load data terms - 100% density

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Those ARE a bit odd, aren't they! But, 100% density would mean that the powder charge fills the case to the base of the bullet when seated.

Compressed is obviously when the seating of the bullet compacts the powder into a smaller area than unconfined in the case, but the Major and Major Compressed descriptions are very unusual. I would surmise that they describe more compressed charges but it almost sounds like someone poorly translated some foreign literature.

Some reloaders cram more powder into a case than will actually fit loosly by filling and compressing then filling again before seating the bullet. Maybe they are trying (poorly) to describe such a practice?
 
can't help on major unless they are describing major power factor...?

major compression, to me, would refer to when you hear some serious crunching going on when you seat the bullet - sorta like putting 26.5 grains of varget behind a 60 grain bullet in 223... the powder comes up to the mouth, or damned close, and you still have to figure out how to get a bullet seated and held in place...
 
I've never seen the terms either. In blackpowder cartridge shooting, it's common to use a compression die when loading your cartridges. This is a solid, piston-like die which reallly compresses the old Goex down to a solid mass in the brass. You'd then seat your bullet on top of that. Okay to do that with blackpowder and the proper rifle. I would never do it with smokeless (if that's what they're referring to.)
 
Undoubtedly 100% Density means the case is full of powder up to the base of the bullet (There is a similar term, Density of Loading, used in Powley's ballistic calculations that is not the same thing.)

Compressed means the powder charge is packed down by seating the bullet. There are some rifle loads in which the powder charge fills the case to the mouth and seating the bullet compresses the powder charge down the neck. Or as Murphster says, we BPCR shooters do it with a separate die so as to not mash our soft lead-tin alloy bullets out of shape.

I don't know what they mean by Major Compression unless they have some arbitrary threshhold between normal and Major compression of the powder charge.
 
thanks for the input everyone.

are compressed charges inherently more dangerous to load or is it not a big deal? this is my first time reloading so i want to find safe combinations.

re: "Major", i don't think it refers to power factor since there are different PF for IPSC/USPSA and the different classes.

anyways, i found a link where i can ask load questions at Accurate:

http://www.accuratepowder.com/askatech.htm

i'll see what they say....

thanks people!
 
mild-to-moderately compressed charges tend to be more accurate. heavily compressed charges sometime have troubles w/ the bullet seating itself longer over time. the problem does occur on occasion, but is not real common.

as far as safety, they are no more inherently dangerous than any other load.
 
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