Beam Scale Incosistencies

[whoami-72]

Alright, I found an old USA made RCBS 505. I get why everyone says they're really sensitive because I can watch it move with individual kernels. However, I've found that while reloading I'll bump it, set the pan on to hard, take the pan off to fast, etc and it will be slightly "out of tune". When I try and verify I didn't bump it off from 0 it will often be .05 or .1 grain off in either direction (total swing of .2) with an occasional wild one of + or - .2 grains (total of .4). I find it incredibly frustrating and slow to have to rezero it or even wonder if it needs to be rezeroed every 5-10 powder charges.

What have you guys done to ensure it consistently stays zeroed over a lot of powder reloading? Obviously it would be nice to never bump it but even during normal use I'll still find it drifting. I'm going to try completely cleaning it and seeing if I can create "padding" to prevent it from shifting while pulling the pan off and back on.

 

[Grizzle]

I think, at least in the case of mine, that its so sensitive that the varience looks worse than it is. One kernel of powder is enough to move it from just above to just below the reference line, it has frustrated me in the past when I've over analyzed it but it hasn't stopped me from getting acceptable results yet.

 

[Grizzle]

But to answer your question I zero it with a known weight when I start then just be gentle as I can be and run it. Either way it's more accurate than volumetricly thrown factory ammo, and good enough for my needs until I ante up for a good auto trickier.

 

[wapitibob]

I clean mine, make sure the knife edge is good, position it, use charge weight check weights to zero at that charge weight, and never touch it again other than carefully setting the pan on it. I use N570 and will occasionally have to cut kernels in half to make weight.

 

[whoami-72]

I clean mine, make sure the knife edge is good, position it, use charge weight check weights to zero at that charge weight, and never touch it again other than carefully setting the pan on it. I use N570 and will occasionally have to cut kernels in half to make weight.

what do you mean by knife edge?

 

[whoami-72]

But to answer your question I zero it with a known weight when I start then just be gentle as I can be and run it. Either way it's more accurate than volumetricly thrown factory ammo, and good enough for my needs until I ante up for a good auto trickier.

being gentle is so hard lol

 

[wapitibob]

what do you mean by knife edge?

The beam pivot point is a knife edge for minimal contact/resistance.

 

[SDHNTR]

Don’t bump it. Sorry, I couldn’t resist but that’s the only answer if you don’t want to rezero it afterwards.

 

[whoami-72]

Hahaha my problem is even during normal use of just lifting up the pan and putting it back on it will shift slightly.

Although, thanks to the knife edge comment I think I figured out why

 

[danhuntingmi]

As you've insinuated, there's often a tradeoff between apparent accuracy and consistency where apparently seeing much more accuracy than you need (<0.1 grains) is not repeatable.

One of the biggest thing about beam scales is 'parallax' where holding your head differently will change the apparent reading of the scale. Some people put cameras on their scales for this reason. If you do a Google search, there is no doubt a long list of things to do to increase the repeatability of beams scales.

That said, I would not worry about it unless you're trying to set the next 1000 yard record.