In Praise Of Gravity/Beam Scales

[Mark W]

I posted this thread a while back about my experience when I loaded some .243 ammo with a @sparker tuned scale and then later checked some of them with an FX 120i. If I could only keep one scale it would be the tuned beam scale.

Scale Consistency

About 2 1/2 years ago I worked up a good shooting load for my CZ 550 chambered in .243 and loaded 50 extra rounds. Sometime after this I lost a lot of my load data when my basement flooded. I knew the load consisted of Sierra 85 Gr HPBT over IMR 4064, but I didn’t know the charge weight...

forum.accurateshooter.com

 

[natdscott]

Gravity does not D R I F T.

That's actually not correct.

 

[Bc'z]

That's actually not correct.

Explain

 

[rwj]

That's actually not correct.

Doubtful it will vary over the beam’s length…

 

[Dgd6mm]

I've got to read this explanation..

 

[Kyle Schultz]

1. In a recent match of four strings of 20 shots at 800 yards, my average velocities for the four strings were 1389, 1387, 1390 and 1389. SD was right around 8 FPS per Shot Marker values at the target.
2. Those who are mathematically inclined, have already surmised that the SD for the averages of the four strings is smaller than the SD for any 20 shot string.
3. How can this be? First, a load that produces consistently uniform velocities and pressures through the temperature variations. Second, the absence of drift. The scale reads the same regardless of time of day or temperature swings.
4. While many may tout the low deviation values of this load or that load, it is rare to see the level of ballistic uniformity that I experienced.
5. I use a tuned beam scale. I always know exactly how many kernels of powder are in a case.
6. You should too!

Would love to give the beam scales another try but that's hard to do since you've had my Lyman M5 since Oct 30, 2021. I don't care anymore if you tune it or not but would appreciate you sending it back to me.

9-3-2022 Update

Received my scale back from Scott.

 

[natdscott]

Explain

Oh, I'm just being a pedantic jerk, but in good fun, for sure.

That said, what we currently define as "Earth's gravity" does indeed vary quite a lot in magnitude over time, and by location at any given moment. The easiest to explain is elevation. Higher ya go, the lower gravity is (as a general statement). If you weigh a sample to be 100.00xx grams in Denver, CO, it can be show to be OVER 100.00xx grams in someplace like Death Valley.

The magnetic poles are in continuous movement, and require us to constantly re-orient hard copy maps and I'm sure geo-oriented software and aerial hardware as well.

Earth's magnetic field also completely changes polarity in what seem to be fairly "random" intervals from 8,000 years to tens of millions, at times. Very easily seen in oceanic basalt records, if you know how to look, and do a little math.

And before anybody asks, no, geology is not contrary to the "God narrative", unless somebody chooses to make it so.

Doubtful it will vary over the beam’s length…

Not in a way measurable by us.


Have a nice night, y'all!

 

[jelenko]

Explain

Nate is just being controversial.

Because the core is molten and the mantle is semi molten, the force of gravity can change with time at any specific point on the earth's surface.

You'd need some real highly, highly sensitive equipment to see it.

ETA. I see Nate beat me to the punch.

 

[sdean]

Would love to give the beam scales another try but that's hard to do since you've had my Lyman M5 since Oct 30, 2021. I don't care anymore if you tune it or not but would appreciate you sending it back to me.

My FX 120 worked the day I got it. Didn't have to wait a year or two to get it tuned.

 

[1bamashooter]

Would love to give the beam scales another try but that's hard to do since you've had my Lyman M5 since Oct 30, 2021. I don't care anymore if you tune it or not but would appreciate you sending it back to me.

That's pathetic

 

[JFrank]

1. In a recent match of four strings of 20 shots at 800 yards, my average velocities for the four strings were 1389, 1387, 1390 and 1389. SD was right around 8 FPS per Shot Marker values at the target.
2. Those who are mathematically inclined, have already surmised that the SD for the averages of the four strings is smaller than the SD for any 20 shot string.
3. How can this be? First, a load that produces consistently uniform velocities and pressures through the temperature variations. Second, the absence of drift. The scale reads the same regardless of time of day or temperature swings.
4. While many may tout the low deviation values of this load or that load, it is rare to see the level of ballistic uniformity that I experienced.
5. I use a tuned beam scale. I always know exactly how many kernels of powder are in a case.
6. You should too!

