounds feel, sound, and chrono so consistently.

1) Have other people observed such behavior?

2) Is this likely related to the age of the brass, or would you expect that new Federal and new Winchester (or brands X and Y), would perform like this?

3) Is this a simple fix for the EGW undersized sizing die? Will the Winchester brass be very difficult to get through an undersized die?

4) Is this a simple fix if I purchase Starline? I was told that Starline is very soft and goes through presses easily, and might therefore behave as my Federal does.

4a) Or should I buy new Winchester?

5) How else can I avoid this problem and continue to use the supply of Federal brass that I have?

Many thanks,

2cats

[snokid]

play with the amount of crimp you put on the rounds.

if you crimp too tight then you will crush the lead and brass, but the brass will spring back and the lead won't.

if that still doesn't fix it....

try

take the expander funnel and chuck it up in a drill press and with 600# emery cloth reduce the size of the sizing portion of the funnel.

I don't think it's the brass that is giving you fits.

Bob

[2cats]

Forgot to mention crimp. It is 0.376 or 0.377". I don't think that this is too much crimp (i.e., too small a measurement). At 0.378", you have a readily discernable (visually and to the touch) ledge that is the case mouth, more than factory ammunicition and enough to make you worry about feeding (it does feed).

Maximum is of course 0.380". Bullets are 0.3555", and Federal brass is about 10 or 11 thou thick. So crimp should be about 0.3555 + 0.010 + 0.011 = 0.3765, which is where I'm at. The Winchester brass measured maybe 1 thou less, and so one could say that those cartridges had 1 thou "less crimp" than the Federal cartridges, but I'd be surprised to see that the tendecy to set back was that sensitive, and vide infra for more data on the two samples of brass as a function of crimp.

At 0.376" the case does not look crimped in. Some factory Federal that I have is crimped at 0.375".

Other tests that I did involved loading dummy rounds in both brands of brass, crimping some and leaving others uncrimped, then pushing them against the bench. Federal set back 10 and 5 thou, for the crimped and uncrimped, respectively; Winchester set back 0.5 and 1 thou, respectively. So the Winchester still performed better regardless of crimp.

Besides, I've got Federal brass behaving differently than Winchester brass, with the same crimp, in otherwise identical cartridges - so why would we say that it's not the brass (or at least some of it)?

Is shrinking your expander funnel preferable to an undersized sizing die?

[TRG65]

I use federal, winchester and whatever other brass I can get my hands on, I've never had any problem.

I have used WCG bullets without problems. Although I will caution that with plated bullets excessive crimp will cut the plating and the plating can then peel off and build up in the chamber. This is bad juju.

I try to set up my 9mm bullets for a .002-3 crimp. Case mouth on a loaded round measures about .377 (if memory serves, it usually doesn't).

Personally, I use Redding Pro(gressive) Series sizing and crimp dies and a Redding Competition seating die. No U or FCD. Before that I used RCBS, I needed to use an FCD.

Between the sizing die and a very small amount of crimp I have not had a problem with setback.

Do you have your sizing die screwed down to touch the shellplate when the ram is at the top of the stroke or bottom if your using a 1050? That might make a difference, but only a small difference.

When you are belling the case, what is the case mouth measurement you don't need alot of flare? Again if memory serves my 9's flare to about .383

If I only crimp to SAAMI or .001 then I will get a slight amount of setback, but with .002 or 3 I don't get any.

Instead of going with a U-Die you could use an FCD.

Take this opinion for what it's worth. As you are finding, different dies have different tolerance. I personally use Redding on everything I care about.

[Patrick Sweeney]

If memory serves me right, I crimp to .372"

You expander is the culprit. It doesn't matter how tight your sizer sizes to, if the expander opens it back up afterwards. Polish the expander down and try again. If your cases do not exhibit a "coke bottle" look from the bullet being stuffed in them, then your expander is too large.

