Ohaus duo measure : I am in such pain

[milprileb]

I have a new in box Ohaus Duo Measure from my late fathers reloading gear.
The plastic powder reservoir is missing. I tried using a water bottle and it works
as a replacement but I can't get powder to flow reliably, It drops charges all over
the place: be it pistol or rifle powders.

I am convinced its this reservoir but I don't know what I can do . Any suggestions?

[oneokie]

Try washing the bottle with soapy water and letting it air dry.

[milprileb]

Thanks for suggestion. I did that 4 yrs ago and it has zero effect


I should say this though, for a few yrs I thought this powder measure was okay
using this water bottle replacement but a few months ago, I decided to use my digitial
scale to check out powder charges tossed with this measure. I was seeing odd flyers
at times at the range and this repeated itself so many times, I began to wonder.

Well, a 40 charge test with the Duo Measure solved the mystery. I could have a run of
six charge very near .01 grain difference and then run into a series of charges that were as
much as .06 gr difference. It also changed dynamically as the powder levels changed.

No wonder I had flyers !!!

[1845greyhounds]

0.06 grain range? I wish my tricked-out RCBS BR3 measure performed as well. In general, you won't notice any difference +/- a few tenths unless your charge weigh is less than 6ish grains or you are using an extremely fast burning powder. I'd look for the flyer root cause elsewhere or check your decimal point.

[Le Loup Solitaire]

I have 2 Duo's that are original and they have worked consistently well. The reservoirs have an adjustable baffle system in them and I would guess that this may be the root of the problem that you are experiencing. You might try to fashion a baffle out of a piece of aluminum such as that which is used in oven cooking vessels; it is of fairly sturdy thickness. It is easy to shape and you could start by copying the one made by RCBS and see if that has any effect on solving the problem. I would also suggest changing the shape of the reservoir you are currently using as that may be a factor as well. The problem appears to be one of "flow" pressure; the duo is an accurate measure and should not do what it is doing so inhibiting/regulating that factor may be the solution. LLS

[milprileb]

1845 Sir,

If I am shooting a 43.5 gr wt. of Varget and and one charge tossed is 43.5, next is 43.9, next is 42.9 and next is 44.1 and next is 43.1.

I can't trust this measure and I am sure it would throw better powder if I had a original powder hopper on it but no one makes them anymore.

Please tell me why at 600, and 1000 yds, this ruins my day ! That 5 shots may be not so huge a spread at 100 or 200 yards but its disastrous at 300 and beyond.

[milprileb]

Solitaire : Sir, I know my father bought this measure as its a proven item for consistent powder throws. I remember him
saying so. However, I guess my only recourse is to try the baffle approach and possible see if a Lee red plastic reservoir can fit it as well.

[frnkeore]

this is my cure to your problem. note the spring around the adjusting screw, that takes the back lash out of it. this measure did the same as yours. the one in the background didn't need it and throws w/o variation with ball powers.

my 2 hopper cures are,

1. the aluminum piece fits the seat inside the measure with any transition areas having a taper so, that there is no bridging, in the top is a pressed in cap for industrial, heavy plastic 1 qt bottles. these are made of very tuff 1/16th thick plastic. here i just load different powders that are stored in this type bottle.

2. the one in the background is the same type bottle but the threads are turned to a push in fit and the bottom cut out to fill it with powder.

i hope that helps,

frank
55925

[milprileb]

Mega Awesome, will go give that a try , Many Thanks Sir

[jimkim]

Will a Forster reservoir fit it?
http://www.forsterproducts.com/client_images/catalog19938/pages/files/BR_Powder_Measure_010631-001.pdf

[milprileb]

Jim, its worth a call to Forster for outside diameter of their funnel reservoir neck to see . THanks for the idea.

[jimkim]

You're welcome. If it doesn't work maybe you can grind the threads off a MEC powder bottle, or make an adapter.

[Gunor]

I have a RCBS Duo Powder Measure - plastic hopper still good except for the crack. Like to have a replacement. Also need the thumb screw for the micrometer.

Did you try the dryer cloth trick for cling?

Problem: Please tell me why at 600, and 1000 yds, this ruins my day ! That 5 shots may be not so huge a spread at 100 or 200 yards but its disastrous at 300 and beyond.

Go buy a Lee Perfect Powder Measure for $25 or so.

Varget - trickle grain by grain to get weight.

Also look at the ballistics - how much does a 0.1 gr change in powder change the velocity - and the downrange ballistic's. Kinda of interesting.

Lee Perfect Powder Measure - I loaded a lot using that powder measure. Long Range - dump into pan and trickle the rest.

Varget - trickle grain by grain to get weight.

I used it for High Power, LR and Palma. Really fun to read all the people talking about the powder measures, culvers, and high speed...$$.

