Powder measuring inconsistency


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MinnMooney
April 15, 2007, 11:54 PM
I use an RCBS UniFlow and Lee scoops but it seems that the cylndical powders (Varget,H335) measure inconsistently. It's always within 1-2grains but for long range shooting, that just doesn't cut it. It's very tedious to measure/pour each load.
Do other measuring tools work better or the same?

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snuffy
April 16, 2007, 12:48 AM
????? Varget is an extruded powder, H-335 is a ball powder. If you're having problems with a ball powder not measuring from a uniflow, there's something very wrong with either the measure or your operation of it.

My Hornady measure throws dead nuts with H-335, it'll throw +- 0.1 with varget also.

BsChoy
April 16, 2007, 06:38 AM
I got rid of my uniflow 3 months after I got it cuz it was so inconsistent.

steve4102
April 16, 2007, 08:33 AM
Something ain't right here! As stated above, Varget is a fine extruded powder and H335 is a ball type powder. Both should meter very well in your RCBS unit. Are you sure you mean 1 to 2 grains??? Or do you mean .1 to .2 grains? My RCBS powder measure works great with these two powders, always less than .1 variation.

eliphalet
April 16, 2007, 05:19 PM
1 or 2 grains could even be dangerous in a heavy handgun load. Surely you meant .1 or .2.
I use a Lee Perfect Powder measure it has loaded thousands of rounds using many different powders including cylinder types and has never been more than .1 grains off that I can remember. I will check every dozen rounds or so if close to Maximum.

JollyWhiteGiant
April 16, 2007, 11:50 PM
Had the same troubles with small ammounts of H335. switched over to a small powder meater and it fixed the problem.

Gnarkill
April 20, 2007, 08:57 PM
In the manual it says to run 1-1.5lbs of powder through it to coat the parts. I did that when I got my equip and it works great for me. Crank your powder drop up to like 1 million grains and run a 1 lb jug of powder through a few times. Maybe that will help. If it doesn't call RCBS, they are the bad-asses of custom service. 1800-533-5000.

redneck2
April 20, 2007, 09:15 PM
You gotta mean .1-.2. If you can't hold to 2 grains, you need to take up knitting.

As above, run a lot of pulls thru the measure. At first, they're way off, but the more you use it, the better it works. Stick powders typically have a graphite coating that lubes the works of the measure. The other thing to look for is static.

.1 pretty much doesn't mean diddly in the real world. There are measures that do a little better, but be prepared to pony up big bucks for a little extra precision.

Do yourself a favor and buy a $5 RCBS powder trickler. Drop to within .2, then trickle the rest if being within .1 is a big deal. I use the a"crap" Dillon measure on my 550 and it typically throws Varget to +/- .1, maybe .2

RecoilRob
April 21, 2007, 02:32 PM
As others have said, the measure should be throwing the H-335 to +/-.1grain. Wondering if the inconsistancy is in the scale and not the powder measure?

I have a RCBS electronic scale that wanders a bit and cannot be used for powder trickling. It is great for weighing batches of cases and such, but for powder I use the old 10-10 beam scale.

rbernie
April 21, 2007, 02:40 PM
Are y'all using a knocker of some kind before throwing the charge? My Lee Precision was more inconsistent than I liked until I started using a screwdriver held by the shank to administer a single RAP to the base of the handle assembly while the power cylinder is exposed to the powder hopper (handle is down). That settles the powder properly in the metering chamber, and my charge weights have increased in uniformity quite dramatically.

DaveInFloweryBranchGA
April 21, 2007, 03:54 PM
MinnMooney,

To help ya out, we need a bit more information. Some questions:

1. Which rotor are you using, rifle or pistol?

2. How much powder are you trying to meter or what's the charge?

3. Did you clean the measure before you started using it?

4. Did you run some graphite powder through the measure before using it?

Regards,

Dave

brickeyee
April 22, 2007, 02:37 PM
Are you using a powder baffle?
A baffle takes the weight of the powder in the hopper off the metering chamber as it fills and greatly improves consistency.
A consistent technique is also required.
Bumping the handle of the uniflow at top and bottom of each throw helps everything settle in a consistent manner, and is easier than trying NOT to bump at all.

Picknlittle
April 22, 2007, 03:42 PM
I'm using a thirty year old Uniflow. It is near dead on every stroke with IMR 4320, 4064, and BL-C(2) powders.

