Is 60-88 Es Normal?

[Rikarin]

Argh, help!

One by one, I measured powder on analog scale and load 10 different load 10 each. Every load's ES is like, 60 to bad one is 88! I don't understand. Only difference is brass. Either Winchester, Finocchi, PMC, UMC, American Eagle I collected only once fired out of box in front of my eyes.

9x19, 147gr VV310 or 320 2.9-3.5 with Federal primer loaded with my brand new 650.

Is it normal? If brass is same (I bought pre-primed fedeal brass), what ES I should expect? What elese I can do to make it more even? If hand measured have this big ES, machine measured might have bigger one. Mmm.

Is those questions answere by some manual? What manual is good?

[gm iprod]

Never mix brass, whether by brands, lots, once-fired or new. This is the root of your problem.

Make the ammo in the way that it is going to be made for the shooting you will actually do. If you have a Dillon RL550 (for example) load all the test ammo on that machine using the powder measure set at what you require. This way you are actually testing what you will be making. Not testing one thing then shooting different ammo.

For 9mm I have an endless supply of Speer once fired brass (about 50,000 at last estimate). I clean the cases thoroughly and discard anything I am unhappy with or not that brand. I have nothing against the other brands, I have so much Speer I will stick to it, and I keep them for anything oddball that comes up.

I get less than 30fps ES for 9mm in my Springfield and I struck a good load with 125gr JHP that gives less than 25fps Es in my Tanfoglio. All loaded on my Square Deal with Hodgdon TiteGroup. I have never used N310 in the 9mm but a freind who has gets about 25-30fps Es with 145gr Lead. My 38Super runs less than 20fps ES on new or less than 3 times fired brass. Always the same brand and lot of brass. After three or four firing the ES opens up a little. Accuracy is down but not enough for me to stop using the brass for practice.

I find machine measured powder to be no more or less accurate than scale weighed.

[Skywalker]

Rikarin,

different brass might have negative inflluence on ES for two different reasons:

1. Internal capacity might vary, thus the "boiling room" for powder combustion will be different, leading to different gas pressure curves -> different velocities.

2. Brass lenght might be different. If you have brass that is .75" in lenght, and set your crimp on that, whenever shorter brass mixes in, you'll get a lighter crimp on them, thus the resulting velocities will be usually lower.

Having said the above, I will tell you that I reload whatever comes handy in .40": new, once-fired, well-worn, mixed stamp, you name it I use it. I load N320 with lead, FMJ and plated bullets, and my loads (177 PF) usually average 25/30 fps ES.

I weigh the first 3 or 4 powder charges (as dropped from my 650), then load about 200 rounds without even checking.

I'd advice to start with the following:

- load your test loads in brass of same stamp.

- Have the machine drop the powder for all your test ammo.

- check loaded test rounds for O.A.L.: ES for O.A.L. should be no more than 0.005"

[revchuck]

I use mixed brass for all the calibers I load. I check to find out which brand of brass gives the lowest velocity, and adjust my loads so that that brass makes the power factor plus 5 (as long as the load is safe). The difference in accuracy isn't noticeable for the vast majority of shooters, including me.

FWIW, it's not unusual for FACTORY ammo to have extreme spreads like you had. Such spreads show up most often in Magnum revolver loads (.357, .41, .44).

[shred]

What exactly is this the ES of? The powder charge? The velocity? The OAL?

I'm having trouble figuring it out.

[Carlos]

I do not record ES when I chrono; instead I look at standard deviation (SD) and for the load you are useing (3.2gr of N310 under a FMJ 147 @ 1.155") I get a SD of 6 for mixed brass and 5.2 for single brand brass. This was out of a Glock 17. I loaded the actual ammo that took 2nd place SSP at Winter Nationals match before last & the brass was Hirtenberger L7A2 once fired brass @ aforementioned SD of 5.2. Regards,

D.C. Johnson

[Rikarin]

What exactly is this the ES of?  The powder charge?  The velocity?  The OAL? 

I'm having trouble figuring it out.

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Hm, sorry. Its velocity.

[Rikarin]

Oh, I see. Thank you. Mm. Whoa. That was so informative.

I was trying to narrow down how much powder I should load eventually. I have ordered brand new (Oh, what a treat!) pre-primered Federal brass, and at least I can start from 3 different load.

I can get bucket full of once fired .40 brass in same brand (go to range after police officers shoot) but 9mm is hard to come by and decided to reuse my own by color coding them.

Skywalker That make sense. I suspect some are very long because the press got "stuck" on downstroke and when pulling handle up, it feels like corking a wine bottle. I am guessing this maybe because a long brass got stcuk on powder funnel. Also, it was bad idea to Sharpie all over. Sharpie-ed brass is so hard to crimp.

revcheck I guess I have to do that high and low correation with brass brand next.

gim iprod That totally make sense. Now I am bit worried. I am going ot use 2nd fired (onece I fired with my Glock19 with quite high pressure (primer totally flattend, brass wall visibely fattened). If ammo's accuracy itself is a mess, it would screw my head!!

