Author Topic: First Post - Help with chrono results  (Read 4304 times)

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Offline ptouchton

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First Post - Help with chrono results
« on: February 11, 2017, 10:25:44 PM »
   First off I want to say thank you for all the great info on this site. I have been lurking out here for months gleaning as much information as I could in this reloading quest. I have read all the stickies and book marked so much great information. Thank you.
   Now for my delima, I chronoed a load ladder today and the results have me baffled. I have been able to understand every step in the process of working up a load until today. I am hoping someone can see the error of my ways and get me back from the brink of insanity.

Pistol: P09 9mm
Push test with berrys 124gr hbrn-tp: 1.189-1.190
powder: win 231
primer: winchester spp
OAL: 1.140 ( checked each length with digital caliper)
Hodgen data: Winchester   231   .356" 1.150" 3.9   920   27,400 PSI      4.4   1,037   31,900 PSI

ladder: 3.9,4.0,4.1,4.2,4.3 (I used the formula for shortening oal and the numbers stayed the same -- did I go wrong here?). I built the ladder hand weighing every charge using a dillon beam scale that had been checked using weights.

chrono results (pro chrono digital):

gr     avg fps  ES     SD    +
3.9    971       47     19        - a little higher than i would have thought
4.0    1004     50     18    7   - decent increase es seems high but I continue
4.1    1046     26     10    42  -
what the heck!!...In my defense I was only watching the numbers on the extra shot I built for my strings. I wanted one that I looked at the velocity on the chrono to be sure I was okay. Then I concentrated on shooting through at the same point over the chrono everytime. The first shot at 4.1 came in at 1020....seemed like that was fine. It wasn't until I went up to review that I saw the rest of the string up in the 1040-1050s.
     I stopped at 4.1 since I had exceeded the 1037. I really didn't expect that, this ladder leaves me nowhere else to go. Am I reading this correctly? and what are your thoughts on where I fumbled.

Thank you

Offline 1SOW

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Re: First Post - Help with chrono results
« Reply #1 on: February 12, 2017, 12:17:44 AM »
What specific bullet description did Winchester show with Winchester's load data test results?

Your results sound faster than mine did.  I use the Pro Chrono and the BRY 124 hbrn but not with 231
  I have used 231 and needed more powder to make those speeds with a 124 RN bullet,  so I'm a little puzzled too.   :(

Offline IDescribe

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Re: First Post - Help with chrono results
« Reply #2 on: February 12, 2017, 01:38:40 AM »
At the powder drop:

Are you using a typical powder drop?  If so, it's fine to weigh a bunch of individual charges to make sure you're not getting wild charge weight swings from one drop to the next, but just do ten individual charges once to check.  To set your powder drop, weigh ten drops combined and divide by ten for your single charge weight. This gives you a little more precision on average drop weight.  If you think your consecutive drops are 4.0 and 4.1, but they're actually an average of 3.97 and 4.13, that 1.6gr increase (average) is going to produce more velocity than expected when you think it's a .1gr increase.

Also, use check weights to adjust the beam scale again.


Tips to tighten up your chrono readings:

What were your chrono conditions?  I am in sunny Florida, and the chrono works a lot better at 9:00AM with partly cloudy skies than it does at 1:00PM on a clear day. 

I set up a target stand between the chrono and the sun, so that the target stand casts a shadow across both sensors.

Get your chrono sufficiently far from your pistol.  Don't worry -- you're not going to hit it.  Probably. ;)

The shinier the bullet, the less consistent the chrono readings.  Plated bullets are the shiniest and give the worst readings.  Take a Sharpie and mark up the noses. 


Also, regarding your results, there is a charge weight at which you will start getting a fast pressure seal.  At this point, you usually see a bigger than average velocity jump because the chamber isn't losing any gas or powder that slips out between the case walls and chamber walls before the pressure seal is created.  That could be a contributing factor.

