Rcbs chargemaster issues

[HuntHarder]

Just wanted to share how my chargemaster appears to not be as accurate all of a sudden. About a year ago, I double checked my chargemaster using a buddy's fx-120. It appeared to be weighing each charge pretty damn close to the fx120.

Knowing my chargemaster was functioning properly, but reading about others not, I still opted to double check some of my loads on my rcbs balance beam scale. I typically check maybe 1 in every 5 or so loads to verify it is still throwing accurately. I have never noticed anything alarming.

On Friday, I noticed my ES was higher than this gun normally shoots. When I returned home to start reloading, I decided to check EVERY powder throw from my chargemaster. I noticed that maybe 1 or 2 out of 10 would be off up to .2 grains from my desired charge weight. The only thing that really changed on my reloading bench has been the temperature. It has been a little chilly the last couple loading sessions. Atleast for Arizona standards.

This am I shot the rounds that I checked the charge weight of every round. My ES came right back where it used to be or maybe even slightly better. Im not sure if it was the colder weather, or if the scale just decided to not be accurate. It has also been extremely dry here and im thinking it could be excess static electricity. I'm not on the cause. Just another heads up to not fully trust your Chargemaster. I now am going to check every round on the beam balance until I upgrade.

 

[JF_Idaho]

To be fair the accuracy of the CM is .2 grains. +.1/-.1 on the extreme spread. Wipe it down with a dryer sheet and make sure there not static, warm up for an hour or more.

 

[HuntHarder]

I usually let it "warm up" for 30ish minutes but have never worried about static electricity. I was only shooting 100 yards, so accuracy wasn't an issue. Honestly, if I didn't have this Garmin, I probably would have never noticed anything. Just having 5 shots out of 40 that were way out compared to most caught my eye. Almost 110fps swing from high to low on those 4.

 

[rayporter]

many things can mess with a scale, be it a CM or FX. you must pay attention.

air currents and movement of the table are very serious on any scale. static, too.

temps? i have used my CM in all sorts of temps reloading at the range from michigan to florida when shooting matches. i also see many CMs set up and never hear of temp issues.

i can take mine out of the box and plug in the battery i carry in the box and add powder and the check wt will read 29 gr. every time and all day long.

a bud was having trouble once. he said he had sent in 3 CMs not working. after watching him load i suggested he not touch the table that he was leaning on while the CM dropped powder. his troubles went away.

 

[HuntHarder]

I think I'm over 5 years of owning mine and never an issue that I've noticed. Ill keep an eye on it and see if I can narrow down the issue. Nothing has changed on my bench. Like I said before. Had i not been using my Garmin on every shot fired, i would have never noticed a thing. Up until I got my garmin, a year or so ago, I would only check velocity to get accurate bullet drops or during load workup. Now I pretty much capture every shot.

 

[freezerfull]

To be fair the accuracy of the CM is .2 grains. +.1/-.1 on the extreme spread. Wipe it down with a dryer sheet and make sure there not static, warm up for an hour or more.

This is spot on. My CM is about 8 years old. What I have come to learn if you want consistent charges and low SD/ES you gotta run every charge across a balance beam and fine tune. I often set the CM .1 grains short and trickle up to exact charge on a BB scale. The benefit of the CM for me is it substantially speeds up the process of getting the bulk of charge weighed out. While I fine tune a charge on the BB the CM is running out another load for me.

 

[Weldor]

Mine floats alittle when it is colder also. I noticed last week when it was a little cooler.

 

[pertnear]

I’ve been a powder-measure/beam-scale/trickler my whole life until buying a CM about a year ago. I’m not a long range competitor but accuracy, consistency & precision are still important to me. Of course I checked my CM when I first got it against my beam scale. I was pleased, as they were very close. I’ve read internet blurbs about warm-up, no fluorescent lights & treat the CM as gently as nitroglycerine. I always warm it up before using although I question what warming up is – the transformer? The unit itself has a liquid screen & a led(?) My press is mounted on the same bench that the CM sits on. My bench is very sturdy, attached to the wall & concrete floor. I will sometimes seat a bullet while the unit is dispensing the next charge rather than wait for a block of cases to be filled. The things I don’t like about the CM is fully emptying the hopper & trickle tube. To get it all out involves tilting , tapping etc. to get every bit of powder out. I hear a vacuum near a electronic device is a big no-no so no dust-buster for final clean-up. Adjusting the flow for various powders types & quantities takes quite a bit of parameter settings & some trial & error. As best I can tell, there is no way to save these settings between uses(?) I guess I have a love/hate relationship with my CM.