PCBS Uniflow

herbie53 · January 11, 2007, 02:04 PM

I just recently bought a Uniflow and have been getting used to throwing charges and then weighing them to make sure I'm doing it right.

I seem to vary by a 1/10th or 2/10 either way every few charges. Is this normal? Would the powder baffle inside the powder chamber make any difference.

I normally wouldn't quibble, but I was expecting a bit more consistency. This way my 4.5 of Bullseye may be 4.4, 4.6 or what have you.

Any advice?

Thanks

Bryan

Dave R · January 11, 2007, 03:14 PM

Is your Uniflow brand new? I've heard you have to throw several hundred charges through them to "break them in."

I bought mine used, and it occasionally varies by 1/10 of a grain, depending on the powder. Ball powders it doesn't even vary a tenth. Stick powders and big flakes can vary a tenth, on occasion.

Also, you have to be careful to move the throwing arm the same way each time. I believe the manual discusses that. Variations in the way you move the arm can affect the weight of the charge thrown.

herbie53 · January 11, 2007, 03:23 PM

It's a very new toy.

So I maybe have to run a bunch of powder through to break things in? Interesting. I did note that you wanted to move the handle in the same fashion each time.

Given that we're supposed to get yet another snowstorm, I might be able to have the time to do that

Bryan

bigautomatic · January 11, 2007, 03:43 PM

I made a baffle for mine (just copied the original) and it definately made a difference in charge weight consistancy. Without a baffle, the weight of the powder inside the unit decreases every time every time you throw a charge.

carl418 · January 11, 2007, 07:34 PM

Mine sometimes will throw under, then the amount that charge was under is in with the next charge; in other words, two cases with one way under and the next one way over. It's easy to catch, but I wish I didn't have to deal with it.

Would a baffle help that problem? And, how did you make it?

Sorry... not trying to steal this thread!

cheygriz · January 11, 2007, 09:24 PM

One or two tenths? I wouldn't worry about it.

drvector · January 11, 2007, 09:46 PM

Get the powder baffle… I had the same problem with my uniflow until I put the powder baffle in, it made a big difference. It's not perfect, I still measure every tenth load or so, but it is significantly better than not having one.

Dave R · January 12, 2007, 02:45 PM

One other thought...

If you have a large arbor, and you're throwing small charges for pistols, its not going to be as accurate as the small arbor.

If you don't know whether you have a large arbor...how big a charge can you throw? If you can throw a 40gr. charge, you have a large arbor. Get a small arbor for small pistol charges.

bigautomatic · January 13, 2007, 08:11 PM

Carl418,
I just went by a picture of the RCBS baffle, and used a piece of sheetmetal and tin snips. It did take some trial and error, to get it to fit in the cylinder but it doesn't have to be exact. The principal is to have the same weight of powder sitting on top of the arbor every time you throw a charge, and the baffle will help keep that weight consistent. Took me all of 15 minutes to make the baffle.

MADISON · January 15, 2007, 11:21 AM

1/10th or 2/10 either way is exceptional consistancy.
I have owned a Uni-Flo for 37 years and love it. I use an old PACIFIC/Hornady pistol powder measure and LEE disk powder measures for pistol loadings.

Edward429451 · January 15, 2007, 12:05 PM

I agree, 1 or 2 10'ths isn't enough to be concerned about unless you're loading near max in which case you'd be trickling them up to precise weight anyway.

When I get a new jug of powder, I set it and throw 10 charges to get an average, and plug the info into the chronograph math sheet, record the extreme spread, avg spread and so forth. I then scotch tape this info onto the powder jug. (I also weigh one charge where the measure is tapped / bumped to let me know what I could expect in overage if something unforseen happens.) Also record which measure the test was done on (RCBS-DILLON-etc.)

January 11, 2007, 02:04 PM	#1
herbie53 Member Join Date: October 15, 2006 Posts: 47	PCBS Uniflow I just recently bought a Uniflow and have been getting used to throwing charges and then weighing them to make sure I'm doing it right. I seem to vary by a 1/10th or 2/10 either way every few charges. Is this normal? Would the powder baffle inside the powder chamber make any difference. I normally wouldn't quibble, but I was expecting a bit more consistency. This way my 4.5 of Bullseye may be 4.4, 4.6 or what have you. Any advice? Thanks Bryan

January 11, 2007, 03:14 PM	#2
Dave R Senior Member Join Date: January 7, 2000 Location: Idaho Posts: 6,073	Is your Uniflow brand new? I've heard you have to throw several hundred charges through them to "break them in." I bought mine used, and it occasionally varies by 1/10 of a grain, depending on the powder. Ball powders it doesn't even vary a tenth. Stick powders and big flakes can vary a tenth, on occasion. Also, you have to be careful to move the throwing arm the same way each time. I believe the manual discusses that. Variations in the way you move the arm can affect the weight of the charge thrown. __________________ I am Pro-Rights (on gun issues).