I’m still culling out cases that display extreme FPS variances but this is what I got the last time I used a chronograph.
Ohaus 10-10

 

[SeabeeKen]

Oh, I'm just being a pedantic jerk, but in good fun, for sure.

That said, what we currently define as "Earth's gravity" does indeed vary quite a lot in magnitude over time, and by location at any given moment. The easiest to explain is elevation. Higher ya go, the lower gravity is (as a general statement). If you weigh a sample to be 100.00xx grams in Denver, CO, it can be show to be OVER 100.00xx grams in someplace like Death Valley.

The magnetic poles are in continuous movement, and require us to constantly re-orient hard copy maps and I'm sure geo-oriented software and aerial hardware as well.

Earth's magnetic field also completely changes polarity in what seem to be fairly "random" intervals from 8,000 years to tens of millions, at times. Very easily seen in oceanic basalt records, if you know how to look, and do a little math.

And before anybody asks, no, geology is not contrary to the "God narrative", unless somebody chooses to make it so.


Not in a way measurable by us.


Have a nice night, y'all!

So my max load in 284 W loaded @ 3000' will be overpressure at sea level?

 

[Rocketvapor]

That why they make check weights.
A digital scale sold and calibrated in Canada will need to be recalibrated with an "Apparent Mass" in Florida because of a change in Latitude (and altitude). A single calibration point takes care of Gravity calibration. Beam scales carry their own "Apparent Mass".

 

[natdscott]

So my max load in 284 W loaded @ 3000' will be overpressure at sea level?

Maybe, but not because of gravitational differences.

Did you miss the "...pedantic..." part?

 

[Rocketvapor]

Digital scale gravity error (due to difference in local gravity) probably won't impact those weighing charges to 1/10 grain. 39.9 to 40.1 grain is +/- 0.25%.
The gravity error between Dallas and Boston is about 0.1%, Anchorage and Dallas about 0.25%.
Elevation, Denver for example has an elevation delta of about 0.05%.

Calibrate your digital scale at your location and all be good.

Would a beam scale read correct on the moon? Why?

 

[DLT]

Would love to give the beam scales another try but that's hard to do since you've had my Lyman M5 since Oct 30, 2021. I don't care anymore if you tune it or not but would appreciate you sending it back to me.

9-3-2022 Update

Received my scale back from Scott.

This is among the many reasons I chose not to send my scales.

 

[sparker]

This is among the many reasons I chose not to send my scales.

DLT, I get it, truly I do. Many people have waited for far too long. I do not blame you for not sending your scales to me. In fact, I had no idea you were contemplating it. But now that I know, I can work on living with the sorrow of having the knowledge that you were perhaps contemplating having me work on your scales but decided against it.

That said. I’m at a place now where I can tell a customer when to ship a scale to me and get it turned around in a week. So, DLT, should you decide to risk it all and inquire about potentially getting one or another of your scales tuned and calibrated, I assure you I will have it for the absolute minimum time possible.

All the best!

Scott

 

[cmysix]

Explain

go to the Musem of science and industry in Chicago and watch the giant (1 ton) plumb bob do a Hugh circle around a grid on the first floor I think the cable it's hung from is on the fifth floor, gravity does drift

 

[sparker]

Actually, that is a pendulum showing the rotation of the Earth.

 

[Bc'z]

go to the Musem of science and industry in Chicago and watch the giant (1 ton) plumb bob do a Hugh circle around a grid on the first floor I think the cable it's hung from is on the fifth floor, gravity does drift

After watching a video by @Keith Glasscock on the little itty-bitty velocity variation of a .1 of a grain has on a load i believe ill stick with my 10-10 that resolves a kernel of powder before I go back to the drift of a digital, even if the amount of drift +or- falls within that tenth of a grain.