Weighing vs metering powder

[tlk]

I have read about how FGMM loads vary quite a bit by weight but are consistent from shot to shot. The comment has been made that they are metering their charges, not weighing them.

Out of curiosity and ignorance on my part, how would one meter a charge?

Thanks.

[rscott5028]

Lee includes a dipper with their dies and load data based on the number of scoops. ...just like measuring flour to bake a cake.

There are also powder dispensers available with a handle that you toggle up and down to fill and dump a hopper that's adjustable via a screw.

Such setups are often used with progressive presses when volume shooting is more important than actual precision. By that, I don't mean it can't be precise. Rather, it's more frequently used in that manner. ...and, much more so with shotguns and pistols.

-- richard

[Joe King]

Makes me wonder what their definition of "consistent" is

[Kevin Thomas]

tlk,

This sounds like a terminology issue, as I'm not aware of any commercial maker that actually weighs their charges priot to dropping them. I don't know whether Federal is plate loading or using an in-line system, but the charges are almost certainly dropped via a measure, or "meter" which is (I suspect) where the confusion here comes from.

Richard has explained this, and I'll go with his explanation completely. I have seen Lake City weigh their ammo, and they still do this as a regular part of their inspection process. The purpose there, however, isn't to ensure the precision of a charge weight, but to guarantee that each round has enough powder inside to postively assure that it can't stick a round in the bore. Very bad form in combat ammo, and makes for very unhappy troops!

[tlk]

Thanks for the info guys. Mystery revealed. I have those same tools Richard - I can see where the weight variance would come from.

Based on a 30 cal cartridge I can see how it could be considered consistent inside of an acceptable window.

[rscott5028]

I have a police sniper buddy that shoots the 168 FGMM ammo ~.5 MOA at 500yds. Not bad for factory metered ammo.

I've shot Lapua 6br loaded ammo better than that and from what Kevin stated, it's likely a metered charge as well.

-- richard

[MT4XFore]

Interesting question. I do both. For my large cases used for big game, I weigh each and every charge using an RCBS chargemaster. For my varmint loads I use an RCBS benchrest powder measure. I set the measure up using the scale on my chargemaster. I will load 10 or 20 rounds, then check the measure on the scale to make sure it is still throwing the correct amount. If it isn't I will adjust it, but it is never far off. I found that if you move the powder baffel down in the measure hopper as far as it will go, the measure will throw extremely consistent loads, depending on type of powder used. I am using Ramshot ball powders for my 22-250AI and my 223AI. Those powders measure like water! Very easy to get consistent loads. I have read where "volume" is actually more important than "weight" when it comes to powder loads. I cannot comment on that as a rule, but my 22-250AI shoots 1/2" groups consistently at 200 yds. using thrown powder charges. If I miss a prairie poodle its because I didn't do my part, not because of my equipment or ammo.