OK I am kinda poor at keeping records and cannot find proof positive, but I am really sure my load for a 308win that I own is 41 grains of win 760. But its been a while and i cannot find it in my load book. So I pulled the bullets on a few and weighed the powder charge. One was 40.6 and the other was 39.9+ almost 40. the charge came from a very old Chargemaster that has been well taken care of and never given me any doubt till now. I follow the RCBS calibration sequence every time I turn it on and if I take a break for dinner or something unexpected, I recalibrate it again before I start up. When i first got it I checked it constantly and it was always right on, now i am unsure if it has gone bad or not. I got out my best RCBS balance beam scale and will go to Scott Monday morning. What do I do about the Charge Master? I don't know if I can reload without it. What do i do to make sure it gives out a consistent charge weight? Ive heard of the CMs dyeing, but this works as good as new. Has it always thrown way off and I never knew, or has it deteriorated with age?
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Coyotefurharvester
Silver $$ Contributor
41 gr is well under starting charge weights of W760(Hodgdon site). Was this a service rifle, or heavy(190+gr) bullet? Did you have W748 or some other ball powder.
At what value do you CALIBRATE the ChargeMaster?
As jelenko stated, a check weight or two near the charge weight is the minimum required accessory for accurate weighing.
An ASTM Class 4 or better 1 and 2 GRAM check weight (gives you 1, 2 and 3 grams) is better than a full scale calibration.
As jelenko stated, a check weight or two near the charge weight is the minimum required accessory for accurate weighing.
An ASTM Class 4 or better 1 and 2 GRAM check weight (gives you 1, 2 and 3 grams) is better than a full scale calibration.
wvlongshot
Gold $$ Contributor
So you pulled down ammo to recheck powder weight? There could have been kernels left in case stuck to walls or lost some in process. You need to weight out new charges and check repeatability with the chargemaster against another scale.
I know nothing at all about charge master's (CM) having reloaded for over 50 years using a simple but quality beam balance.
I am on my second beam balance, a Lyman Brass Smith. I check every 3 months with weight standards over the range I use the balance. Typically, the balance is within + or - 0.1 grain as advertised so your charge variations seem excessive.
You said you can't reload without the CM. Unless you are a high volume reloader, I don't see why a beam balance wouldn't work for you. If you are using a ball powder, these meter very well from a powder measure, and you only need to spot check charges, not weigh everyone.
Quality beam balances are very robust - they last a long time if you take care of them. You should be able to pick up one at any local gun shop that sales reloading equipment or you could order one from Midway and have it in a few days with express shipping.
I am on my second beam balance, a Lyman Brass Smith. I check every 3 months with weight standards over the range I use the balance. Typically, the balance is within + or - 0.1 grain as advertised so your charge variations seem excessive.
You said you can't reload without the CM. Unless you are a high volume reloader, I don't see why a beam balance wouldn't work for you. If you are using a ball powder, these meter very well from a powder measure, and you only need to spot check charges, not weigh everyone.
Quality beam balances are very robust - they last a long time if you take care of them. You should be able to pick up one at any local gun shop that sales reloading equipment or you could order one from Midway and have it in a few days with express shipping.
I would also question your balance beam scales.
My carefully tuned loads had gone 'off song' but when my new CM arrived and initially tested it was apparent my previously trusted beam scales were in need of some TLC. Once the agate anvils and knife edges were thoroughly cleaned and adjusted it agreed with the CM.
YMMV.
As stated above the better balance beam scale is going to Scott Parker Monday morning. Just used to it K22, I reloaded for years with a balance beam scale, and own 2, but haven't used one in a long while. A charge master has a built in calibration cycle, you press 0 and the computer answers back that the platen has nothing on it and calibrates the zero, then it asks for 50 and I use one of the provided 50 grain weights and after it checks it says OK and asks for 100 and I add the other 50 grain weight that is provided and it checks and sets the 100 check. This is the only procedure that is mentioned in the manual to set scale to a check weight. the fact that the charge weights were off so far scares me into thinking some thing has failed. When i first started using it I checked constantly but it was always very close of dead on and over the years just trusted it and stopped looking.
