Inaccuracy of Beginner Scales

[titanxt]

Having read the other thread about the $1,000 scales that measure to the kernel, I got to thinking about how inaccuracy of my Hornady basic reloading scale. This is the model I have:

Any idea what the +/- margin of error might be on this type of scale? Keeping in mind that I am loading for factory rifles, how much scale do I need? There there a scale in the $100 - $200 range that will fit my needs? If not, what kind of price range are we talking about?

Thank you!

Andy

 

[chkunz]

Buy or borrow a set of the scale check weights and do a calibration over the range that you use the scale for. I have found the beam balance scales to be very accurate and within +/- 0.1 grains which is good enough for most folks that shoot competition even the High Masters. There are a lot of reports that show that accuracy is tolerant of that level of accuracy in powder measurement.

 

[fdshuster]

As said, get a set of scale weights and use them before each session of using the scale. Keep the scale in the same position on your bench, all the time when weighing & keep it covered when not in use.

Use a small soft bristled brush to keep the V notch's clean & you will get years of dependable use out of it, without the frustrations of electronic.

 

[Patch700]

If you aren't shooting long range save your money... Put it towards things like better glass or a good front rest.

 

[sparky123321]

Even though I now use a very expensive analytical balance(0.002gr), in the past I found standard mechanical balances(rcbs, hornady, etc) much more accurate and repeatable when compared to any 0.1gr digital scales under say $200-$250. There are more expensive magnetic force 0.02gr scales that are extremely accurate and repeatable, but they run in the $500-$1,000+ range.

How much of a difference + or - 0.2gr is going to make in your ES is debatable, but it will be more so with lighter charges.

 

[people]

A quick test to see how accurate your scale is put in a bullet and see what its weight is. I had a Lyman that would not weigh the same 115gr 9mm bullet the same two times in a row.

 

[Danattherock]

Be careful weighing bullets and judging your scales. My buddy weighed a bunch of 77 SMK the other night and they varied far more than I would have thought. 3-4 tenths from end to end as I recall. Ironically, the smallest batch? Yep, 77.0 gr.

I'm happy with my RCBS 502. Use a Chargemaster too and love it. Would take a far better shooter than I to benefit from a scale that will detect half tenths and single kernels of Varget. I've got bigger fish to fry and 1/10 gr accuracy is fine by me. You might also read the Houston warehouse test, or similar name.


Dan


Found it...

http://precisionrifleblog.com/2013/10/18/secrets-of-the-houston-warehouse-lessons-in-extreme-rifle-accuracy/


Read the whole thing (after you start a pot of coffee). But this is the line I was referring to...

Powder charges, as long as they were fairly consistent and bracketed within a couple of grains, were not important. He threw all of his charges with a Belding & Mull powder measure, and for one experiment he shot groups using three different powder measure settings (51, 52 & 53) … all three groups were identical.

 

[people]

Yup but if you weigh the same bullet it should be the same every time no matter the weight of the bullet.

 

[Danattherock]

read your post again, are you referring to a scale drifting? I'm pretty new to all this. My 502 confirms my chargemaster, which makes me fairly confident. But I've heard of some crazy scales out there. Prometheus ?


Dan

 

[BoydAllen]

I have tuned several RCBS scales, earlier ones, of American manufacture, with good results. A friend bought some new Hornady reloading equipment, including a scale that is identical to yours, which I borrowed for a day or two, to see if I could tune it like I had the RCBS scales. I could not. I think that the reason is the bearings that the knife edges sit on. I believe that with sharpened knife edges, that the agate bearings that my RCBS scales have have less friction. The good news is that the latest scale that I purchased, and tuned, was very inexpensive. I got it used off of Ebay for less than $40. It is a 505 and with magnification I can easily see a half of a tenth, and it repeats well. Having said all of that, accuracy is a weakest link thing, and unless you have all of the other things that could be holding back your accuracy resolved, don't worry about a better scale, since any potential difference will get lost in the noise.

 

[Boxcar77]

Be careful weighing bullets and judging your scales. My buddy weighed a bunch of 77 SMK the other night and they varied far more than I would have thought. 3-4 tenths from end to end as I recall. Ironically, the smallest batch? Yep, 77.0 gr.