Seriously, check your scale again.  The biggest safety consideration here is that you're using more powder than you think you are.  4.1gr of W231 with a 124gr Berry's RN at 1.14 doesn't worry me at all.   Also, keep in mind that even if your chrono is telling you right, going up to 4.3gr is going to put you into +P, but it's not going to blow up the gun.  I'm not saying you want to make it your go-to load and run it thousands of it through your pistol, but 10 rounds isn't going to kill the gun.  I've shot 4.6gr with a jacketed RN over-sized at .356. 

I'll also tell you that as pressure keeps increasing past the point of the good pressure seal, you start getting diminishing returns on your powder.  As you go up a ladder, you might see

3.9 -- 1000 ft/s
4.0 -- 1020 ft/s
4.1 -- 1040 ft/s
4.2 -- 1060 ft/s
4.3 -- 1070 ft/s
4.4 -- 1075 ft/s

If you see that, where the incremental increase in velocity starts dropping off as you keep going up in powder charge, THAT is when you need to stop dead in your tracks.  If I get a 42 ft/s increase in velocity from a single tenth increase in powder, my response is "Whoo hoo!  Plenty of head room left to go!"  ;) 


Recheck your scale. Recheck your scale. Recheck your scale.   Make bleeped sure your drop is dropping what you think it is.  Then make up a full ladder again and retest.  And weigh ten drops at a time to get a more precise average.   Color your bullet tips with a Sharpie.   Then chrono between 9:00 and 10:00 in the morning.  ;) 
« Last Edit: February 12, 2017, 10:15:43 AM by IDescribe »

Offline ptouchton

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Re: First Post - Help with chrono results
« Reply #3 on: February 12, 2017, 09:52:06 AM »
Thanks for the quick responses!

1sow - The bullet description in the test data was berb 124gr hbrn-tp. For my first ever reloading experience I tried to use every component that was in the test data.

IDescribe - For my powder drop I am using the Dillon 650xl. I really thought I had ruled out any variable by running this thing in a single stage manner. Also, for the drops I was leaving them short say 3.7gr...putting that in the scale...then using a lee dipper to manually bring the charges up.
    I will double check the scale again. The process I used before was to check using
        1. 20 grams
        2. 4 grams
        3. 2 grams
        4. 20 mg.
I do have to crank that wheel to get it to zero and I was wondering if my work bench "out of level" could be a problem?

My chrono conditions: I'm in Portland, Oregon....and yesterday was the first non-cloudy day on awhile... :)....I did get out there about 9:00 and setup the chrono in the shade but, I'll be honest I didn't pay attention to any sun factor Heck I didn't know that could be a thing till I got back from the range and read a few threads. The Chrono box said " just turn it on and shoot".... :D. I did eventually find your post about shading the chrono I will definitely do those things the next time out. I set it up about 10ft. away and from a standing position I shot through the chrono. I decided the setup would be easier since my range is an open bay type and trying to drag a table and chair would be too much.

Also, I keep forgetting to mention I am trying to bring this load to minor PF.
« Last Edit: February 12, 2017, 10:03:32 AM by ptouchton »

Offline rodolfo

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Re: First Post - Help with chrono results
« Reply #4 on: February 12, 2017, 10:51:45 AM »
I load 4.2 gr of Win 231 with 124 gr FMJ.  The bullets have the jacket covering all of it except the base, which is more or less flat.  They are from Precision Delta.  It has been a few years since I chronographed  them but, they averaged 1020 out of my SP-01.  This is the load that I shoot most of the time.  It is a nice load, a hundred fps lower than factory that is easy on my arthritic hands. 
CZ-83 380ACP
CZ-75 c 9mm
CZ-97 BD 45ACP
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Offline IDescribe

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Re: First Post - Help with chrono results
« Reply #5 on: February 12, 2017, 10:56:45 AM »
For my powder drop I am using the Dillon 650xl. I really thought I had ruled out any variable by running this thing in a single stage manner.