January 11, 2007, 03:23 PM	#3
herbie53 Member Join Date: October 15, 2006 Posts: 47	New Uniflow It's a very new toy. So I maybe have to run a bunch of powder through to break things in? Interesting. I did note that you wanted to move the handle in the same fashion each time. Given that we're supposed to get yet another snowstorm, I might be able to have the time to do that Bryan

January 11, 2007, 07:34 PM	#5
carl418 Senior Member Join Date: February 20, 2006 Location: north Ga Posts: 208	Mine sometimes will throw under, then the amount that charge was under is in with the next charge; in other words, two cases with one way under and the next one way over. It's easy to catch, but I wish I didn't have to deal with it. Would a baffle help that problem? And, how did you make it? Sorry... not trying to steal this thread! __________________ Carl S&WCA \| SAF \| GOA Life \| NRA Benefactor

January 11, 2007, 09:24 PM	#6
cheygriz Senior Member Join Date: May 11, 2002 Location: high up in the rockies Posts: 2,289	One or two tenths? I wouldn't worry about it. __________________ If you think a mighty military force is expensive, wait 'til you see what a weak one costs.

January 11, 2007, 03:43 PM	#4
bigautomatic Senior Member Join Date: December 18, 2005 Location: Ohio Posts: 610	I made a baffle for mine (just copied the original) and it definately made a difference in charge weight consistancy. Without a baffle, the weight of the powder inside the unit decreases every time every time you throw a charge.

January 11, 2007, 09:46 PM	#7
drvector Member Join Date: March 28, 2005 Location: Northeast Posts: 69	powder baffle Get the powder baffle… I had the same problem with my uniflow until I put the powder baffle in, it made a big difference. It's not perfect, I still measure every tenth load or so, but it is significantly better than not having one. __________________ Regards kdb

January 12, 2007, 02:45 PM	#8
Dave R Senior Member Join Date: January 7, 2000 Location: Idaho Posts: 6,073	One other thought... If you have a large arbor, and you're throwing small charges for pistols, its not going to be as accurate as the small arbor. If you don't know whether you have a large arbor...how big a charge can you throw? If you can throw a 40gr. charge, you have a large arbor. Get a small arbor for small pistol charges. __________________ I am Pro-Rights (on gun issues).

January 13, 2007, 08:11 PM	#9
bigautomatic Senior Member Join Date: December 18, 2005 Location: Ohio Posts: 610	Carl418, I just went by a picture of the RCBS baffle, and used a piece of sheetmetal and tin snips. It did take some trial and error, to get it to fit in the cylinder but it doesn't have to be exact. The principal is to have the same weight of powder sitting on top of the arbor every time you throw a charge, and the baffle will help keep that weight consistent. Took me all of 15 minutes to make the baffle.

January 15, 2007, 11:21 AM	#10
MADISON Senior Member Join Date: January 1, 2000 Location: Roanoke, Virginia Posts: 2,678	RCBS Uni-Flo 1/10th or 2/10 either way is exceptional consistancy. I have owned a Uni-Flo for 37 years and love it. I use an old PACIFIC/Hornady pistol powder measure and LEE disk powder measures for pistol loadings.

January 15, 2007, 12:05 PM	#11
Edward429451 Junior member Join Date: November 12, 2000 Location: Colorado Springs, Colorado Posts: 9,494	I agree, 1 or 2 10'ths isn't enough to be concerned about unless you're loading near max in which case you'd be trickling them up to precise weight anyway. When I get a new jug of powder, I set it and throw 10 charges to get an average, and plug the info into the chronograph math sheet, record the extreme spread, avg spread and so forth. I then scotch tape this info onto the powder jug. (I also weigh one charge where the measure is tapped / bumped to let me know what I could expect in overage if something unforseen happens.) Also record which measure the test was done on (RCBS-DILLON-etc.)