I'm happy with my RCBS 502. Use a Chargemaster too and love it. Would take a far better shooter than I to benefit from a scale that will detect half tenths and single kernels of Varget. I've got bigger fish to fry and 1/10 gr accuracy is fine by me. You might also read the Houston warehouse test, or similar name.


Dan


Found it...

http://precisionrifleblog.com/2013/10/18/secrets-of-the-houston-warehouse-lessons-in-extreme-rifle-accuracy/


Read the whole thing (after you start a pot of coffee). But this is the line I was referring to...

Powder charges, as long as they were fairly consistent and bracketed within a couple of grains, were not important. He threw all of his charges with a Belding & Mull powder measure, and for one experiment he shot groups using three different powder measure settings (51, 52 & 53) … all three groups were identical.

Thank you thank you thank you for posting that article!!! It was an excellent read.

 

[smoooth]

Expanding on what was previously mentioned about weighing a bullet, as well as the check weights. Select a bullet, weigh said bullet - a few different times to be sure the readings are repeatable. Now, write down the weight of that particular bullet and save that bullet as your check weight. Meaning each time you sit down to load, grab THAT bullet and weigh it to be sure your scale is still reading accurately and repeatably. You can take this a little farther by picking a bullet of a weight near that of your charge weight, example: 52gr HPBT .22 cal bullet is near the 48.5gr load of powder XXXXX for your 284 Win. These methods will help maintain that accuracy level and consistency within the limits of your equipment, whatever it may be.

Also, when using any balance / scale, make sure the room is free from drafts or temp changes as they can significantly alter your readings.
Owning super expensive equipment is utterly pointless if you don't have the knowledge or skill level to use it properly.

Best of luck!

 

[ireload2]

I used that same scale marketed by Bair for about 20 years.
It is a superior scale to most of the cheap stuff on the market.

Keep it clean and it will do all you need for reloading rifle cartridges.

 

[titanxt]

Thank you very much, you guys are great! I also like the fact that I dodged spending some money and learned a lot to boot!

Thank you,

Andy

 

[suberjc]

I have and old Lyman / Ohaus. Looks like the current RCBS 505. I use it after throwing low into an electronic auto charging
thingey for the final trickle.
It's given me some pretty fair results in competition.

 

[CatShooter]

Andy.

What you need is not accuracy. What you are looking for in a reloading scale is repeatability.

If you have a bullet that weighs exactly 95.0000 grains, and your scale says it weighs 94.50, and it says exactly the same for ten weighings, then the average for the group is the same as the single weighing... it is repeatable.

But if the scale has sticky bearings or something that rubs or binds, and it reads 94.63 - 95.37 - 94.75 - 95.25 - 95.03 - 94.97 - 94.32 - 95.68 - 95.53 - 94.47... then the scale is more accurate (in the long term), but not repeatable.

Whether your powder charge weighs 45.2 or 45.6 means nothing, as long as all the powder charges are the same. Because you start low and work up, the scale could be calibrated in any kind of units - it would make no difference.

If you had a loading manual that listed loads in tinks, and a scale that was calibrated in 1/30th of a tink, and your max load was 63 tinks, and your starting load was 57 tinks, would it make any difference... as long as the scale gave the same weight every time.

You don't need a scale that is accurate to 0.001 grains - a single granule of Varget, 4350, etc, weighs 1/30th of a grain, and a decent beam will resolve that, repeatedly.

My Lyman M-5 (35 years old) will move and repeatedly resolve one granule of H-322 (0.0058 of a grain) easily, but it will not weigh it - but I don't need to know the weight of a charge to 95.0058 which is 1/17th of 1/10th of a grain - I need repeatability to ~1/4 of 1//10th of a grain, which is easy. I am happy knowing that there is no drag and the scale is fine.

The $600 electronic scales are not without their problems, so don't get anal about it and buy an expensive headache.

 

[titanxt]

Catshooter,

That makes a lot of sense. I will check it for consistency.