Using a machine in a fashion other than what it was designed is more likely to introduce variables than eliminate them.  I assume that by "running this thing as a single stage" you mean you insert a case, then don't insert another case until the current case has hit all five stages and come out complete.  You can continue to do this, I guess?  But you need to take out those extra steps you've added where you pull the case and measure powder.  And you need to get to using the press as designed as quickly as possible.   And when you start using it as designed, you may need to readjust some dies.  The shellplate rocks and flexes differently when it's full than when it has once case in it.  Make sure you check.



Also, for the drops I was leaving them short say 3.7gr...putting that in the scale...then using a lee dipper to manually bring the charges up.

I hope you mean trickler and not dipper.  Either way, stop doing this.  If you had a scale of greater precision, and you were shooting at 600 yards or more, I'd say to keep going, but for a scale that measures to .1gr, and that you have to eyeball, I doubt you're accomplishing much, and you might be accomplishing the opposite of what you're trying to.  I don't know.  Set your drop for what charge you want, and go with it. 



I do have to crank that wheel to get it to zero and I was wondering if my work bench "out of level" could be a problem?

Is your reloading press attached to this work bench?  If so, your scale needs to be elsewhere.  Never use your scale on the bench your press is attached to.

Also, zero and check your scale at the beginning of every session.  But if it's zeroed, and it weighs your check weights accurately, then whatever it's sitting on is level enough.  Just don't put it on something that you're going to shift around -- while operating your press or otherwise.


My chrono conditions: I'm in Portland, Oregon....

I've operated my ProChrono Digital only in central Florida.  So everything I say is tied to that.  I can tell you that overcast days are better than clear days.  And I can tell you that the sun low in the sky is better than the sun high in the sky.  I can tell you that the duller the bullet, the smaller the standard deviations will be.  I can tell you that at the opposite end of the spectrum, I've managed to get some super shiny plated bullets at the right time of day to clock FAR faster than what they were actually going.

You are in Oregon.  Your mileage can, might, should, and probably will vary.  ;)

In related news, I visited Portland back in September, and Deschutes is now easily my favorite pub on the planet.  If I lived there, I would have a problem.  ;)
« Last Edit: February 13, 2017, 12:04:15 AM by IDescribe »

Offline ptouchton

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Re: First Post - Help with chrono results
« Reply #6 on: February 12, 2017, 12:56:15 PM »
I will definitely move the scale off the bench. I realize now it needs to be on a more undisturbed surface. And I think more at eye level to check the zero.

I do think I was a little to vague when I said single stage...Here was my process that i thought was little more precise than just setting and throwing charge for the whole string.

1. Size and prime 6-8 cases and set aside.
2. using a case throw 3.7 grains of powder and dump into the pan.
3. using the lee dipper drip grains into the pan until it got to the desired weight.
4. Then pour the pan into one of the primed cases.
5. Then seat the bullet to the 1.140 oal checked with the calipers.

I have also removed all crimping from the FCD because I wasn't belling the cases based on a suggestion that the berrys seats without it stripping the plating. so, my final size is .378 on the crimp.

I will try all of the suggestions you have given and hope it gets better.

This hobby is fun/tedious and frustrating all in one and so far I really enjoy the process...I think.... :D

Offline muncie21

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Re: First Post - Help with chrono results
« Reply #7 on: February 12, 2017, 03:52:32 PM »
Hi OP,

I agree with some of the folks before me, that you could have a powder measurement issue.  Have you tried setting the powder drop to your target weight by measuring 10 drops and dividing by 10, as ID mentioned?  I do this with the missing case rod disconnected, so I can manually activate the powder throw mechanism.

Once you have the 10 throw measurement set, measure a few (I normally pull 2 cases at a time from stations 3&4, and do this 3-4 times) cases one the shell plate has cases in each station.  Depending upon the powder you're using you may need to tap/shake the powder tube/reservoir a few times to prior to measurement, to get the powder to settle.