[Pressman]

Forster hoppers will not work, they have a 1/2" neck - too small. Ditto for Lee. RCBS hopper can be made to work sort of.
Ken

[vernm]

I used the Lee hopper. It has a built in powder baffle. Put a heavy bead of Permatex silicone adhesive around the angled part of the hopper and stuck it in the measure. Let it cure for a few days and it is solid. The angle on the hopper is not exactly the same as the measure. But it is close enough to work. Since the hopper is bigger in diameter than the flange on the measure, it only goes in so far and does center up the hopper. When I change powder, I always take the drum out and blow all the old powder out of the space between the hopper and the measure. No way to take the hopper off to clean out without destroying the hopper. I always wrap a dryer sheet around the hopper and hold it on with a rubber band. Leave the gap in the front so you can see the powder level and don't run dry. Not a perfect fix, but it has worked for me for several years now.

[bbqncigars]

I took an inline powder baffle meant for MEC powder bottles and ground the male thread down until it was a snug fit in the Ohaus body. I used JB Quik weld to make it permanent. Now I can still unscrew the powder bottle when I need to, and the baffle has really helped in the charge consistency. The B & M measure still gets the call for Varget and 4759 powders though.

[Sonnypie]

Jim in Flowery Branch Georgia wanted a bigger powder reservoir a while back.
I suggested this:

http://i1195.photobucket.com/albums/aa382/Sonnypie/3_powder_x.jpg

Do you suppose static is fouling the feeding?

[Janoosh]

I also use the Mec metal powder baffle. I took a file and slowly reduced the threads until the baffle was a snug fit. It works and I can use Mec powder bottles now.

[dickttx]

My hopper got crushed in a move several years ago. Since then I have used the MEC powder bottle. IIRC, I had to file down the threads on the bottle to get it to fit.

[Alan in Vermont]

Doesn't RCBS still catalog the Duo-Measure? Did they change the hopper from the original Ohaus design? If not has anyone tried getting a hopper from them?

[jimkim]

If you have access to a lathe and a piece of scrap brass(my first choice) stock, turn an adapter bushing so you can use the Forster or a Lee PPM hopper. I'd make it similar to the piece in this picture. The shoulder would give it a positive stop.
http://www.ajvs.com/images/AJVS/AJVS_Flange_Couplings_PN03415.jpg

http://leeprecision.com/hopper-cov-round-red.html

[RG1911]

If I am shooting a 43.5 gr wt. of Varget and and one charge tossed is 43.5, next is 43.9, next is 42.9 and next is 44.1 and next is 43.1.

I can't trust this measure and I am sure it would throw better powder if I had a original powder hopper on it but no one makes them anymore.

Please tell me why at 600, and 1000 yds, this ruins my day ! That 5 shots may be not so huge a spread at 100 or 200 yards but its disastrous at 300 and beyond.

Since I have found my Duo-Measure to be quite reliable, I would like to offer another possibility for the erratic charges. (Using a baffle and a different hopper sound like excellent beginnings.) I have tested that consistency of operation is very important with the Duo-Measure (as it is for my Harrell's measure, too). Make sure each sequence is the same as all others.

Measure fluctuation aside, here's an interesting re-do of the old ladder method of determining an optimum load. Optimal Charge Weight (OCW) by Jim Newberry makes for interesting reading, and has quite a few adherents in the long-range shooting fraternity:

http://optimalchargeweight.embarqspace.com/

Since I found the ladder method terminally frustrating and prone to error, I plan to try OCW when my latest precision long-range rifle is finished.

Richard

[smokeywolf]

Unless I'm misreading your post, you are getting a variation of 6/100 of a grain; close to half a tenth. Unless you're shooting in competition, in my book that's not unacceptable.

smokeywolf

[milprileb]

Unless I'm misreading your post, you are getting a variation of 6/100 of a grain; close to half a tenth. Unless you're shooting in competition, in my book that's not unacceptable.smokeywolf

We are talking Tenths . Thus, a 6 Tenths of a grain fluctuation is havoc on accuracy.

[smokeywolf]

I agree that .6 grains would play "havoc on accuracy". However, in post #3 you specify .06 grains. Ergo my belief that you were talking hundredths, not tenths.


Well, a 40 charge test with the Duo Measure solved the mystery. I could have a run of
six charge very near .01 grain difference and then run into a series of charges that were as
much as .06 gr difference. It also changed dynamically as the powder levels changed.

Not to nit pick, but when it comes to specifying powder measurements I think it's important to use accurate notations.

Sorry for the misunderstanding,

smokeywolf

[milprileb]

Yup... that .06 was meant to be .6.

Anyhow, you see my frustration with the measure.

[o6Patient]

As has been stated : you need a secondary chamber w/ a straight drop above the actual cylinder(as frnkeore showed in pics)
or you will get erratic compression and bridging especially if the taper is a radius rather than straight.
A 3/4 cu female threaded adapter works well to transition from hopper to measure.
I used a paint spray gun hopper and heated the plastic and fitting to make threads in the plastic.
The spray gun hopper has a washer type baffle in it already and I drilled it out a little bigger.
The top screws on and it came out really good.

[o6Patient]

(I didn't think a duo could throw charges 6 ths off

[o6Patient]

some pics of my ohaus duo57191571925719357194