Powder density variation

[fbody_mike]

Hi all, I'm new to reloading. But I have been reading a lot and have made and fired about 200 rounds so far. I've got a question about powder density. So I've been using 1lb IMR 4064 through a RCBS quick change powder dispenser. After getting my technique down I found I could get reliable results of 42.5 grains per swing of the lever. Well I was finishing off my first container of 4064. I refilled the hopper from a new bottle of 4064 and checked the weight out of the quick change. Now I was getting consistent drops of 45 grains. So I adjusted the volume and was back to my 42.5.

So is it common to have density variations between batches of powder from the same manufacturer?

I have heeded all I read about not mixing and returning to the original container. Is this another reason why, besides accountability and safety?

Thanks, and I have been reloading 7.7 x 58 for an Arisaka type 99.

[McGuiver]

Did you buy the bottles at the same time? Are they from the same lot?


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[Gringo Bandito]

So is it common to have density variations between batches of powder from the same manufacturer?

Yes..I have read that a 10% variation is possible.

[JagerDog]

I recently changed changed jugs of Titewad and International (18gr and 14gr respectively). There was a change of approx 1 gr on each. So yeah...density varies.

[fbody_mike]

Different vendors and different batches.

[Dnele928]

As a part of your Quality Control, you should pull out a cartridge after the powder drop and check the weight, pick a number, every 10, 20 loads. See if it's shifting. Adjust accordingly.

Also, a full hopper versus a nearly empty hopper may have variations in powder drops. It may be a good practice to keep the hopper at about half full...add small bits of powder to keep it in the half full range.

These are things you can control. Powder variations from the factory are out of your control.

[McGuiver]

Different vendors and different batches.

If you like the powder and plan on shooting it a lot, buy powder in larger quantities in the same lot. I usually purchase 1lb containers, but I have purchased 8lb container of CFE223. I just make sure they are in the same lot number.

If you get power from different lots, density can change, and your POI (Point on Impact) for a given round with the same grain weight of powder can shift. This is due to manufacturing processes. I have heard powder "power" could vary up to 10% lot to lot.

Here is a study the military did for H4831 powder.

http://www.dtic.mil/dtic/tr/fulltext/u2/a572333.pdf

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[PatC415]

OP, to be safe:
You should ALWAYS re-work you loads from the bottom up when changing powder lots.
As others have said, if you like a particular powder, 8lb'ers are the way to go.

[bazineta]

Stick powder in general is something you want to be verifying when using a thrower, as even a tiny bit of inconsistency in the stick length will make a difference, and unless your technique is flawless, you'll cut sticks from time to time when throwing anyway.

If you want to always throw, i.e., you're using a Dillon, for example, than a ball powder will usually be reasonably consistent and can be a good choice.

If you're not running a press where you must have an automatic throw, then typically you just set the thrower to be just under your desired weight and trickle up. Doesn't take much time at all if you get it dialed in, and it can be real peace of mind.

[OpenSightsOnly]

Since IMR 4064 is a long stick powder, you may want to try Varget or IMR 4320. I have used those two for 7.5 Swiss and 8mm.

If you like IMR 4064, having a Chargemaster 1500 will make the process bearable.

[fbody_mike]

Thanks for all the advice guys. I'm sure I'm cutting sticks I can feel it when it swing the lever.

I only went with 4064 because it was on the shelf at the local shop and I had a recipe.

Any recommendation on a ball powder that will work good in 7.7 58 and 30 06?

[McGuiver]

Powder density variation

Thanks for all the advice guys. I'm sure I'm cutting sticks I can feel it when it swing the lever.



I only went with 4064 because it was on the shelf at the local shop and I had a recipe.



Any recommendation on a ball powder that will work good in 7.7 58 and 30 06?

H4831 or H4831SC (short cut) will work in both of those. I use it in my 7.62x54R with heavier loads. This is a stick powder. The short cut powder measures nicely.

CFE 223 will also work in 30-06. Don't know about 7.7x58.

BL-C2 ball powder will work in both or your rounds. You may need to use Magnum or NATO primers in them.


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[Fishslayer]

Also, a full hopper versus a nearly empty hopper may have variations in powder drops. It may be a good practice to keep the hopper at about half full...add small bits of powder to keep it in the half full range.

These are things you can control. Powder variations from the factory are out of your control.

^^^ This. Powder will also "settle" in the hopper making for a heavier charge.

[Whipper1]

I was having some problems with varying weights too. I put baffle in my powder measure and that helped a lot. here is a link to the one you described.

http://www.midwayusa.com/product/111457/rcbs-quick-change-powder-measure-powder-baffle