Offline Wobbly

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Re: First Post - Help with chrono results
« Reply #8 on: February 12, 2017, 09:29:24 PM »
You're getting all great information.

I agree. You have a chrono setup issue. Your chrono may be too close to the gun, so you may be reading some of the muzzle blast. 10 feet minimum separation. Cloudy or overcast days are best; bright with no direct sunlight.

My Dillon powder measure is dead nuts on with W231. It's one of the best metering powders out there. But have you metered out at least 10 "drops" of powder before you start to take weight measurements ? The powder has to work itself to a consistent density. I like how you drop short and meter the balance in, but that's unnecessary.

Also start using a single brand of brass. The difference in case volume between brands will throw you off.

My older Hornady book shows a load range of 3.9 to 5.2gr at 1.040" topping out at 1100 fps. The top is somewhere between 1070 and 1100 for sure.

All the best.  ;)
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Offline Dan_69GTX

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Re: First Post - Help with chrono results
« Reply #9 on: February 13, 2017, 12:58:35 PM »
Also start using a single brand of brass. The difference in case volume between brands will throw you off.

That happened to me!!

For shade I'll use an EZ-up pop-up tent to cover the chrono instead of me.

For a portable table by the press that can adjust height - I use a "keyboard stand" and place a piece of wood on it that clamps to the cross bars.  Works great!  You can find keyboard stands at yard sales for around $5.

I place my scale and books/notebook/etc on it.

Here is a link to one.  No, I didn't get mine here, it is just so you can see what I'm talking about.
https://www.sweetwater.com/store/detail/XStdXLt?adpos=1o2&creative=55644138841&device=c&matchtype=&network=g&product_id=XStdXLt&gclid=COiYysHSjdICFY2LswodnswABQ

Clips I used:
https://www.google.com/search?q=broom+clamp&tbm=isch&imgil=XasJ084-NWiuLM%253A%253BWyoeE1QdKhM6NM%253Bhttp%25253A%25252F%25252Fwww.miketrask.com%25252F5a649b-broom-clamp-quick-shopping&source=iu&pf=m&fir=XasJ084-NWiuLM%253A%252CWyoeE1QdKhM6NM%252C_&usg=__fT_Im4ZMg4j-l1r70MJH4uNwH8Y%3D&biw=1344&bih=701&ved=0ahUKEwjJrZnY0o3SAhVI4WMKHSnZANUQyjcItwE&ei=UvOhWMm8AcjCjwOpsoOoDQ#imgrc=XasJ084-NWiuLM:

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Offline IDescribe

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Re: First Post - Help with chrono results
« Reply #10 on: February 13, 2017, 01:07:06 PM »
I have a buddy who uses a pop-up tent like that.  Seems to work well for him.

Offline jimny

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Re: First Post - Help with chrono results
« Reply #11 on: February 13, 2017, 02:53:58 PM »
I am loading 4.2 grains of Win 231 with an Extreme 124 gr RN plated bullet at 1.140". Loaded on a Hornady Lock n Load progressive ammo plant. My Pro Chrono is set up at 12' from the firing line. I consistently get velocity of 1050 fps with an sd of 9 or 10. And here in upstate NY the cloudy days outnumber the sunny days, for consistent chrono results.

Offline ptouchton

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Re: First Post - Help with chrono results
« Reply #12 on: February 13, 2017, 08:32:00 PM »
Thank you for all of the replies....I am going to be using all of the suggestions for the next round this Saturday....

I'm still trying to grasp the 10 drop divide by ten routine. Does this mean drop all ten in a single pan...weigh that and divide by ten. And if that number comes out to the desired weight then I'm good to run?

1. move scale off of the bench
2. ditch the mad scientist routine of manually bringing charges up to weight.
3. set and shade the chrono 12-15 ft early in the am.
4. take a black marker and color the shine off of the bullets.

