Powder measuring inconsistency

Status
Not open for further replies.
M

MinnMooney

Member
Joined
Mar 9, 2007
Messages
1,608
Location
east-central Minnesota
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?
 
????? 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.
 
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.
 
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.
 
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.
 
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
 
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.
 
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.
 
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
 
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.
 
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.
 
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.
 
"...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.
 
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.
Click to expand...

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!
 
It's very tedious to measure/pour each load.
Click to expand...

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.
 
.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.
Click to expand...

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
 
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.
 
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
 
Benchresters say

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.
 
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.
 
It's the powder. Not the equipment.
You can buy 2 cans. And they will be different.
Or the shape of the powder.
 
Status
Not open for further replies.

Similar threads

M
  • Locked
Powder measuring inaccuracy - Cure?
Replies
4
Views
402
Shoney
S
Craig28
  • Locked
Powder measure reccomendations?
2
Replies
42
Views
4K
RealGun
RealGun
D
  • Locked
mix different lots of same powder
Replies
5
Views
534
DubDubU
D
Hondo 60
  • Locked
Unique Woes
2 3
Replies
50
Views
3K
Miata Mike
M
K
  • Locked
Looking for new powder measure
Replies
17
Views
787
RustyFN
R
Back
Top