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.