Something screwy somewhere with man or machine.

R.W.Dale
April 22, 2007, 04:08 PM
I have no problem throwing varget to within 0.1 to 0.2 of a grain using my older uniflow without the baffle equipped with a micrometer charge meter. Sounds like a scale issue to me.

Sunray
April 22, 2007, 05:42 PM
"...for long range shooting..." You want to weigh every load if you want consistent target accuracy. Use the scoops to get close with your scale then finish with a trickler. They can and, as you've seen, do vary plus or minus a full grain.

xsquidgator
May 7, 2007, 10:20 AM
Are y'all using a knocker of some kind before throwing the charge? My Lee Precision was more inconsistent than I liked until I started using a screwdriver held by the shank to administer a single RAP to the base of the handle assembly while the power cylinder is exposed to the powder hopper (handle is down). That settles the powder properly in the metering chamber, and my charge weights have increased in uniformity quite dramatically.


Doing this and running a pound of Unique through my Lee "Perfect Powder" measure seems to have fixed the problems I was having - in fact I did a search here on the issue and found this thread. Thanks for all of the info.

Just following the instructions on the powder measure, I was getting say + and - of up to 0.4 grain variations of Unique (shooting for 4.4 gr and getting 4.2-4.6 grains, with occasional 4.0 and 4.8 outliers in there too. Rapping the side of the powder measuring device with a screwdriver handle really helped. After reading your post I tried it and got 4.4-4.6 grain runs entirely. Much more like what I was expecting - thanks for the tip!

lee n. field
May 7, 2007, 11:38 AM
It's very tedious to measure/pour each load.

Hey, I'll give you $20 for the Uniflow. :p

Get a powder trickler, and set the Uniflow slightly low. Measure into your scale tray and work your way up with the trickler.

30Cal
May 7, 2007, 12:49 PM
.1 pretty much doesn't mean diddly in the real world. There are measures that do a little better, but be prepared to pony up big bucks for a little extra precision.

I'd argue that 0.3grs doesn't mean diddly in the real world. I've yet to see a target that proves otherwise.

Ty

Idano
May 7, 2007, 01:22 PM
It is all relative depending on the load and the burn rate of the powder. When you are loading near the floor or the ceiling for pistol a .3 grain can have catastrophic effects not to mention a huge effect on accuracy when you consider 0.3 grains is usually 10% of most nominal pistol loads. However, if you're loading for large rifle with a 50 grains charge I doubt 0.3 grains will even be noticeable at 100 yards and below especially if you worked up your load properly.

I personally prefer to stay at or below +/-0.2 grains of deviation for all my reloading and one of the reasons I don't use extruded powders when I load progressively. I leave the extruded powders to my single stage and set my powder measure on the load side and then trickle to charge weight. I also always work my loads up in the vicinity where they could safely withstand a a two sigma deviation should the powder measure have an issue. Also I make sure that my powder charge fills at least 60% of the case so I can easily see the powder in the case when I set the bullet and that a double charge is impossible.

BigSoundRacing
May 7, 2007, 04:47 PM
This weekend I took apart my new Hornady Case Activated Powder Drop for a good cleaning. It is newer, I thought I did a good job but found a huge swing in the charge last time I loaded .308. After stripping I found that oils had collected between the rifle micrometer end and the cylinder, creating lots of opportunity for the charge to varry.

Decided to polish every surface with 600 and 1000 grit sand paper guaranteed no oils now. Sat down and started using the powder drop with the scale. Went through 200 charges all measuring within a tenth, very pleased now.

Be safe, BSR

Khornet
May 7, 2007, 05:35 PM
that comsistent VOLUME is more important than consistent WEIGHT. I'd load a bunch up and test it at the range and/or chrono i before getting too concerned.

Idano
May 7, 2007, 06:01 PM
Khornet,

I have heard that too but I really wonder if it is valid. They say that the weight can change with the humidity in the air but then you would think the volume would change too with the humidity so I really question whether volume is really any more accurate. I certainly would like to know how they come to the conclusion that volume is more accurate.

Zippy06
May 7, 2007, 06:57 PM
It's the powder. Not the equipment.
You can buy 2 cans. And they will be different.
Or the shape of the powder.

brickeyee
May 7, 2007, 09:11 PM
"...you would think the volume would change too with the humidity..."

Why?

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