Rcbs scales inconsistent

[RBrush]

.I have 2 RCBS scales. A 5-0-5 and a 750 range master. I haven't been impressed with either. I don't think did anything wrong but, the 5-0-5 always measures up 1.5 grains diffrent rhen the 750 and I had to get a lyman test weight set in order to keep an eye on the 750 because it varies up to .4 grains. My loads range from 10 grains for my 22 Hornet to almost a 100 grains for my 458 lott. I end up rechecking the 750 continously and I have used the lyman weights to rezero the 5-0-5 and have changed out some of the shot under the pan. Is this a normal problem when using such a large diffrence in loads?

[Crashbox]

My RCBS 750 is very consistent. I get the occasional +/- 0.1 grain and a rare +/- 0.2 grain discrepancy with wide weight variation but that's it. I've been quite pleased with its performance.

It is, however, VERY sensitive to any air movement in its immediate vicinity...

Wish I had a solution for you, sorry I can't be of any more help...

[RBrush]

My question is that I'm getting a span equal to your +/- 0.2 which is about .5 grains measured from end to end of the spectrum. Is this accurate enough when loading up varmint or target rounds?

[jaguarxk120]

You should not have to remove any weight from the pan poise that weight is set at the factory. By removing weight you have changed the calibration of the scale. The most important thing is insuring the piviots are clean and the beam is centered in the piviots. Scale is on a level and firm base. If your bench/shelf moves in any way the scale can not weigh anything accurately.
Lastly if you handle the check weight set with your fingers their weight is now in error as the oils/acids from your hands now have coated them.

[stump shooter]

Here's a thought, please read thoroughly.

I have an issue with my 505 and it's not really a big deal...until I want to weigh each charge for a particular rifle.

Once I zero the scale I then adjust it to my desired weight. Using the RCBS weight check kit (I can get within .5 grains of any particular charge weight just fine.) I re-zero/verify my setting. The most I have to adjust is about 1/2turn of the wheel at any given weight. Good enough...I figure there isn't much more than .2 grain variance...who cares.

Now, if I set or remove the pan with enough movement to jar the scale AT ALL...the beam will move on the pivot blocks slightly and/or the wire holding the pan support will move as well. Believe it or not, the scale can change accuracy by 1.0 grains +/-. This is proven with the check kit.

I have developed a surgeon's touch in placing and removing the pan, and check the wire and beam position every so many rounds, ensuring my analness

Considering my experience, perhaps the two scales you are comparing have similar idiosyncracies and this is why you are seeing the difference.

Otherwise, a .2 grain variance would not keep me up a night

[sserdlihc]

My RCBS partner scale is very accurate. I don't run into any issues with accuracy. Did have a calibration problem one time but PACT got me up and running with in 15 minutes.

[DaveInPA]

My 750 is accurate and repeatable. However, it now has an issue where when I press the CAL key to try and calibrate it, it turns off.

The scale is out of warranty. So rather than buy a new scale, I bought a $20 dollar set of check weights. They are anywhere from 0.5 to 20 grains each and the scale is PERFECT every time I check it with those (at the start of every loading session)

[RBrush]

I can honestly say I have only touched the test weights with the twezzers that came with them. I'm another one of the those overly anal reloaders. The 5-0-5 came with my rock chucker supreme kit and it will not set level at zero and be true also at large loads like 50gr and higher. I realize that .3gr isn't much at 50gr but it was off more than .7 at 90gr. I'm wondering if I send it back to RCBS for recalibration. It has to be either the notches are not cut at the right location or the weights they installed are off. I keep a clean no fan reloading area with a solid work bench. I still wonder if the 750 is ok or if I expect too much out of my equipment.

[RBrush]

One last question. Has anyone dumped a few cases back on to the scale 1/2 or 3/4 the way through a batch after rechecking with test weights?

[DaveInPA]

I check my powder charge every 100 rounds (when I refill primers) when loading high volume rounds. I check every charge when loading precision rifle rounds.