Carlos I haven't figured out whats SD is yet, therefore not recording

What I noticed measuring by hand is, machine's accuracy isn't as much as I thought it would be. Quite a difference enought to make balance's hand goes almost all the way or down.

I hope at least ammo load nailed down completely next week. Regional match is coming up on 7th!

Thank you again.

[shred]

Thanks. I generally don't worry a lot about ES (or SD-- btw, Excel has a function for that if you've got Excel) if the ammo is accurate enough and over the PF with enough cushion. Rifle shooters probably care a lot more, but a couple inches at 25 yards is about all you ever need for IPSC

I know an ES of 30 can do that, cause I chronoed some like that the other day, and I have an 'accurate' note written next to a load with an ES of 50 in my log

[warpspeed]

Standard Deviation or sd is all you are worried about. Single digit is what you want but < 15 is OK.

[SRT Driver]

Fast powders, light charges, heavy bullets, and lots of air space in the case contribute to high ES.

I use 125 JHP with 4.2 VV N320 and mixed brass as a Production load. It is consistent at about 3-5 SD with ES of 15 or less.

FYI - changing primers in between Federal SP and Win SP = 3 FPS difference, brass = unconsequential.

High ES does not mean inaccuracy..just more sweat at the chrono. As long as your lowest velocity meets PF, don't worry.

[sargenv]

Something I didn't see mention here is to buy several different reloading manuals and read them. Most of the answers to your questions will be in those books. I have several Speer manuals, a couple Hodgdon manuals, an Accurate Arms manual, and several of the manuals put out by powder manufacturers. I also have several shotshell reloading manuals since I also reload for shotshells. I've seen a lot of questions here that are all pretty much answered by reading the manuals. I would reccomend this to any new reloader in addition to reading the information stated here on the forums.

Vince

[Patrick Sweeney]

Just to stick an oar in here, there are only two times I bother with single-brand brass: my ICORE revolver moon clips only work with Remingotn brass. And I have a couple of cubic feet of .38 Super brass for Major Open.

Everything else gets loaded in whatever brass falls out of the tumbler clean.

ES (extreme spread) of 60-88 is on the high end, but not unusual. I just did a bunch of 9mm chrono work, and I had a few loads up there. As long as your ammo will average around 132PF, and makes Minor per the USPSA method, a large ES is not a problem.

Rikarin, I'm more worried about your reported pressure signs. The threshold for Minor in a 9mm is so under the book max, that you should never be seeing pressure signs with competition ammo.

I've loaded buckets of 9mm with Titegroup, a fast powder, and with a 147 grain bullet I can make Minor (depending on the gun) with 2.8 to 3.2 grains. And no pressure signs.

[Flexmoney]

I am going to go along with Patrick and gm iprod and suggest that you switch to TiteGroup. It will be a lot safer.

(And, if you are getting flattened primers, then you are already unsafe...no matter if you are a new reloader or have been at it for years.)

I know you want the softest shooting load. You won't be giving up much (if anything) by going with TiteGroup. it is still pretty fast...so watch it for signs of pressure too.

[Rikarin]

Thanks so much for your concern, you guys are so sweet and caring... my hand would be appreciative.

Hehe. I already made bit hot ammo and two double charges and I know what happens to be unsafe. It went BOMB and blew magazine catch off. (yes, I took apart everything and check everything for cracks and stuff too)

So I have to say Powder Check System is god's send to me! It rocks! Oh, and case lube! It used to be two armed job to push that handle down and up, now like 2 finger job. I can save my wrist for actual shooting.

The load I made was too hot, chrono-ing 950FPS and such, what a waste of powder. I actually decreased by 0.2gr now for VV310 and started load with VV320 to see how it goes. I talked with Matt's really good student and we basically load same. I really can not find the burning rate of TitGroup compare to VV310 (I have most of the powder's burning rate. VV320 is between Clay and Royal Scot, VV310 is btween R-1 NOrma and Blueseye Is Titgroup faster than HP-38??)

My rigional IDPA is on 7th and I really need to nail down on the load so that I can actually practice with what I will use at the match.

I also was talking with Brian today and when I told him about my double load he cracked me up by saying so calm and so matter of factly ".....yeah, that happed all the time when we used to experiement"

I am going to go along with Patrick and gm iprod and suggest that you switch to TiteGroup.  It will be a lot safer. 

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[Rikarin]

VinceThanks, Thats I thought. I am so lazy. Too many to read/learn (including learning to use my brand new 650) I am relying on quick answers from knowldgeble people. I will buy one.

[Stumpnav]

If you want an eye opening experience, weigh different brand cases and compare the weights. Since all the cases have the same deminsion on the outside, the weight difference you see is a reflection of the internal case capacity. A different internal capacity gives the same effect as seating bullets to different lengths. The pressure generated by the exact same amount of powder will result in a big ES for velocity.

