uniflow measure with competition micrometer adjust

[chop house]

am i just stupid lucky today or am i missing some relevant information. months back i bought a used uniflow with the micro adjuster already installed but it sat unused until hours ago. i have used a uniflow for years, but never owned the adjuster version.

so, first powder ever in the hopper for me was h335. i threw a charge and paid no attention to the reading on the micrometer. i was looking for 28.0 and found that charge at a micro setting of 280. next step to 29.0 was 292. 30.0 was 301. This cannot possibly be by design? did the previous owner somehow 'zero' the micrometer in this range, with the same or similar powder?

what gives?

 

[dstoenner]

Sorry to burst your bubble. No there is no calibration. It is just a coincidence that the density of this powder just aligns. The next powder you use could be radically different. The micrometer is just nice to be able to return to a setting and be close.

David

 

[Daddymac]

It is a convenient tool to record a setting and get you close with the same powder next time, but as David stated not calibrated to weight.

 

[chootem]

I have a question for those who use the micrometer from RCBS. ~ how much powder is dropped per click graduation? Anyone use one with ball powder? Thanks

 

[SeabeeKen]

I have a question for those who use the micrometer from RCBS. ~ how much powder is dropped per click graduation? Anyone use one with ball powder? Thanks

This will depend on the individual powder size and density and the amount of air between kernels as already mentioned. The best you can do is record the setting for each powder you use.

 

[Lefty Trigger]

I have used the RCBS version with the micrometer for years with my handguns and have generated a huge spreadsheet of settings for it. I can pick a powder and a charge weight find the setting and dial it in and go to town dropping powder. Took me years to gather all the data using my beam scale but last year I went back over (about 1/3) of my data and updating it with my A&D FX120i digital scale, to my surprise a lot of it is spot on.

 

[RegionRat]

Just study a density chart with a few popular powders and you will see that it is a coincidence.
Some powders will have similar density and run close to your current values, but once you move to one with a different density and packing factor, that will change.

 

[Intheshop]

I'm still trying to wrap my pea brain around;

38.0g of H380 in 22-250's(50-52g) and 43.5g of IMR4350 in 243(85-90g). And there's some others.

 

[fkimble@charter.net]

Well Mr. Hodgen used 38.0 of a surplus powder in his 22-250. It worked great, so he called the powder H380. The 4350, just a number some one used that followed what ever naming convention they used.

Frank

 

[Coyotefurharvester]

My micro is not as consistent as my older "regular" uniflow. Rarely use it, hate the way the weight of the micro adjustment reverses the dispensing.