Equivalent Scale to Gempro 250

[rwj]

I use a 69 grain SMK bullet with a Sharpie mark circled around it, works for me.

I’m more concerned with a scale’s precision (repeatability) than it’s accuracy.

 

[Tesoro]

I never have any concern with this: It will weigh better than most can shoot. No batteries necessary.

 

[Rocketvapor]

Yes it's a 50g.

Something as a check weight close to most of your loads and a small sensitivity weight might be useful. Even with cheap scales full scale is pretty stable.

 

[scissorhands]

Unless you KNOW the true mass of the check weights your results can be expected.
IF your 50 grain check weight was 50.06 grains, and your 20 grain check weight was 20.04 grains then 70.10 would be the expected result.
Check out this thread on relabeled Chinese check weight sets.

Actual weight of Lyman test weights

In January, a relative that works in a lab, called me and told me it was a little slow with everything going on but someone still has to be in the lab, to monitor the balances, as they are on 24/7. I told him I had a project for him to weigh some Lyman grain weights, plus some pennyweight and...

forum.accurateshooter.com

agreed, but I used the same check weight and it weighed different either time.

 

[brokeasajoke]

Something as a check weight close to most of your loads and a small sensitivity weight might be useful. Even with cheap scales full scale is pretty stable.

What do you recommend using for a check weight or sensitivity weight without finding certified weights? I do have an fx120i I assume I can verify. My bench doubles as work/crafts/vinyl cutting bench for the family so I keep the A&D in it's original box a lot and I'm lazy. Heres a good read started by @Rocketvapor

Reducing digital scale drift

I would like to present a method to greatly reduce drift errors when using digital scales for reloading. Specifically load cell (strain gage) scales that always seem to drift requiring recalibration and frequent zero setting. Drift drives the reloader to purchase scales with better accuracy and...

forum.accurateshooter.com

 

[Rocketvapor]

I keep some Check Weights with my A&D EJ54-D2.
1, 1, 5, 10, 10 gram. Bought as ASTM 3, uncertified adjusted using ASTM Class 1 standards. Compared with the EJ54-D2 until I could not tell the difference between the weights.
I can monitor sensitivity pretty well by trickling a couple kernels of powder (currently StaBall 6.5 @ 32.46 grains). I find that calibration does not drift.
I calibrate @ 10 grams on the Low Range, Auto Zero turned OFF in the Menu.
Running off USB power about 4 feet from my modem and see no interference. I monitor Temp and RH only loading when close to 50% RH.
Just finished 98 rounds of 22 Nolser/berber 85.5 loaded LONG.
Saved the last two to make a short video later today for another forum.
Picture of my little reloading corner. Click to go to full size on Flicker.

 

[Rocketvapor]

Reloading video, 2:31 long.
Target is 32.46 grains of SB 6.5 in a 22 Nosler/Berger 85.5, loaded LONG.

 

[Bat Rastard]

I use a 69 grain SMK bullet with a Sharpie mark circled around it, works for me.

Brilliant!
I love a simple solution!

 

[Rocketvapor]

I've heard of people using a Nickel.
Sort of 5 grams, 77.16 grains.
I took one and polished it down to 5 grams.
Weighs the same as my 5 gram check weight

 

[Infrequent Shooter]

Is there a comparable digital scale to the Gempro 250 in the same price range?

Thanks

Same question now. looking for small digital scale. I had an RCBS, thing was a yo-yo. took it back to Cabelas.

 

[Rocketvapor]

@Infrequent Shooter
Ever figure out which nickle was the heavy one?

The first thing one needs to do is figure out what you want the scale to do.
Make a list of weight values, tolerances, and speed of measurement that will make you happy.
Powder charges of 30gr, 50gr, 70 gr? Is +/- 1/10 grain good enough?
Sorting brass, 110gr, 150gr, 200gr, to the nearest 1/2gr?
Sorting bullets, 40gr, 80gr 112gr, 200gr, to the nearest 1/10 grain?
Maybe even sorting a box of 1000 primers to +/-0.02 grains?