Coyote, What you said startled me. So i looked at Hodgdon's site like you said and there is no mention of using WIN 760 with a 168 grain bullet, in fact the only WIN powder mentioned for 308 was Staball match. But if I looked up 260 Remington there is data for 760, and also for 30-06 with a 168 grain bullet. I also looked in one of Hodgdon's annual manuals, i have one for 2018 and it doesn't list 760 for 308 WIN either. I never invent a load and this came from listed data at the time is started developing it. I imagine they get more money for Staball match and remove WIN 760 data so as to sell the more expensive powder. The rifle is a Ruger 308 VT and has never shot very well but did OK with this mild load of WIN 760. I would match it against anything for a cold bore shot, always dead in the middle at 100yds. but it usually doesn't take very many more shots to be ugly. But 2 weeks ago it shot 3 that were in a group that was small and and 2 in another group that was one hole. And some times that can be fixed.
"then it asks for 50 and I use one of the provided 50 grain weights and after it checks it says OK and asks for 100 and I add the other 50 grain weight that is provided and it checks and sets the 100 check."
The Chargemaster uses grain or gram calibration weights?
The Chargemaster uses grain or gram calibration weights?
SSL
Gold $$ Contributor
Have you just tried running various weights through your ChargeMaster and then checking them against a known accurate scale? Right now, without your records, you are trusting your memory that those weights are that far incorrect and (as mentioned by @wvlongshot ) how sure are you that you are truly getting all of the powder out of those pulled loads to weigh? A little humidity can cause powder to cling inside cases.
It appears that I don't own a known accurate scale, if the chargemaster is not. Just hope S Parker can get me back in business. The scale going to him is better than the one I used before the chargemaster so I will look up the one I used back in the day. It's around here somewhere in the factory box. Rocket vapor it comes with 2 weights that are marked 50g they are what was designed to calibrate the scale. To be honest I do not know if they are grains or grams now that you have asked me to think about it.
The 50g weight is 50 grams (about 771.6 grains).
You are "Calibrating" @ Zero, 771.6, and 1543.2 grains.
Not anywhere near 41 grains and not a good check for load accuracy.
In addition to not knowing charge accuracy, you may have an issue with repeatability (40.6 to 40gr).
A 55gr bullet, weight not accurately known, should be repeatable.
Even a penny can be used for repeatability.
You are "Calibrating" @ Zero, 771.6, and 1543.2 grains.
Not anywhere near 41 grains and not a good check for load accuracy.
In addition to not knowing charge accuracy, you may have an issue with repeatability (40.6 to 40gr).
A 55gr bullet, weight not accurately known, should be repeatable.
Even a penny can be used for repeatability.
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Highpower-FClass
Gold $$ Contributor
I owned and used a Chargemaster and used a check weight. I then bought an AD FX 120i scale and started checking every weight thrown by the Chargemaster on the 120i and it was enlightening.
The Chargemaster does not throw charges with a high degree of accuracy. If the CM was set to 44.5, then 10 charges that all show 44.5 on the CM could be off by as much as +/- 0.5 grains when weighed on the 120i.
The scale in the CM is not very accurate. It will state that the target weight has been reached but the actual weight of the thrown charge can be different from the target weight.
In many cases the difference is small enough to where it does not matter, but if preciseness is desired, the CM does not do the best of jobs
The Chargemaster does not throw charges with a high degree of accuracy. If the CM was set to 44.5, then 10 charges that all show 44.5 on the CM could be off by as much as +/- 0.5 grains when weighed on the 120i.
The scale in the CM is not very accurate. It will state that the target weight has been reached but the actual weight of the thrown charge can be different from the target weight.
In many cases the difference is small enough to where it does not matter, but if preciseness is desired, the CM does not do the best of jobs
I check every charge on a rcbs range master or a Dillon digital scale before using that charge... I love my charge master it's normally pretty darn close or it says over or under..... Try wiping down your charge master and all digital scales with a dryer sheet before using it.... Static electricity makes them do dumb stuff... Also let them have time to be turned on for awhile and let them get used to the room temperature...
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