Load density

L

lilabner

Guest
Are cartridges with high load density more accurate? What about compressed loads? Seems like ignition would be more uniform with a full case.
 
Even though it is only one of the many factors in getting a cartridge to shoot accurately, I believe that a high load density helps any cartridge shoot to its potential. Any round can be loaded to a high density by using the appropriate powder for the bullet you are using. I dont really care for compressed loads. If you have to go that far to get up to speed, your powder is too slow. It can also cause problems when you seat the bullet. If it is compressed alot, the seating stem will leave a ring on the bullet, which may not help it to shoot very well. Hope this helps. :)
 
load density

Bindy is pretty much correct. Most cartridges perform thier best when loaded above 90% capacity. Compressed loads are very finicky critters, From incomplete powder burning to actually pushing the bullett out of the crimp if laoded to dense. Had this happen on a compressed load for a 30.06. Select a faster or slower powder that will give 90 to 95 % fill density for the case.

Good luck.
 
Most of my accurate loads are between 73-91% but notice the following example: 7.5gr red Dot.

http://www.accuratereloading.com/6mmbrr.html

Lots of cast bullet and reduced loads are very accurate without reaching 20%load density. I thing its more a dynamic between case/cartridge volume powder speed and bullet mass. Another point of interest some velocities are more accurate than others.
 
Thanks for the advice. I frequently hunt steep terrain, sometimes shooting downhill, sometimes uphill. When loading density permits the powder to shift, does it affect ignition and point of impact? Would a filler be beneficial?
 
spreadsheet

Here is a spreadsheet that some students and I made up. It estimates load density for a particular bullet/case. You'll have to change the data in black. All the colored ones will automatically change for you. You'll see down towards the bottom, I have some different powders. The spreadsheet calculates out what it takes to get to 80%-90%, etc, then if you put in your load and bullet seating depth it will estimate the load density.
Load density will change based on what powder you are using. For example, if you use 40 grains of R-19 and 40 grains of Hunter, your load density will not be the same. If you use a different powder than what I have listed, you'll have to find the density of the powder and enter that.

The spreadsheet was a good class project and it it kinda fun to figure it out, but it doesn't help you play the wind. You'll still have to experiment and find out what your barrel likes - regardless of load density.

As far as your last question, unless you keep your cases in an automatic leveling device of some sort - your cases will see a lot more shifting than when shooting uphill or downhill. I wouldn't worry about that part.

hope this helps

Stanley
 

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Most powders are position sensitive in the case, shooting downward typically causes the highest pressure variation. A filler such as Dacron polyester can be used but it can also ring the barrel chamber.

My advice try IMR SR4759 for reduce loads it is the least postion sensitive reduced load powder I've tried. Lots of available information in older Load manuals Such as one Published by LEE for most cartridges.

Others to Try IMR Trail Boss and Accurate 5744

Hodgdon Youth Loads are also published for several cartridges and H4895 is a very good powder.

http://www.go2gbo.com/forums/index.php?topic=56618.0;wap2


Here are some links to my websites and a free reloaders spreadsheet
software to play with:

http://maxpages.com/thejedilair/Firearms_Shooting


My reloaders Spreadsheet Project Free to use and modify as you choose:


http://wumingta.tripod.com/pub/id3.html
 
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