Thank you!
Andy

 

[1066]

Andy - The scale you show is the Hornady/Pacific model "M". One of the "Good" scales and capable of excellent accuracy and consistency. It will be well worth persevering with and better quality than any new beam scale you could buy today.

The "M", although it looks a little agricultural, is a fairly large, solid scale with a heavy cast iron base. It has good magnetic damping and a three poise beam with very positive locating notches and beam markings.

The Hornady knife edges are quite massive when compared with RCBS/Lyman type scales. The knife edges on the Hornady scale work slightly different from the RCBS type scales. On the RCBS range there are small endplates the hold the agate bearings in place, these also act as endstops for the knife edges.

If the knife edge is contacting the endplate this could lead to a source of friction - this can't happen with the Hornady system. One side of the knife edge on these scales is crescent shaped which keep the beam centred with no friction.

There are only really two points to look at on these scales - the knife edges need to be sharp with no burrs and the panhanger stirrup need to be hanging free in the centre of it's own little knife edge.

A good clean with a toothbrush and some sort of spirit and a look at the edges with a good eye glass and your scale should be good for another 20 years before it needs looking at again.

Here's a short video I made comparing the new Hornady beam scale to the older one. I'm sorry the sound quality is poor.

https://www.youtube.com/watch?v=buRAm2aL6ik

And here's one I tricked out a bit.

 

[dixieppc]

Andy - The scale you show is the Hornady/Pacific model "M". One of the "Good" scales and capable of excellent accuracy and consistency. It will be well worth persevering with and better quality than any new beam scale you could buy today.

The "M", although it looks a little agricultural, is a fairly large, solid scale with a heavy cast iron base. It has good magnetic damping and a three poise beam with very positive locating notches and beam markings.

The Hornady knife edges are quite massive when compared with RCBS/Lyman type scales. The knife edges on the Hornady scale work slightly different from the RCBS type scales. On the RCBS range there are small endplates the hold the agate bearings in place, these also act as endstops for the knife edges.

If the knife edge is contacting the endplate this could lead to a source of friction - this can't happen with the Hornady system. One side of the knife edge on these scales is crescent shaped which keep the beam centred with no friction.

There are only really two points to look at on these scales - the knife edges need to be sharp with no burrs and the panhanger stirrup need to be hanging free in the centre of it's own little knife edge.

A good clean with a toothbrush and some sort of spirit and a look at the edges with a good eye glass and your scale should be good for another 20 years before it needs looking at again.

I have a set of vintage Ohaus 10-10 scales made in the USA prior to their moving production to Japan. A few months back, I shipped those scales to Scott Parker in California for a complete tune job. I was amazed with its capabilities when it returned. It is extremely repeatable and will indicate the dropping of a single granule of powder. It would cost me literally hundreds of dollars to get a digital scale with that level of repeatability and sensitivity. I've returned to old school which has rewarded me with the return of my confidence in my equipment.

I think a lot of people underestimate the capabilities of a well tuned balance scale.

Regards.....

 

[Brians356]

Beware static electricity! A beam scale is very sensitive to static.

In dry Nevada, the winter cool/dry air makes for static in the home, but static is possible all year round. I learned I have to take my shoes off and let my stocking feet touch the carpet while using my RCBS/Ohaus 505 scale. If I wear shoes, I can zero the scale, then levitate it off zero by simply hovering a fingertip near (but not touching) the pan! Like getting two positive (or negative) poles of magnets near each other.

In addition to going shoeless, I wipe the scale, the pan, my powder bowl, dippers, and the bench under everything with a Bounce laundry anti-static sheet.

Also, air currents are deadly. Best to turn off the HVAC or close any HVAC vents in the room. Don't let other people move around nearby. If you have a desk lamp hovering over the scale, turn it on and let the scale reach its new temperature for a haf hour before zeroing it.

I like to throw charges into the pan a little short (from a Lee powder dipper) then trickle up to the mark, every time. If I overshoot the mark from the dipper, I empty the pan and start over - never remove grains from the pan to come down to the mark.

As the session progresses, I go back and re-weigh contents of cases loaded earlier, to see if the scale has drifted.