WST inconsistent between loading sessions

[gregj]

I've noticed lately that in between evening reloading sessions, I have to re-adjust the powder drop meter significantly to achieve the desired drop of WST. For my 45ACP loads, I normally use 4.8gr for 200gr SWC bullets. The die is a Hornady LNL with a Powder Funnel powder through expander. I've polished the inside of the Powder Funnel to minimize any powder hangups, and I have a baffle in the hopper. I'm using the pistol rotor and meter.

Everything appears to be clean with no internal bridging of powder. The other night I loaded a batch of MB LSWC and last night when I checked the powder drop before loading another batch, I had to really screw in the meter as it was dropping about 5.1 gr. I checked the drop on my RCBS Loadmaster 1500 digital scale, and I double-checked it against my RCBS 505 beam scale, both indicated same weight.

I normally use W231 for plated and jacketed bullets, and have never noticed this much of an adjustment needed between sessions. The loading bench is in the basement, which is pretty constant in temp and humidity.

It almost seems like the volume of the rotor changes (metal expanding-contracting), or the powder is changing. I keep the powder in the original container tightly sealed between loading sessions. I dont leave any powder in the hopper.

Is this normal for WST? Suggestions to check?

 

[Missionary]

Good morning
Possibly your powder is settling in the hopper overnight and packing down slowly squeezing out the air. Vibrations transmitted through the ground may seen imperceptable but it is still there slowly having it´s results.
Mike in Peru

 

[RustyFN]

Is this normal for WST?

Not in my experience. After every reloading session I dump the powder back into the bottle. I'm wondering if you are leaving the powder in the hopper and it's picking up moisture from the humidity.

 

[jelenko]

I can confirm that my powder [2460] does compact after not loading for several hours.
The setting is 23.5, but, after several hours it always starts at 23.7.
After 1-2 trial/clearing charges, it goes back to 23.5.
FWIW, my set up is a Dillon powder measure on a RL 550B.

 

[gregj]

Like I said in my original post, all powder gets stored back into it's original container, tightly sealed. No powder gets left in the hopper over night.

The difference I'm seeing is not after it sits for a few hours. This is at the beginning of a new loading session, the drop is significantly higher than the night before.

When starting a new loading session, I always run several charges through the drop, sometimes 20-30, to ensure it's stabilized. .1 gr +- .1 is one thing, but not almost 1gr difference !!

 

[Walkalong]

Always run at least ten charges through the measure before weighing charges. If you are using a micrometer insert and are dialing back to a charge, be sure to run those 10+ charges through. There can be a significant difference with some powders after they settle.

WST has been very consistent for me using my 10X measure. It is a powder that meters very well. There are some real fine powders that meter better, but many more powders that meter much worse.

Run several charges through each time. Be consistent with your stroke.

Since you are doing these things, look towards your scale for the problem.

 

[higgite]

Weigh a dime at the end of a loading session and reweigh the same dime again at the next session. That should tell you if your scale is consistent or not.

 

[gregj]

I'll try that. I did check the weight of the drop (after I had to screw the insert in quite a bit to get the desired drop) with both my RCBS Chargemaster 1500 and RCBS 505 beam scale. They both weighed the same.

 

[brickeyee]

Put the powder back in the can.

The solvents are evaporating and it is changing its moisture content based on the humidity it is exposed to.

 

[gregj]

Put the powder back in the can.

I do, back in the original container, sealed tight.

 

[Walkalong]

The solvents are evaporating and it is changing its moisture content based on the humidity it is exposed to.

Not a factor.

Make sure the scale is level each time. I keep mine in the same spot all the time.

 

[higgite]

I don't have a clue what's causing it, but I do have a couple of questions. Is it always heavier than the night before? Lighter? Back and forth? Is it consistent all during each session after you readjust the powder measure? Has anything else in your loading area changed recently, for example, something that might be causing a draft or vibrating your loading bench?

 

[Red Cent]

Go get a fish tank aerator. $12-15.00. Strap/tape it to the powder drop and plug it in. Vibrator.

I have used them for years with great success. First my Lee Pro 1000s and now my 650 Dillons.

 

[Cherokee]

Since you put it back in the jar and then refilled the hopper, I see no reason for your experience other than the powder settled differently the next round. But you throw over 10 charges to settle it, that should do it. I use a lot of WST and have found it to be very reliable, I have never had that experience with it, even after several hours in the measures. I use an RCBS measure for manual loads and Dillon for my 650 loading.

 

[Blue68f100]

Have you removed your piston and cylinder (powder dispenser) and cleaned it? A little oil or moisture can cause powder to stick. You said you use PTX die, is it clean as well as the long drop tube? Is the drop tube on the dispenser tight?

I use WST and never had the problem you describe.

 

[brickeyee]

The solvents are evaporating and it is changing its moisture content based on the humidity it is exposed to.

Not a factor.

Better check the mot recent issue of Precision Shooting.

It is a factor, and has even been quantified and measures.

 

[Miata Mike]

In my experience, I have not noticed this in my WST. Fantastic .45acp powder for me by the way!

 

[Walkalong]

Better check the mot recent issue of Precision Shooting.

It is a factor, and has even been quantified and measures.

Not a factor in this instance. I'll bet the house.