[snokid]

The "u die" or fcd take care of other dies that when they are properly adjusted, still don't size far enough done the case. They miss the "glock" buldge, and what they do by two different methods is to size down farther down the case. The die has less flare to it allowing it to size farther down.

the expander funnel then opens up the mouth of the case and flares it to accept the bullet. If the expander portion of the funnel is bigger than it needs to be the there isn't enough neck tension to stop bullet setback.

The flare you need is only enough for the bullet to slip into the case without shaving off the copper. If you over flare all you are really doing to a point is to stress the brass.

now the crimping die really only needs to smooth the case back out (take the flare out).

The Lee fcd does a full lenght resize along with the crimp, just like your sizing die without the decapping pin, but since the bullet is already seated it doesn't have to have much flare to it.

The different wall sizes of brass will not really be an issue if all the above steps are done correctly. yes thinner cases will get crimped less, and thinner cases will also not have quite as much neck tension, but in a straight wall pistol case, won't be any thing to worry about.

That's not to say there isn't brass that you want to shy away from. S&B come to mind for me, but it isn't because of neck tension, it's because of primer pockets.

Bob

[2cats]

My sized case is about .372 - .373; belled, it is about .388 - .389. This is less than the 20 thou recommended in the 650 manual, and exactly the 15 to 17 thou minimum that Dillon recommended to me on the phone to ensure consistent powder throws.

Correction: I got RCBS and Redding confused; my seating die is the Redding Competition die with the micrometer.

HighTechRedNeck: when you say a crimp of 0.002 - 3, I assume you mean down from the maximum of 0.380, to give you the case mouth dimension of 0.377, which is at most 1 thou greater than mine.

The seating die is all the way down.

So you're saying that if you crimp only to a case mouth of 0.380 or 0.379, you get some set back, but at the 0.377 you cited you don't. And presumably, if you crimped down much further than 0.377, you would once again get set back from the over crimping that is always talked about.

Patrick - your .372 is about the tightest number I've heard. If your not getting any of the problems that people talk about from over crimping (accuracy, set back) at level, I think we can be fairly sure that I am not over crimping.

Your argument about the expander undoing the work of the sizer certainly makes sense; I hadn't thought about that. Both the Federal and Winchester rounds appear coke-bottled.

By the way, when I switched to Winchester brass, I found that my COL had increased by about 5 to 7 thou, and I had to change my seating die setting.

Doesn't someone from Dillon hang out here? Would you folks be willing to take a swing at this?

Thanks,

2cats

[EricW]

Viable solutions:

- Reducing the OD of the expander funnel

- Lee "U" die in the sizing station

- A surplus Non-Dillon 9mm sizing die may possibly work as well. I've found Dillon dies to land on the high side of the tolerance band.

Poor/Non-Solutions:

- more crimp

- Lee FCD (a band aid at best for bullet setback)

[ErikW]

Crimp is a crock! You've got problems if you are trying to hold the bullet in the case with crimp. Just ask the star of the Competition Reloading video:

removing the flare and returning the case mouth to it's original dimension

[2cats]

Erik Warren,

I'm not sure exactly where you're coming from with the "crimp is a crock". I never meant to suggest that I was attempting to hold the bullet with crimp; I understand well that case tension should hold the bullet, and I believe that is where my problem lies - the relative case tension of the Federal cases vs. Winchester, in my reloading set up.

I think most of the information I've presented supports the contention that I am not over crimping - but I'm going to read you link now.

[TRG65]

2cats,

I didn't have problems with set back if I crimped more than .377, I started having problems with the plating getting cut, this caused accuracy/tumbling and copper build up in the chamber, but it never caused setback problems for me.

I switched from plated to jacketed to eliminate the problems I was haveing w/ plated bullets. Also having just ordered 40K of the JHP's that I shoot, I won't be going back to plated anytime soon.

