Scales and Calipers? You get what you pay for.

[Point&Shoot]

I use what I think are the cheapest scales and calipers known to man. If i set-up the 550B to seat and crimp the bullets at say 1.125 I find my length varies from 1.123 up to 1.127. Do you think it's because of the cheap calipers or the Dillon. I don't think it's the 550B so what's left.
The same goes for my cheap scale. If I set up the powder drop so I'm getting say 4.6 grains per drop sometimes it will creep up to 4.7 or even down to 4.5. Sometimes the weight doesnt move at all. It doesn't happen as soon as the powder hits the pan and the fluctuation takes a minute or two.
Am I just getting what I paid for and will better scales and calipers make a difference. Thanks a lot folks and I'm ok with buying what I need but the length and powder weights vary just enough to bum me out but not affect hangun accuracy all that much. Traditionally the Dillon meters a fine powder drop so whats going in??

 

[Fixxah]

Which are you talking about? I bought my calipers at grainger. I have a Hornady as well as an rcbs that are accurate.
Try setting up the scale in a different location. I remember something similar from years ago but forget who posted it.

 

[Tallen]

I started with Franklin Arsenal calipers which started throwing erroneous measurements after 3 years. Replaced with Mitutoyo calipers and haven't looked back.

For the scales - consider verifying your digital readings with a beam scale to determine if the scale is the culprit.

 

[milktree]

You could get be getting inconsistent OAL lengths because of inconsistent bullets. If the seating die doesn't press on the very tip of the bullet, any variation in ogive will give you a different OAL.

Have you measured any consistent weight against itself over time? e.g. take a bullet, weigh it. Then weigh it 20 minutes later. Does it change?

It's entirely possible for a 550 to run an inconsistent charge with some powders.

 

[cockpitbob]

What milktree said about inconsistent bullets. Usually the seating die presses down from the tip on the ogive.

 

[EddieCoyle]

I’d be pretty happy with +/- .1 grain variations on a powder drop with a Dillon powder measure.

 

[allen-1]

I'm with Eddie on this but with regards to the OAL. You're talking +/- two one-thousandths of an inch on a mechanical press. If you were talking hundredths of an inch I'd be concerned, but not for thousandths.

 

[mac1911]

Looks like your well with in the +/- accuracy of your equipment.
For what its worth I just bought the Lyman gen6 scale.
I can't say its any more accurate than my other scales but it does not fluctuate if left to sit there like my hornady or digi weigh.
As for your bullet COAL I'm surprised you get that good result with the variance in the bullets being part of the problem also.
Measure a few bullet oal then maybe measure ogive length see what you come up with

 

[xtry51]

Stop using digital calipers

A few thousandths variance on OAL is normal. Not every bullet or pc of brass is the same.

+/-.1gr drops is just fine for powder. Even on pistol round loads .1gr is not a high percentage of the overall load.

 

[peterk123]

What others have said above about variances in bullets, brass, movement of shellplates, etc. My 9mm reloads range from 1.110 to 1.118. I am no where near max loads, so I don't care. One of my guns has a match barrel and is very picky about OAL and my conical bullets (ogive hits the throat). As long as I am below 1.120 I am good; and it is all that matters.

Even measuring diameter will give different readings if you are using mixed brass because not all brass walls are the same.

Pete

 

[RImike]

I have a set of cheapo Harbor Freight Calipers, why, because I drop shit all the time. They don't have to be accurate but they have to be consistent. I have a known standard that I calibrate off of every time. The HF calipers are always dead nuts on. My guess is that it it's the bullets that are throwing things off for you, not the measuring device. Have you measured them before seating to ensure they are all consistent? If you were going for precision rifle rounds that is one thing, if it's pistol rounds it doesn't really matter.

 

[Point&Shoot]

Well I'm using a cheap Frankford scale and calipers but I'm willing to spend more as long as everything is more consistent. Right now I'm using Xtreme 115gr RN with W231 powder and CCI primers. The one variable there is that I'm using mixed brass. Maybe it is the brass. It's mainly once fired brass taken out of the barrel at the range.
I came up with 1.125 because I have six 9mm handguns and they all run fine at that COL. Cheap Federal ammo comes in at 1.149 to 1.152 which is more consistent than the cheap Remington which is 1.111 to 1.114 The length of the Xtreme bullets is .551,552,.553 but no dramatic differences. I have weighed the Xtremes and they range from 114.6 to 115.6 which I don't think makes much difference in 9mm. The Xtremes sit nicely on the bell on the press and seem to go straight into the die and I'm using a very light crimp. I guess I should weigh up a few bullets and see if that changes over time.
Am I making a mountain out of a molehill? Function is good in all my 9mm's and offhand accuracy is as good as it gets for me. Is the Dillon known for throwing inconsistent powder drops? I like the W231 (I thought) because a double charge fills the case and is easy to see. I have plenty of powders to chose from but is there any point for my applications. Will Titegroup, WST, Autocomp, Bullseye, Clays etcetera meter any better. I don't have a triple beam but I can check out powder weights and on a Pal O Mines scale and calipers. We will see. I hate to change it up to much right now cause I've got a lot of Xtremes, W231, and CCI primers but I really am trying to find good recipes for a handful of different powder and components so maybe ill just make a 1000 more of these and move on to another powder. Thanks for the input guys. I hope I covered eeverything but if not please let me know.

 

[peterk123]

I am using BE-86 (I think it is like Power Pistol but with a flash suppressant) for 9mm and 357 mag. It meters really well and has a huge range for 9mm. I have gone as low as 4.3 grains and I believe some have loaded to 5.9 grains, maybe even higher. I have settled on 4.6 grains. I use a Hornady Progressive. I used to use a Lee Turret and sometimes the drums caused issues and it would not meter well. Make sure you get rid of all static (dryer sheets), and get some graphite powder and run it through your powder charge. I found that the graphite does wonders and I use it in my Hornady as well. Hope this helps. Be safe. Pete