The next thing to decide is how much you are ready to spend.
There are scales in the $20 range that might be good enough, maybe $50, $300, and then of course the more expensive ones. Maybe you want a scale with automated charging/trickle. Will it work for all the measurements you want to make? Would a two step weighing 'system' with a dispenser followed by a more precise digital scale? How about a cheap scale for less demanding work and a better one for weighing that really has to be spot on? A beam scale in good condition might work but sorting components would be a pain. A single scale for all measurements in the reloading room might not be the answer.

If your scale is not LINEAR, a full scale calibration without check weights tells you little.
A full scale calibration weight might be required or a digital scale might not complete the calibration but has little to do with accuracy at typical charge weights. Error in a 50 GRAM calibration weight that is 50 milligrams high or low, 49.950g to 50.050g (+/- 0.1%) will likely disappear when weighing powder charges. 30grains +/- 0.1 % due to full scale calibration error is +/- 0.03 grains. Zero drift (seen or hidden), linearity error, resolution and repeatability will likely be bigger than full scale calibration error. That's where check weights come in handy. Accuracy requirements for smaller check weights will be more stringent.
Be ready to figure grams to grains and percent of value. Look up weight tolerances. Better weights may cost more than your scale. Cheap Chinese magnetic steel weights, or old grain calibration sets might not be good enough. Stainless Steel non-magnetic weights of known value and treated gently will last MANY years, even without recalibration.

Good environmental conditions and having known Accurate and Stable (repeatable) check weights NEAR your target is an absolute necessity to check scale performance. You will NEED both check weights and calibration weights. You should probably try to have the ability to CHECK scale performance better than your accuracy requirements for normal use.
Using anything other than a check weight of KNOWN value will BITE you if something happens to the weight and you have to obtain another. Sorting and weighing aren't really the same thing.
Battery power and AC power might help troubleshooting drift and zero problems. Don't be afraid to occasionally hit the Tare/Zero button on cheaper scales.

With a cheapo scale, maybe a 150 pound granite block set in a sandbox, with a power conditioner (not just a surge protector), a wind shield, anti-static wrist straps, barefoot on a anti-static mat, temperature and humidity controlled environment, just might help.

 

[Rocketvapor]

How accurate does your powder charge have to be?
I can't shoot the difference in 0.1grain with my rifle @ 600 yards.
What's an inch here or there when I'm having issues keeping 20 round groups (F-Class) within a 6 inch circle?
Here's what I see with charges, velocities, and calculator drops @ 600.
22N, 85.5 Bergers, and StaBall 6.5. These were 5 shot group averages.
31.7gr 2944 fps 68.8 inches
31.8gr 2967 fps 67.4 inches
31.9gr 2969 fps 67.3 inches
32.0gr 2982 fps 66.5 inches
32.1gr 2996 fps 65.7 inches
32.2gr 3013 fps 64.7 inches

 

[ebb]

There is less about scales that you guys can agree on than primer seating depth!

 

[ebb]

I had bought a Chargemaster long before any of this madness about scales started up and I never looked at the scale you guys were talking about. So tonight I looked at scales. Gem Pro not too many from $20 to $300, A&D 29 pages of them from $96 to almost $20,000. How would you ever make a decision? I know I can do better than a chargemaster but until it dies I am not going down this rabbit hole. I sure hope It never dies!

 

[Infrequent Shooter]

How accurate does your powder charge have to be?
I can't shoot the difference in 0.1grain with my rifle @ 600 yards.
What's an inch here or there when I'm having issues keeping 20 round groups (F-Class) within a 6 inch circle?
Here's what I see with charges, velocities, and calculator drops @ 600.
22N, 85.5 Bergers, and StaBall 6.5. These were 5 shot group averages.
31.7gr 2944 fps 68.8 inches
31.8gr 2967 fps 67.4 inches
31.9gr 2969 fps 67.3 inches
32.0gr 2982 fps 66.5 inches
32.1gr 2996 fps 65.7 inches
32.2gr 3013 fps 64.7 inches

@Infrequent Shooter
Ever figure out which nickle was the heavy one?

The first thing one needs to do is figure out what you want the scale to do.
Make a list of weight values, tolerances, and speed of measurement that will make you happy.
Powder charges of 30gr, 50gr, 70 gr? Is +/- 1/10 grain good enough?
Sorting brass, 110gr, 150gr, 200gr, to the nearest 1/2gr?
Sorting bullets, 40gr, 80gr 112gr, 200gr, to the nearest 1/10 grain?
Maybe even sorting a box of 1000 primers to +/-0.02 grains?