There is no way his WST "absorbed" enough moisture to go from 4.8 Grs to 5.1 Grs using the same setting.

I have shot Benchrest in low humidity, high humidity, and rain, all the while loading at the range. TAC, which can shoot some great groups in 6PPC by the way, hates humidity. N133 barely notices it.

 

[gregj]

Thanks for all the input guys. Either it was a fluke, or I had something goofed up on the powder drop (odds are the later ), because I have not had the same issue again. If it happens again, I will report back, but so far, things look stable.

 

[brickeyee]

There is no way his WST "absorbed" enough moisture to go from 4.8 Grs to 5.1 Grs using the same setting.

That would depend on the relative humidity.

ALL powders absorb and release water vapor to reach equilibrium with their environment.

A closed container creates a more stable environment.

Powder not in an open container has 24 hours a day to come to equilibrium.

 

[Walkalong]

Unless it was raining while he moved it from the measure to the can and back, I can't see it.

 

[gregj]

Ok guys, I'm beginning to think WST and me just aint gonna get along. I had someone on another forum recommend against using the Honady One Shot cleaner and lube, so last night I took my powder drop completely apart and cleaned it good with carb and choke cleaner (no brake cleaner on hand, will get some this weekend), keeping it away from any rubber parts. There really was no goop inside, but there was a little build up on the rotor near the cavity. I put it together and ran another two batches (100 rnds each batch), and I still had some inconsistency between batches.

I adjust the insert for 4.8gr (checking about 20 drops for consistency), and then run a batch of 100 rounds. After I finish checking each round of the batch with the Wilson cartridge gauge, I drop a single charge and weigh it, and it's 5.0 to 5.1 gr !!! I drop a few more and it's back down to 4.8 It's like the powder is getting compressed into the rotor cavity during the time it takes to check a batch with the gauge.

I thought maybe it was the Powder Funnel, as the inside diameter is smaller than the Hornady pistol adapter, but I got similar results with it.

I do have a baffle in the hopper (Uncle Nick's baffle template). I'll try placing it at the very bottom of the hopper and see if that has an impact. Right now it's about 2" up from the bottom of the plastic hopper, but I can't see that small amount of powder creating enough pressure to cause this.

What I'm afraid of happening is if I'm called away in the middle of a batch (if you have a wife and kids, it WILL happen), and when I return the next round will have a charge higher than what it's supposed to have.

I'm at a loss.

 

[Blue68f100]

After you cleaned it did you run some graphite through it to lube it? If not it will take some time to get every thing coated.

Are you having any static problems in the hopper? Drier sheets are your best friend here.

When ever I fill the hopper I take something and tap the side till it quits settling down. Then I do my adjustments, other wise it will not stabilize. The first 10-20 I just dump out.

With the baffle make sure your openings are to the side or you defeat the purpose. 2" above the base is where mine is set at.

Is the swing arm on the powder dispenser doing a full stroke?

Make sure the down tube is tight to the body. Mine kept loosening up with use changing the stroke. I use a drop of loctite on mine, I saw no need to remove it.

When you cleaned the dispenser did you clean the body and down tube too? Run a gun patch through it to make sure it clean.

 

[gregj]

Blue, great points! Thanks. Responses below:

After you cleaned it did you run some graphite through it to lube it? If not it will take some time to get every thing coated.

No, I didnt this time. I normally do, but when I cleaned it out there was graphic powder gunked up in places it shouldnt be - and would have no effect on the powder drop, like around the threads of the adjusting stem.

Are you having any static problems in the hopper? Drier sheets are your best friend here.

None that I can tell. I keep the hopper full, and dont let it get below half before refilling, so this shouldnt be an issue. Or would it?

When ever I fill the hopper I take something and tap the side till it quits settling down. Then I do my adjustments, other wise it will not stabilize. The first 10-20 I just dump out.

After filling the hopper, I move the stem up by hand, manually dropping 10-20 charges before locking it into the press. I will then run another 10-20 cases it through it. I may tap it a little, but I have not conciously or consistently done it. I have read some folks use a mechanical means of vibrating the hopper (fish air pump, etc). I may try this and see what happens.

With the baffle make sure your openings are to the side or you defeat the purpose. 2" above the base is where mine is set at.

They are. The ridge of the baffle is perpendicular to the axis of the rotor, so the openings of the baffle are in line with the rotor.

Is the swing arm on the powder dispenser doing a full stroke?

Yes.

Make sure the down tube is tight to the body. Mine kept loosening up with use changing the stroke. I use a drop of loctite on mine, I saw no need to remove it.

This is a great point, and one I have noticed in the past. I will try the loctite tonight.

When you cleaned the dispenser did you clean the body and down tube too? Run a gun patch through it to make sure it clean.

Yes. I ran patches of paper towel wetted with the carb cleaner. I blew everthing out afterwards with canned air.

 

[Blue68f100]

They are. The ridge of the baffle is perpendicular to the axis of the rotor, so the openings of the baffle are in line with the rotor.

This is not correct it defeats the purpose of the baffle. In order for it to work the openings should not be over the pickup, should be to the side. If in alignment your piston will see the full hopper height, this is why to have it to the side.

I had a friend that was getting scattered readings and what I found is that he changed to the pistol piston but not the cylinder. Double check to make sure you have the 5/16" dia cylinder in place and not the 3/4" rifle.