Lee powder disk question regarding IMR 8208

[orientalexpress]

I picked up some IMR 8208 to load some .223 75gr a-max. I don't really reload a lot except for some 300 blackout. The only real reason I'm reloading is because of the ammo crunch as I have plenty of access to components to get me through until ammo isn't scarce. Anyways Im using lee powder disk measurer and it doesn't list IMR 8208 on the chart that tells you gr/disk. The only info I can find on Lees website is a chart that says VMD and next to IMR 8208 .07104. I'm sure theres a formula to figure it out but I can't figure it out. Can anyone help explain? Edited January 23, 2013 by orientalexpress

[mikegideon]

I assume you're using double disks. The formulas are in the instructions. I just adjust my weights with a scale. Start with a close guess and adjust. Even the listed powders aren't always 100% right with the chart.

[orientalexpress]

I just want to get close. I only have the single disk and want to do as few disk changes as possible because the screws that hold the hopper on seem pretty week. Maybe one day I'll invest in something better if I really get into it or until this setup breaks.

[mikegideon]

I just want to get close. I only have the single disk and want to do as few disk changes as possible because the screws that hold the hopper on seem pretty week. Maybe one day I'll invest in something better if I really get into it or until this setup breaks.

 

Yeah. The plain autodisk is kinda cheesey. I have two of the pro units, and one plain autodisk. You should consider the upgrade kit. The pro is a lot better unit. I had to go with the double disk when I started loading .223. That's why i wound up with two. I keep one set up for my pistol loads, and the other for rifle. Here's the kit...

 

http://leeprecision.com/pro-auto-disk-update-kit.html

[Westwindmike]

Don't unscrew the hopper! That just wears out the screw holes. I had to "fix" my hopper by JB Welding a screw in both holes. They go down through the metal base and use a nut to hold it on. To change discs, just unhook the spring and slide the disc out the front of the unit.

[mikegideon]

Don't unscrew the hopper! That just wears out the screw holes. I had to "fix" my hopper by JB Welding a screw in both holes. They go down through the metal base and use a nut to hold it on. To change discs, just unhook the spring and slide the disc out the front of the unit.

 

...or use the Pro, which has thumb screws.

[Jonnin]

about that lee disk system:

 

First, and MOST IMPORTANT:  the data that comes with it is a complete work of fiction.   The weights listed for the given powders in the given holes are usually flat out wrong.

 

Second, and key to getting anything done:  they disks are linear --- that is, its easy to figure it out.

 

So, the aggravating but simple way to deal with it is:

 

1) put in a large disk.  Assemble it all and throw a charge of powder into a case.  Weigh the charge.  Do this 10 times, take an average.

2) compute the desired grains.    So... say you wanted  10 grains.   Your randomly selected disk is "Disk .62" and it throws 8 grains.   Its proportional...

 

disk ?? = 10 grains and disk .62 = 8 grains..

so  ??/10 = .62/8

therefore you need disk that is closest to .775 

I dont have the actual disk sizes and all on hand, its just and example. 

 

While this works, you absolutely MUST weigh the charge thrown when you put it together with your computed disk.   It should be very close to your desired value.

 

It is also addative.   So if you need .775 but the disks you have are .5 and .25 using the double disk, those add to .75 for example which is "close to optimal".  So you stack those 2 disks together, for example.  

 

Let me know if that does not make sense. 

 

 

Also, you can throw a charge twice instead of double disking for most rifles.   The biggest disk is a fine charge for my 223 but anything bigger than 223 I have to hit it twice.    If you cannot concentrate enough to do this, DON'T.   I only make a few rounds of bigger stuff here and there and in small batches, so I find that I can do it safely by concentrating on the task at hand fully.  If you go this route be very, very careful not to triple up.

Edited January 23, 2013 by Jonnin

[orientalexpress]

Thanks. I was trying to read that and comprehend but I'm exhausted and I'll have to check it out tomorrow.

[orientalexpress]

Ok I went back and reread your post. The largest hole in the largest disk (I can't remember but it's something like 1.56) throws about 20gr of powder. I am not using any double disks or anything just the disks that came with the press. I loaded up 10 rounds and they cycle lock
Back. Now from what I've been reading a lot of people are getting somewhere around 23ish gr of powder. So I if I wanted to throw 2 powder charges I should start at the .80-.90 disk and weigh to get up to .21-.23 gr? Bc hypothetically a disk around .78 thrown twice would give me close to the same amount of powder as the 1.56 I'm using?

[Jonnin]

yes its all the same thing.

 

if 1.56 = 20

and x = 23

 

then x = (1.56 * 23)/20 =  1.79

 

1.79 / 2 =  .89

so yes 2 hits of .90 disk will be roughly 23 grains. 

 

and from there you can use what you now know.

we know 1.6 is roughly 20 and 1.8 is roughly 23 so

1.7 (or 2 hits of .85) is 21.5 grains. and so on.  That is what I meant when I said it is linear.

 

But its easy to make a mistake doing these ---- always, always weigh the charge.  Hopefully this stuff saves time so you can measure once, hit the calculator, and pick the correct disk hole, only needing to set up your system twice at the most. 

Edited January 25, 2013 by Jonnin

[Dolomite_supafly]

No need to unscrew or unhook the spring. Move the disk forward until the arm lets it go then you can just slide the disk out the back. I figured that out on accident. Make sure to turn your powder off and cycle it a few times first.

 

You really need a scale to measure the powder charges.

 

If your loads are already locking back on an empty there is no need to go hotter as long as the load is accurate. My most accurate load is the minimum charge or minimum plus .2 grains.

 

Dolomite

[Jonnin]

I second that.  If it locks open, its good enough probably, AND hitting each case twice is that much slower to reload and a bit aggravating. 

 

I can't turn my powder off, mine is defective, so I take the whole thing off the press, dump it back into the powder jug, put the lid on and shake it good, dump again, and then I can get the disk out.  And my spring broke so I have a rubber band on it.  I think I need a new one soon lol.