Translating cubic centimeters to grains

[PoorRichRichard]

How do the following measurements of cubic centimeters translate into grains? Or could someone send me to a link for a caultulator that could do this?

095, 100, 105, 110, 116, 122, 128, 134, 141, 148, 155, 163, 171, 180, 189 and 198.

Thank you
-rich

 

[Jimro]

Cubic centimeters are a measure of volume.

Grains are a measure of weight.

They don't translate unless you have a specific weight to volume figure for the substance in question. Normally black powder shooters worry about this, good article on it in the last Handloader magazine.

Jimro

 

[PoorRichRichard]

Thank you. I think I'm missing something. I'm looking into buying this shotshell reloder from Lee:

http://www.midwayusa.com/product/43...-gauge-2-3-4-3?cm_cat=Cart&cm_pla=ProductDesc

In the product description it reads:

Powder Bushings Included: Yes
Included bushing measure 095, 100, 105, 110, 116, 122, 128, 134, 141, 148, 155, 163, 171, 180, 189 and 198 cubic centimeters

What does this mean in terms of how much powder each bushing will load?

 

[Jimro]

Ahah, what it means is that you'll have to experiment with the powder you are using to figure out which bushing to use. Lee usually ships a "powder grain per CC" chart with their products to help with this.

I don't trust charts, so when I set up my Lee Autodisk I threw a number of charges and recorded the data until I figured out what my powder was doing. I ended up using a double disk of .88 cc per disk for a 24.4 gr charge of 2000-MR.

Your bushing will be the same, just make sure you verify that the bushing is in fact throwing the charge you want and you'll be fine.

Jimro

 

[mrawesome22]

198cc of powder

Good luck with that.

Sent from Android CyanogenMod 7.2

 

[Jimro]

Someone forgot the decimal... 198 cc's of anything is close to a soda can size charge. Good for 30 mm I'm sure.

Jimro

 

[PoorRichRichard]

Jimro- Thanx man Now I know I need to get a digi grain scale. Was planning on getting one soon anyway.

 

[dickttx]

Go to this link and look at the chart on page 2.

http://leeprecision.com/cgi-data/instruct/AD3398.pdf

Lee gives what they call the VMD of each powder. That figure multiplied by the number of grains you want to dispense will give you the disk hole to use. This is only a starting point and actual weight is usually lower than stated.

 

[PA-Joe]

As noted you have to use the table lee provides. The lee table generally will drop short or light charges. The table is based upon only one batch of powder. The actual density does varry by batches so each time you get a new can of powder you have to reconfirm the tables. So get yourself a good scale!

 

[Cascade1911]

The actual density does vary by batches so each time you get a new can of powder you have to reconfirm the tables.

Interesting that. So, batch to batch the density changes. What else changes? Is density or volume more important?

 

[PawPaw]

Interesting that. So, batch to batch the density changes. What else changes? Is density or volume more important?

They're both important, but as long as you don't get close to maximum charges, you should be okay.

Powder changes from lot to lot, and sometimes those changes become cumulative over time. Several years ago we all had to re-figure our IMR 3031 charges because some of us were getting close to max and a reformulation put us over max. I had to reduce my top .30-30 loads by a full grain with new 3031.

Still, there are lots of cartridges reloaded every year with volume measures. I'd hazard a guess that the vast majority of .45 ACP, .38 special, and 9mm are loaded volumetrically. Check your measure with a good scale and don't try to push the envelope.