A powder whyizzat.......

[Jack Stanley]

I was using the powder measure today and for no particular reason happened to work with some Unigue and some Universal clays . After hearing how close they are in capabilities I was curious to see what the same volume of each would weigh .

For a measure of Unique that weighs six point three grains , the same measure of Universal Clays weighs seven point three grains .

I know they are not the same powder even though they may do the similar jobs . It just seems odd that for being similar in capabilities they might just be closer in weights .

I'm not trying to figure a top load or anything here , I've been using Universal clays for a very long time now and going back to using Unique . It would be easy to just think to use a lower charge of Unique but it doesn't matter since I don't run either powder close to the top and , I'm going to have to reshoot all my loads for Unique . Being retired now should make that job a little easier huh[smilie=1:

A thank you in advance to you powder wizards .

Jack

[Rocky Raab]

Similar burn rate does not necessarily also mean similar density. You've discovered that Universal is denser than Unique.

[HammerMTB]

I was using the powder measure today and for no particular reason happened to work with some Unigue and some Universal clays . After hearing how close they are in capabilities I was curious to see what the same volume of each would weigh .

For a measure of Unique that weighs six point three grains , the same measure of Universal Clays weighs seven point three grains .

I know they are not the same powder even though they may do the similar jobs . It just seems odd that for being similar in capabilities they might just be closer in weights .

I'm not trying to figure a top load or anything here , I've been using Universal clays for a very long time now and going back to using Unique . It would be easy to just think to use a lower charge of Unique but it doesn't matter since I don't run either powder close to the top and , I'm going to have to reshoot all my loads for Unique . Being retired now should make that job a little easier huh[smilie=1:

A thank you in advance to you powder wizards .

Jack


There is a whole table of powder densitys with every Lee measure. You can calc the volume/weight of most any powder using the chart.
What you did proves you need to not make "ass"umptions. Good thinking on your part....

[Az Rick]

What fun! Discovering what load shoots good in what gun is what it's all about. I wish I had the time to do more of it. I use Unique but only in the .44spl. for now. I like it except for the fact it doesn't meter well. I'm loading for accuracy though which means to me weighing each charge, I know, kinda anal but that's what reloading does to you.
Good luck and have fun.

Best Rick

[462]

"I wish I had the time to do more of it."

Same-same, here.

[fecmech]

I'll give you a little different take. Set your powder measure to throw a charge of Bullseye and go chrono the load. Dump the BE and put 231 in the measure but don't change the setting and go chrono the load. Pretty much same same on velocity in .45's and .38's although the weights will be different( 231 being higher). Equal volumes of BE and 231 give almost identical velocities. I load on progressive presses with powder bushings that's where it shows up quickly. I don't know if this is true or not but a commercial reloader friend told me that Winchester originally spec'd 231 that way to get into the commercial market ( along with pricing it 25% less than BE in the 70's).

[Jack Stanley]

fecmech , that's a twist I hadn't thought of . I was trying to think of the answer to my own question and so far the best I can come up with is that Unique has more "fluff" to it so it weighs less for a given volume .

I used this very light load of Unique in a 30WCF case with a 311466 for giggles . I'm not sure but in this case I think the Universal Clays might be a safe load as well . I have almost a pound of the stuff left before I go back to Unique and I think I'll use it to use up all the leftover bullets I've got laying around . I'm sure I can work with the stuff , it's been pretty good to me in the '06 for gallery loads .

Jack

[XWrench3]

with only a few exceptions, you MUST treat every powder as its very own beast. or you will find yourself in very serious trouble. there are plenty of blown up guns out there to prove it. don't chance it. hospital stays are no fun for anyone!

[fecmech]

Jack--along the lines you've been thinking is the relationship between Herco and WSF. Here are two powders in the same speed range that have very different densities (WSF is much more dense) but will give almost identical velocities by weight in 9MM and 38/357.

[Jack Stanley]

To those concerned with my safety and others thank you I'm touched but please fret not . I do not intend to use these two powders interchangably . After burning over twenty pounds of Universal Clays and even more of Unique I have some idea of how it works in the few rounds I use them in and don't stray very far off the reservation . I do tend to run both types on the slow side .


Fecmech , I never knew that about Herco and WSF , of course I've never used either one . After all the Unique and Universal Clays I've used I never noticed this little quirk . When I get some time I'll need to find a Unique load for gallery use in the 03 like the Universal is doing right now . I think I have loads for about five different bullets and will have to reshoot all of them to get them to do what I want .

Jack

[geargnasher]

When you think about it, it makes sense. There are only two kinds of smokeless powder, single-base and double-base. All different kinds of ways of making them burn, but in the end it's still nitrocellulose and nitroglycerine.

Try this: Look up a mid-range load for any caliber using five different powders in three or four manuals and average the charge weight. Now, go to the Lee VMD table and find the volume of each powder that matches your average charge weight. Powders producing similar peak average pressure in a certain cartridge have an uncanny tendency to be about the same volume, plus or minus a few percent, unless comparing SB to DB.

Gear

[Tracy]

When you think about it, it makes sense. There are only two kinds of smokeless powder, single-base and double-base. All different kinds of ways of making them burn, but in the end it's still nitrocellulose and nitroglycerine.

Gear

There are also triple-base powders that add nitroguanidine to lower the flash signature. IMR-7883 is one example.

[Jack Stanley]

Thanks Gear , now at least I don't think I'm alone seeing odd stuff like that .

Jack