I understand that the crimp should not be necessary to hold the bullet in place. None the less, when my presses are set up to give consistent throws I have found it to be required. I use the "push" test. I put the bullet vertically on the bench and then push on the primer end as hard as possible with my fingers trying to drive the bullet into the bench. If there is any set back I tighten the crimp die a little and try again. I also rarely end up with "coke bottle" rounds. I guess I need to polish my expander also. I've always used it just as it came from Dillon. I assume it should just be polished on the straight portion before the flare? Does anybody grind before polishing?

[ErikW]

Have you measured a sample of bullets? A .354" pill could allow setback. Maybe the Fed-Win case difference is just enough to stack the tolerances.

If the bullets pass muster, I think the thing to do is polish your expander. If that doesn't work, ditch the problem brass or get an undersizing die.

I wasn't accusing you of overcrimping, just cautioning you from going down that path. And I was expressing my general dissatisfaction with the word crimp.

[2cats]

The bullets appear to consistently be 0.3555". I guess I'm at the point where, pending some input from Dillon here, or a phone call to Dillon, I'm choosing between the U die and polishing the expander. I'd hate to think that I've got to chuck all that brass. I would guess that "softer" or "more ductile" brass would last longer, and it sure is easier to work through the press.

What about Starline?

I also dislike the word "crimp".

[Carlos]

Eric wrote" "Crimp is a crock! You've got problems if you are trying to hold the bullet in the case with crimp. Just ask the star of the Competition Reloading video"

Amen brothers Eric and Brian! About every reloading manual out there need to be re-written and the word "crimp" needs to be limited to Revolver ammo (where there is an actual crimp that does hold the bullet in place). WHen it comes to autoloader ammo, I have long believed that you can "adjust" crimp in only by changing the sized diameter of the case; i.e., achieving the classic "coke bottle" shape. 2 Cats: don't pitch the brass; it sounds like you are on the verge of solving the problem; there is plenty of good advice in this thread. Regards, C. (aka Carlitos, TY44934, CBR600).

[Flexmoney]

"Crimp" has little to do with what we usually load.

[2cats]

Just got off the phone with Dillon. They felt that polishing down the expander/powder drop die would not be a good fix, because they size this a couple of thou less than the bullet diameter to begin with. A crude caliper measurement while on the phone confirmed this - it was about 0.353.

He also wasn't keen on a Lee FCD; don't really recall the rationale, but I think it went along the lines of "if it sizes down the case with the bullet seated, it can't be good for the bullet".

First choice was an undersized sizing die. The EGW die - is it Dillon compatible, in the sense that it is a combo sizing/depriming die? And is it carbide?

[ErikW]

> First choice was an undersized sizing die.

[gomer] Surprise, surprise, surprise! [/gomer]

> The EGW die - is it Dillon compatible, in the sense that it is a combo sizing/depriming die?

Oui.

> And is it carbide?

Si.

http://www.egw-guns.com/parts/parts_dies.htm

benos, you really need to carry the EGW die or something. (Seriously, call up George and license them or something, call it the BE Cure-All Sizing Die.) And we really need to bolster the FAQs on the subject.

Edited January 23, 2004 by Erik Warren

[2cats]

Merci.

Grazie.

Let's hope we're right. If we are, it looks like I'm going to have to take a 0.1 grain out of all my loads (I'm one of those IDPA wusses that's bent on hugging power factor).

For the second year in a row, I am plunged into a turbulent vortex of reloading variability, right before el matcho grande (S&W Winternationals; I refuse to call it the "Winter Championships"). Last year, the sd of my 5.1 gr W231/230 gr load suddenly sky rocketed as my Winchester brass entered a new generation. I had to increase the charge 0.1 gr, which never makes me happy, and I hated shooting it, because I could feel the variability. So a week before the match, I was picking the high primers out of my Fiocchi brass reloads.

While I'm typing - how is Starline?

Vie getez inen, heisen ze frauline Huber?,

2cats

(one day of German in college)