I like the portable stand idea...my garage is already full of woodworking equipment and I just don't have any more room for another permanent table.

Thank you guys for helping me try and dial in this process!

Offline IDescribe

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Re: First Post - Help with chrono results
« Reply #13 on: February 13, 2017, 10:04:06 PM »
If I want to shoot groups, I shoot off a bench.  If I don't care about shooting groups at the same time, I'd rather shoot standing, off hand.

Measuring drops individually, like once ever with a particular powder, just to make sure your drop isn't throwing wildly different charges from one drop to the next -- that's fine.  But when you want to set your powder drop, drop ten charges, put them into the powder pan, and weigh the ten charges together.  So if you're going for 4.2gr, you keep adjusting to where ten-drop sum equals 42.0 grains -- and 42 / 10 = 4.20gr.

NOW, once you get it to 42.0gr, or close to, you should probably run 10-drop charges a couple of times and weigh them so that you can see what kind of shift you're getting.  You might get 42.0gr for one 10-drop charge, then get 42.2 the next time, then get 41.9 the next time.  You're going to get some drift.  And it's good to know which powders drift a little and which ones drift a lot. I am NOT saying you do this at every charge weight.  I'm saying you do this a few times with a powder to see how that powder operates in your powder drop.

I would also suggest that it's not super important to get 42.0 exactly either when you're going for 4.2gr.   Once you know that it drifts a little, then you know that even IF you get 42.0gr on the nose when you measure, it's not likely the next ten drops that go into your cartridges would add up to exactly 42.0gr anyway, so don't kill yourself trying to get it on the nose.  I am happy if I come in within three tenths for the 10-drop total.  If I want 4.2gr charges, and I adjust the drop and get a 10-drop sum of 41.8, that's close enough for me.  In my records, I record those drops as 4.18, just so I know, but I'm not going to fiddle with it looking for exactly 42.0gr if the next ten aren't likely to be that anyway.  It's worth noting to the hundredth in your records, though, because it can explain anomalous jumps in a ladder.

I believe Wobbly is suggesting that you run cases through and drop the charges into the pan.  That way, the case will run the drop while setting it to a charge weight exactly as it will be run during manufacturing.  That's quality control.  I don't personally do that.  I hold a cordial/liqueur glass under the drop and cycle it ten times by hand.  BUT I tested it with cases first, and compared that to ten manual indexes of the drop, and there's no difference greater than the normal drift I get anyway, and it's faster to do ten at a time manually.  That's with my drop, though.  Don't assume it's the same for yours. 

Offline Wobbly

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Re: First Post - Help with chrono results
« Reply #14 on: February 14, 2017, 06:40:39 PM »
I believe Wobbly is suggesting that you run cases through and drop the charges into the pan.  That way, the case will run the drop while setting it to a charge weight exactly as it will be run during manufacturing.  That's quality control.  I don't personally do that.  I hold a cordial/liqueur glass under the drop and cycle it ten times by hand.  BUT I tested it with cases first, and compared that to ten manual indexes of the drop, and there's no difference greater than the normal drift I get anyway, and it's faster to do ten at a time manually.  That's with my drop, though.  Don't assume it's the same for yours.
 

Not exactly.

? I always dump powder on a Dillon into a cartridge case. I never manipulate the PM by hand. The shaking of the PM on the "return" stroke is the vibration that shakes the powder in the hopper to a consistent density. This is extremely important !! So I want that action occurring just as it would during production.

? Then I discard the first 10 drops to let the action of the PM achieve that consistent density; back into the hopper they go. I can be making single-drop [coarse] adjustments during this time, but I never use one of those drops for production.

? Then I do the summing of the 10 drops to achieve the final [production] setting.

I use the press-on blue knobs you can get off Ebay on all my PMs so I can get very fine adjustments. If you don't have those, you might want to look into getting some.



 ;)
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