The Sierra books are really good and they have the 1-800 number you can call and talk to somebody "in the know".

[Lee Watne]

I have found that the most consistent velocity loads are with new brass of the same lot and manufacturer. Try some new cases with the same load and see what you get.

[Gun Geek]

If you want an eye opening experience, weigh different brand cases and compare the weights. Since all the cases have the same deminsion on the outside, the weight difference you see is a reflection of the internal case capacity. A different internal capacity gives the same effect as seating bullets to different lengths. The pressure generated by the exact same amount of powder will result in a big ES for velocity.

The Sierra books are really good and they have the 1-800 number you can call and talk to somebody "in the know".

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Even worse than that, get a bunch of different brass and fill them up with something (water, powder, sand). Pour out the material and weigh it. This is a direct measure of case capacity and it will startle you - 20% maybe!

On the SD/ES thing, my chrono (a CED) calculates ES, SD and a 95% interval (+/- based on a normal distribution, I think). Below are a couple of 5 rd strings. I usually do longer ones, but these were handy...

GROUP #9

1) 836.2 -22.8

2) 873.8 14.8

3) 851 -8

4) 859.4 0.4

5) 875 16

High: 875

Low: 836.2

E.S.: 38.8

Ave.: 859

S.D.: 16.2

95%: ±20.0

GROUP #10

1) 875 14

2) 862.2 1.2

3) 848 -13

4) 862.2 1.2

5) 858.4 -2.6

High: 875

Low: 848

E.S.: 27

Ave.: 861

S.D.: 9.6

95%: ±12.0

[Patrick Sweeney]

Rikarin,

Titegroup is right in between AA#2 and VV-320. VV-310 is the fastest powder available. The question about mixed vs. same-headstamp brass isn't "does the capacity differ" but "Is there a difference in accuracy or velocity?"

I've loaded enough very-accurate ammo in mixed brass to come to the conclusion that for all but the most exacting uses, there is no difference.

Were I in the position of trying to elbow Dave Sevigny out of first place, I'd be doing it with new, identical brass. Since that isn't going to happen any time soon, I refuse to waste time sorting by headstamp.

[DogmaDog]

No one has mentioned a couple of things yet:

Have you looked at your bullets, and weighed them? My 175 gr .40 bullets vary from about 170 to 176 grains, and average 174.5. Naturally, the heavier bullets will go slower with the same powder charge. If the bullets you shoot have a large variance in mass, that would contribute to your "problem".

How's your loading method? Often, researchers will get inconsistent results the first few times they try an experiment, because they haven't developed a consistent technique yet. Once they do it a hundred times, the results become more consistent. If you're loading very small batches, you might be seeing larger deviations than you would if you sat and loaded 500 at a sitting. Using case lube may help with this--if you're having to use a lot of force on the handle, that can rattle the machine and cause inconsistent powder drops.

Verify that your loaded rounds all have the same OAL, and crimp dimensions. Inconsistent or loose crimp, especially, could cause erratic performance.

Anyway, I don't sort my cases by headstamp or number of firings. I pick up whatever .40 is lying on the range after a match, unless it's bent, split, or really dingy. I load with WST powder, and get extreme spreads of about 40 fps, and standard deviations of about 10 fps from sample sizes of 10 shots over the chrono. So ES of 60 to 80 isn't insanely large (if you're shooting more bullets over the chrono, then it might not be a greater variation than I see in my loads).

All you want from the chrony is to ensure your loads will make power factor. Test for accuracy by shooting groups. Your loads may be accurate despite a large-ish variation in velocity.

I bet your problems will disappear as you get some more experience reloading.

Goo luck,

DogmaDog

[Rikarin]

Herm, oh, no wonder people say which bullet is good! I thought all bullets are made equal. I am using Zero, because it was relaly cheap and best yet, even 9mm 147, it is very rounded top. Flat toppy one got stuck on the ramp of chamber. I changed that plastic part of magazine, experimented with OAL but Zero just gave me no problem at all.

I will weight today.

thanks others for capacty/weight of the brass. Recoil management is one of the most challenging thing for me and I shoot so much better when the PF is low. So, I want to make absolute minimum PF load.

Have you looked at your bullets, and weighed them?  My 175 gr .40 bullets vary from about 170 to 176 grains, and average 174.5.  Naturally, the heavier bullets will go slower with the same powder charge.  If the bullets you shoot have a large variance in mass, that would contribute to your "problem".

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[Patrick Sweeney]

A chrono is second only to a Dillon in importance for loading. I found that the BHP project gun ("Prime") is very fast, and I can make Minor with a 147 Durocast and 2.8 of Titegroup, where other guns require as much as 3.2.

In the BHP, 3.2 delivers a 138-139 PF.

You must weigh bullets, and measure velocity in your own gun, to be certain of what is actually happening.

[Rikarin]

Oi, this convinced me. Thanks for the info! I will experiment after the match.

Titegroup is right in between AA#2 and VV-320. VV-310 is the fastest powder available. 

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