Charge Master accuracy check data.

I venture to say most experienced hand loaders are using an RCBS Charge Master, and for good reason. For what they cost, they can really speed up throwing powder charges, with decent accuracy. It is a machine that moves the hand loader towards some form of automation. I will forever have work for mine to do, so this is in no way an attempt to degrade the machine. Over the years I have moved from:

Manual thrower/ RCBS Range Master/ RCBS hand trickle to final.

RCBS Charge Master (only)

RCBS Charge Master, RCBS 5-0-5 beam scale, hand trickle to final.

A.N.D. FX-120i, Autothrower, Autotrickler.


The A.N.D. is accurate to .02 gr. Which is essentially, accurate to the single kernal of many powders. There literally is no farther we can go in accuracy of measuring powder charges, unless someone wants to go three places right of the decimal, and are also prepared to chop some powder's kernals in half. I believe that would be taking things too far (if there is such a thing in precise hand loading).

Today, I was set up for my Charge Master to throw 2.2 gr below final desired charge, move the pan, and have the Autotrickler finish the remaining charge, tied to the A.N.D. FX-120i. Final load was to be 69.2 gr. Powder is H-Retumbo, all scales had been powered up for 4 hours prior to this, and they were operating at 75°F, with little to no wind currents.

Here is the summary of the Charge Master's throws, programmed to throw 67.0 gr. This is for throws 65 through 100, today.

Minimum 66.94 gr, -.06 gr of desired (pretty good)

Maximum 67.26 gr, +.26 gr of desired

Total spread of error .32 gr.

From 66.94 gr to 67.04 gr X 16 throws
From 67.06 gr to 67.16 gr X 14 throws
From 67.18 gr to 67.26 gr X 5 throws

Of course this is plenty accurate for many loading jobs. Plinking ammo, with some consistency, AR ammo that .32 gr that might be "good enough".

Will this win bench rest? Doubt it, but I won't bet against an expert at the task. Would this win PRS? Guarantee is has before. Will this work for hunting and shooting animals short, medium and long range? Guaratee it has before.

For those "chasing the dragon" seeking super consistent shooting ammo this can be improved upon, inexpensively, some what expensive, and very expensive. The least expensive method I am aware of are quality beam scales. They take a discriminating eye, but they can charge powder to very tight tolerances. For the right eyes, they may be to the kernal. But the process can be slow. For thousands of rounds, I've used the Charge Master to throw .2 gr below desired, move the pan to a beam scale, hand trickle to final. 1 minute per powder charge and loaded case.

The medium expense method is what I have just started using, the Autothrower, followed by the Autotrickler on the A.N.D. scale. 22 to 24 seconds per powder charge and loaded case.

The expensive method would be a Prometheus scale and auto loader. I have never operated one, but have seen video. It is precise to the kernal, and it is fast, but at a high price.

Should every hand loader own and use a Charge Master? In my opinion, yes. But I wanted everyone to realize its' limitations.

This also supports the need for ladder testing, in some situations. In a ladder test a "good shooting load" can have a powder spread of .6 gr and still print the same POI 500 yards, plus. .6 gr is half of what the Charge Master is capable of.

I’ll just chime in...imo the gem pro is great for secondary checks but is not good enough to load on. There is too much lag and drift on measurements


I wish I would have gotten in on the scale sale earlier this year

Are you using the brass restrictor insert, the soda straw method, or none of the above?

Brass insert.

I contacted the original maker, and asked for his dementions, explaining that I was not competing with him, just had the ability to make one myself. He graciously shared, and I turned one out of brass, in the lathe.

Thank you. More questions...

From 66.94 gr to 67.04 gr X 16 throws - I would assume the scale was displaying 67.0

From 67.06 gr to 66.16 gr X 14 throws - but here, was the scale displaying 67.1, or was it lying to you and saying it was 67.0?

From 67.18 gr to 67.26 gr X 5 throws - and here, was it liar, liar pants on fire, or was it displaying 67.2 / 67.3?

I think "From 67.06 gr to 66.16 gr X 14 throws" is a typo.

The scale lied most of the time. Out of all those, I recall five that the Charge Master did read .1 to .2 gr heavy.

Should have been 67.06 gr to 67.16.

I'll edit.

Interesting test. The chargemaster is good enough for me though.

Love mine. Per the guy I talked to at RCBS, I always check the level on mine and I've removed one of the rubber feet on the scale. Those two mods along with the brass insert seemed to make quite a bit of difference. I'm not shooting in any matches, and hey, I've got a built in excuse if one gets away from me.