The next thing to decide is how much you are ready to spend.
There are scales in the $20 range that might be good enough, maybe $50, $300, and then of course the more expensive ones. Maybe you want a scale with automated charging/trickle. Will it work for all the measurements you want to make? Would a two step weighing 'system' with a dispenser followed by a more precise digital scale? How about a cheap scale for less demanding work and a better one for weighing that really has to be spot on? A beam scale in good condition might work but sorting components would be a pain. A single scale for all measurements in the reloading room might not be the answer.

If your scale is not LINEAR, a full scale calibration without check weights tells you little.
A full scale calibration weight might be required or a digital scale might not complete the calibration but has little to do with accuracy at typical charge weights. Error in a 50 GRAM calibration weight that is 50 milligrams high or low, 49.950g to 50.050g (+/- 0.1%) will likely disappear when weighing powder charges. 30grains +/- 0.1 % due to full scale calibration error is +/- 0.03 grains. Zero drift (seen or hidden), linearity error, resolution and repeatability will likely be bigger than full scale calibration error. That's where check weights come in handy. Accuracy requirements for smaller check weights will be more stringent.
Be ready to figure grams to grains and percent of value. Look up weight tolerances. Better weights may cost more than your scale. Cheap Chinese magnetic steel weights, or old grain calibration sets might not be good enough. Stainless Steel non-magnetic weights of known value and treated gently will last MANY years, even without recalibration.

Good environmental conditions and having known Accurate and Stable (repeatable) check weights NEAR your target is an absolute necessity to check scale performance. You will NEED both check weights and calibration weights. You should probably try to have the ability to CHECK scale performance better than your accuracy requirements for normal use.
Using anything other than a check weight of KNOWN value will BITE you if something happens to the weight and you have to obtain another. Sorting and weighing aren't really the same thing.
Battery power and AC power might help troubleshooting drift and zero problems. Don't be afraid to occasionally hit the Tare/Zero button on cheaper scales.

With a cheapo scale, maybe a 150 pound granite block set in a sandbox, with a power conditioner (not just a surge protector), a wind shield, anti-static wrist straps, barefoot on a anti-static mat, temperature and humidity controlled environment, just might help.

I am going to use the most precise balance I have this weekend. It is an old Pacific balance with no markings. but very delicate. That will answer the Q. You are a wealth of information on measuring and weighing things. I have a decent group of scales and I think I have a line on a digital scale for quick measuring. Those nickels are my guide post. I have some pretty nice Ohaus check weights in grams. Thank you for your help as always!

 

[Kracken McGraw]

When everyone and their dog are dropping $600 down on a Garmin, crying once for a FX120i may be a smart choice.

 

[JFrank]

I’ve found that huge collections of checkweights are not needed to zero a balance or varify another.
Mine uses a 100 gram F-1 or M-1 to calibrate, I also have a couple of 20 grain check weights that I find more than adequate to stay on track weighing charges to .02 accuracy. ( one kernel )

 

[Infrequent Shooter]

When everyone and their dog are dropping $600 down on a Garmin, crying once for a FX120i may be a smart choice.

Yeah, I agree. that FX120i is a great machine.

 

[Infrequent Shooter]

Does weighing to one kernel show on your target? No. But weighing to one kernel means you are weighing consistently and I guess that is what really counts. Does it matter what the true weight is? No. it only matters that the next time you fire up your machine, or set up your beam, that it weighs the same amount of powder as on the last round. Electronics have a tare button, balance beams have a needle and a level knob as its 'tare'. I always use the same check weight combo as I did for the last time for a particular load. This way I am not starting a new session but just continuing the last one.

One reason I want to use a digital scale is the relative speed vs. poise scale. I am going to weigh my ammo before I shoot to avoid a possible double charge. did that once,, no fun. Good method you use.

 

[rwj]

I am going to weigh my ammo before I shoot to avoid a possible double charge. did that once,, no fun.

Pistol rounds? If yes, check the variation in the bullet and case weights as you may find they effectively mask a double powder charge.