[plainsman456]

I have a 5-0-5 and I have only had problems with moving air.I have had to put something under the level wheel once to get it to zero.No problems throwing charges though.

[rottieman33]

I have read in another post if you have florescence lights to close that can effect the scale.

[BDX]

Dave, poke around and see if it has a reset button recessed in the case somewhere. It may not have an exterior accessible one (if there is even one at all) but if it does give RCBS a call and ask how to do a system reset. Just a suggestion based on a few years of practical electronics and instrumentation work.

But then again, if the scale is working with simple weight checks, "don't fix it" as the old adage goes.

[RBrush]

Thank you for all the advice. Hopefully I can get these scale problems resolved.

[MADISON]

Phone or e-mail RCBS about the inconsistency.

[wncchester]

"I have used the lyman weights to rezero the 5-0-5 and have changed out some of the shot under the pan. Is this a normal problem "

No, it's not normal and it sounds like you are creating some problems.

The shot under the pan cover are NOT for "calibrating" the scale, they are ONLY for attaining a rough zero which is then done precisely with the screw at the left end of the scale.

"Test weights" are for testing ONLY, not for the user to adjust anything to.

Any reloading type of beam scale is quite accurate and sensitive forever IF it's kept clean, not abused and is used correctly.

Digitals? Well, some of them seem to be okay. For awhile.

[Dirk00001]

Granted I've only got a single scale, and it's the pricey RCBS Chargemaster Combo, but AFAICT it's just about dead-on and -- although I do so because I'm anal about reloading -- I don't even think I need to recalibrate it during a single reloading session. RCBS as a whole product line is pretty solid IMO (everyone I've ever spoken to about reloading has had nothing but positive to say about RCBS, and most of my gear is RCBS and has served me great), so sounds to me like there's something wrong with your scale.

For the Rangemaster, though, are you sure powder hasn't gotten inside of it? One time I had some Varget get in the hole that the pan plate sits in and, even calibrated, it threw my weights off until I figured it out and cleaned the hole out. Doesn't sound like your issue, but something to check maybe. *shrug*

...but, then again, for any non-TEOTWAWKI situation I can't even imagine using a (good quality) non-digital scale, so I'm probably a little jaded.

[Mike Irwin]

"The shot under the pan cover are NOT for "calibrating" the scale, they are ONLY for attaining a rough zero..."

i.e., the manufacturer's factory calibration, or exactly what jaguar said.

[RBrush]

Well the problem was solved with the 5-0-5. It was not calibrated when it was made. I got the chance to talk to a Rep and he told me that there should have been holes drilled into the back of the 10 grain slide and there wasn't. I sent it to work with a budy of mine and there scale shop calibrated it. I checked it with my Lyman test weight set and found it to be within .1 grain from .5 to 210.5 grain. I'm impressed with what I saw. Hopefully a light shot of air from a can of moisture free dust remover will fix the 750. It says it's good for electronics. I wondering if anyone has done this because I don't want to be the first one to experiment?

[wncchester]

"... exactly what jaguar said. "

Granted. Given the volume of chatter, it sometimes seems worthwhile to reaffirm a valid statement. ??

Glad to hear the scale has been corrected. Seems more than a little odd they would not have caught that in a Q.C. check but guess no maker is perfect.

[Unclenick]

Considering they're made (our used to be, anyway) by Ohaus, that is positively shocking. Probably been farmed overseas.

Don't know about the canned air. It won't hurt electronics, per se, but don't let it blast the load cell; just the switch that isn't working.

At this time of year, there are problems with static electricity and scales, too. Ground everything, including beam balances, if humidity is low at your place?

Electronic scales can pick up noise through the air (large fluorescent fixtures) and through noise put on the AC by fluorescent lamps and other sources. On an another site, one of the moderators started plugging his scale into a computer UPS and it stopped drifting. Line filters can do that even better. Look for a powder strip that has both surge protection and EMI filtering if the price isn't too high for you? You can buy the plain filters for one to two ampls for as little as $10, but you'll have to wire them. A ten amp filter adequate for a whole power strip can be had for about $16.