RCBS Combo ??

beaverguy · March 28, 2007, 09:43 PM

I just recieved a new RCBS combo scale & powder dispenser.. After setting up and calibrating it (twice) it consistantly throws 2/10 of a grain light set at 50gr. It also throws light with different powders set on different wieghts..
Has anyone here had the same problem or do I have a bad combo??

Thanks

Edward429451 · March 29, 2007, 11:03 AM

It sounds ok to me. Different powders will throw with different consistencies depending on the shape of the powder granules. Ball powder would obviously throw the most consistent, flake would be somewhat inconsistent, and extruded powders will throw the least consistent.

When I get a new LB of powder I check it for consistency by weighing 10 charges and do the math to get the average deviation etc., and tape that slip of paper to the powder jug for easy reference. If you have multiple measures you'll want to also identify the measure used also.

What kind of powder are you using? I'm guessing a flake powder.

williamd · March 29, 2007, 11:25 AM

Yep, sounds the norm. Reweigh and tag for every powder type change.

Rimrod · March 29, 2007, 01:01 PM

I have an early RCBS combo and I don't know how much they have changed, but mine is always within .1 grains and most of the time it was exact.

I deleted part of my original post. I quoted a feature wrong because I've never used that part of it.

Anyway my combo can be used as a trickler too and is very accurate. If they've changed them to the point where they are that far off why get one? Jst set a meter low and top it off with a trickler.

williamd · March 29, 2007, 03:16 PM

Mine varies a bit from powder type to powder type. And even within powder types a bit ... never enough to affect what I am doing with the round. When a very [too] serious shooter I weighed evey load (and trimmed and turned and weighted bullets, and calipered, and filled with kapok, ..... even put the round in the chamber with the case name up all teh trime. It would drive me nuts today!).

Hey, gotta go shoot!

cheygriz · March 29, 2007, 05:16 PM

Many of the old time benchresters believe that volumetric consistency is more important than weight consistency, and therefore don't bother weighing individual charges.

I throw charges straight out of the measure, even for my most accurate varmint rifles. I load 6MM Remington for a heavy barrel varmint rifle, and they shoot 5 shots into 3/8 inch or less day after day. They are loaded on a Dillon 650, with the WW760 thrown directly from the measure.

Maybe I could get better groups than 3/8 inch, but since I don't shoot benchrest, the prairie dogs and ground squirrels never know the difference.

March 28, 2007, 09:43 PM	#1
beaverguy Member Join Date: April 7, 2006 Location: U.P. of Michigan Posts: 41	RCBS Combo ?? I just recieved a new RCBS combo scale & powder dispenser.. After setting up and calibrating it (twice) it consistantly throws 2/10 of a grain light set at 50gr. It also throws light with different powders set on different wieghts.. Has anyone here had the same problem or do I have a bad combo?? Thanks

March 29, 2007, 11:25 AM	#3
williamd Senior Member Join Date: March 13, 2007 Location: SoCal Posts: 801	Yep, sounds the norm. Reweigh and tag for every powder type change. __________________ "Outlaw guns and only outlaws will have guns!" Unfortunately, we may be moving in that direction. NRA Benefactor, Conservative!, VN '64-'65. Never sell a gun or a car ... and retire rich!

March 29, 2007, 01:01 PM	#4
Rimrod Senior Member Join Date: October 19, 2005 Location: Behind enemy lines Posts: 1,309	I have an early RCBS combo and I don't know how much they have changed, but mine is always within .1 grains and most of the time it was exact. I deleted part of my original post. I quoted a feature wrong because I've never used that part of it. Anyway my combo can be used as a trickler too and is very accurate. If they've changed them to the point where they are that far off why get one? Jst set a meter low and top it off with a trickler. Last edited by Rimrod; March 29, 2007 at 02:16 PM.

March 29, 2007, 03:16 PM	#5
williamd Senior Member Join Date: March 13, 2007 Location: SoCal Posts: 801	Mine varies a bit from powder type to powder type. And even within powder types a bit ... never enough to affect what I am doing with the round. When a very [too] serious shooter I weighed evey load (and trimmed and turned and weighted bullets, and calipered, and filled with kapok, ..... even put the round in the chamber with the case name up all teh trime. It would drive me nuts today!). Hey, gotta go shoot! __________________ "Outlaw guns and only outlaws will have guns!" Unfortunately, we may be moving in that direction. NRA Benefactor, Conservative!, VN '64-'65. Never sell a gun or a car ... and retire rich!

March 29, 2007, 05:16 PM	#6
cheygriz Senior Member Join Date: May 11, 2002 Location: high up in the rockies Posts: 2,289	Many of the old time benchresters believe that volumetric consistency is more important than weight consistency, and therefore don't bother weighing individual charges. I throw charges straight out of the measure, even for my most accurate varmint rifles. I load 6MM Remington for a heavy barrel varmint rifle, and they shoot 5 shots into 3/8 inch or less day after day. They are loaded on a Dillon 650, with the WW760 thrown directly from the measure. Maybe I could get better groups than 3/8 inch, but since I don't shoot benchrest, the prairie dogs and ground squirrels never know the difference. __________________ If you think a mighty military force is expensive, wait 'til you see what a weak one costs.

March 29, 2007, 11:03 AM	#2
Edward429451 Junior member Join Date: November 12, 2000 Location: Colorado Springs, Colorado Posts: 9,494	It sounds ok to me. Different powders will throw with different consistencies depending on the shape of the powder granules. Ball powder would obviously throw the most consistent, flake would be somewhat inconsistent, and extruded powders will throw the least consistent. When I get a new LB of powder I check it for consistency by weighing 10 charges and do the math to get the average deviation etc., and tape that slip of paper to the powder jug for easy reference. If you have multiple measures you'll want to also identify the measure used also. What kind of powder are you using? I'm guessing a flake powder.