Jump to content
308AR.com Community
  • Visit Aero Precision
  • Visit Brownells
  • Visit EuroOptic
  • Visit Site
  • Visit Beachin Tactical
  • Visit Rainier Arms
  • Visit Ballistic Advantage
  • Visit Palmetto State Armory
  • Visit Cabelas
  • Visit Sportsmans Guide

The in & outs of Metering Powder Charges


survivalshop

Recommended Posts

    I have found that my Redding Powder Charger with Ball type Powders is very consistent , never used the type of " click " adj. this Arthur is speaking of . When I use the stick type Powders , like IMR 4064 , I get close with the Powder measure & trickle Powder to get the exact weight & I use a Pact digital Scale for weighing , so they are all exact . Ball types are so close with just using the  Redding Powder Charger , no need to weigh each charge , just check once in a while .

 

THE INS AND OUTS OF METERING CHARGES

Facebooktwittergoogle_plusredditpinterestlinkedintumblrmail
Facebooktwittergoogle_pluspinterestyoutube

This is a specially-adapted excerpt from the forthcoming book, “Top Grade Ammo,” by author Glen Zediker, owner of Zediker Publishing. Click here to order from Midsouth.

by Glen Zediker

Most reloaders are going to invest in a powder meter. And, right off, it is a meter, not a “measure.” Meters don’t measure. My preference would be to most accurately call a “powder measure” a “dispenser.” That’s what it really does. The “measure” is comparing a meter hopper volume to a weight on a scale. This may seem tediously technical, but I think it’s important to really understand what we’re doing when we use a powder meter. It’s a volume, not a weight. The volume corresponds to a weight, that we arrived at through adjusting the meter volume.

Here’s a Culver. All Culver mechanisms are the same in that they have the same values; there can be differences from model to model in the steps between whole rotations, but each whole rotation is the same. It’s like comparing a ½-moa back sight to a ¼-moa back sight. Here’s a Culver. All Culver mechanisms are the same in that they have the same values; there can be differences from model to model in the steps between whole rotations, but each whole rotation is the same. It’s like comparing a ½-moa back sight to a ¼-moa back sight.

If you plan on relying on a meter to throw charges, and not weigh each one, you best get a good meter. If the meter is only a starting point, where you are then going to use a powder trickler to top off a scale-weighed charge, meter quality is of no real concern. A powder trickler is a device that delivers propellant a kernel at a time.

So what’s a “good” meter? Good question. The very best have Culver dispensing mechanisms. Named for Benchrest pioneer Homer Culver, these precision-made mechanisms click, just like a back sight. Each click, of course, either expands or contracts a void that the propellant fills. The only Culver-equipped meters I know of are produced by smaller shops, and they are more costly. But unlike most of the major-player meter designs, a Culver setting cannot change. There are no set-screws or rotating micrometer stems or barrels. A lot of folks give advice to “check the meter each 10 throws….” Meaning, check to see if it’s still throwing the desired weight (by the way, that would be a pretty bad meter). My experience, which has come from a whopping lot of testing, showed me that my scale was going to change before a Culver would change.

The author is adamant about following this process to set a meter: Don’t throw and weigh single charges to adjust the meter. Throw and weigh 10-charge portions, with the scale set, of course, to 10-times the desired single-charge weight. The author does not recollect one time when the meter adjustment did not change following this process from what he first arrived at weighing single throws. Here’s how he sets it to adjust for a 24.0-grain throw. The author is adamant about following this process to set a meter: Don’t throw and weigh single charges to adjust the meter. Throw and weigh 10-charge portions, with the scale set, of course, to 10-times the desired single-charge weight. The author does not recollect one time when the meter adjustment did not change following this process from what he first arrived at weighing single throws. Here’s how he sets it to adjust for a 24.0-grain throw.

If you look at how a meter works, there’s a volume-adjustable cavity that rotates in position under the propellant supply, fills with propellant, and then rotates back, to dispense the propellant through an outlet. When it rotates, the granules contained in the meter are struck off, fixing and sealing the amount of propellant in the “hopper,” I call it.

A few things: One is that the smaller the granules, the more precise each fill can be. Longer-grained kernels have more air space and “stack” more than smaller-grained kernels. It’s also clear that the higher degree of precision on the internal sliding surfaces, the more “clean” the strike-off will be. It’s also clear that meter operation has a lot to do with the consistency of filling the hopper. Just like tapping a case bottom settles the propellant to a lower fill volume, same thing happens when filling the hopper in a meter.

Not too heavy, not too light. Work the handle the same each time, and have it come to a positive stop. “Thunk. Thunk.” Focus on a consistent speed. This has a huge effect on how consistent the throws will be. Not too heavy, not too light. Work the handle the same each time, and have it come to a positive stop. “Thunk. Thunk.” Focus on a consistent speed. This has a huge effect on how consistent the throws will be.

A key to good throws is working the meter handle consistently, and also settling on a contact force when the meter handle comes to a stop in the “fill” direction. It should bump but not bang. I wish I could be more clear on that, but it’s a feel that must be developed. Don’t go too slowly and gingerly take the handle to its stop, and don’t slam it there either. You want a positive, audible “thunk” when the handle stops. If it’s the same each time, fill consistency will improve. I have found that focusing on operating the handle at a constant rate of speed teaches this. It’s a positive movement that, for me, takes about one second to lift the handle.

The author recommends longer drop tubes, whether it’s for a meter or a funnel. The longer tube has the same effect as tapping the case to settle the propellant. This helps when loading stick propellant into small cases, like .223 Rem. A dryer sheet rubber-banded around the propellant container eliminates static influence, which indeed can be an influence, especially in the Western regions. And do not leave propellant in a meter! Return it to a sealed container when you’re done for the day. This setup is a Harrell’s Classic with a Sinclair stand. The author recommends longer drop tubes, whether it’s for a meter or a funnel. The longer tube has the same effect as tapping the case to settle the propellant. This helps when loading stick propellant into small cases, like .223 Rem. A dryer sheet rubber-banded around the propellant container eliminates static influence, which indeed can be an influence, especially in the Western regions. And do not leave propellant in a meter! Return it to a sealed container when you’re done for the day. This setup is a Harrell’s Classic with a Sinclair stand. This is a Harrell’s Premium. Its accuracy is astounding and is the author’s choice. With H4895, the “10-throw” test is within a tenth of a grain, for the whole pan-full. This is a Harrell’s Premium. Its accuracy is astounding and is the author’s choice. With H4895, the “10-throw” test is within a tenth of a grain, for the whole pan-full.

 

 

Facebooktwittergoogle_plusredditpinterestlinkedintumblrmail

Related

 

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...