powder air space

[3 weelin geezer]

I was just noticing that factory ammo seems to have an air space betwen the bullet and powder. It says in the reloading book from the library that using too little powder for lower velocities is like putting an obstruction in the barrel. It also does not recommend ramming the powder either for obvious reasons (too heavy a load). It says to use a filler or some sort of wad to hold the powder back to take up dead air space for good ignition and to prevent too high pressures building up as in an obstructed bore. I don't have a reloading manual that states how much of a certain powder for what velocity yet. I am just getting into this and don't yet have all the stuff.

[Jim Watson]

All that is highly hypothetical. Stick to published lab tested data and you will be ok even though there is some airspace. Inert fillers are highly specialized and can cause more trouble than they prevent in ordinary loads. I don't use 'em.

[Zekewolf]

I'm betting that Jim knows a lot more about reloading than the guy who wrote the book to which you refer.

[Rangefinder]

As a safety rule---If you're handloading, use the manual written by the bullet manufacturer for whatever bullet you are intending to load. They will give you everything you need to know---powder types, grain weights for the bullet and powder being loaded to produce desired safe pressures and velocities, etc. Don't deviate from those until you know exactly what you are deviating from and why, and don't experiment with ideas from unreliable sources---it can lead to extremely dangerous consequences.

[Olaf]

It's perfectly alright for there to be some empty space inside the loaded cartridge. The important issue is : how much empty space ? generally, as long as a particular charge fills the case at least 60 %....it will be safe - AS LONG AS THAT PARTICULAR POWDER IS SUITABLE FOR THE CARTRIDGE IN QUESTION. The best accuracy tends to occur when the case is filled nearly to capacity - but this requires a powder with a density/ shape such that the amount needed to do this will still constitute a safe load. The commercial ammo companies know all of this...and they design and test their ammo to be safe, yet as reliable and accurate as practicality allows. People who handload seldom achieve 100 % load fill for a given cartidge...but can still get good results anyway. This is because the optimum charge weight (for accuracy) may well not completely fill the case. For instance, my own loads, optimized for my particular rifle (1 MOA or better)... only fill the case about 85 %. Still, they are quite safe - and do just fine.

As someone else mentioned, fillers can be more trouble than they are worth. IMO, they are best avoided. If trying to achieve the best case filling one can get.... the thing to do is try different powders (that are suitable for the particular round - not all are).... based on their relative volume. Often, this information is published in the reloading books. It is a simple matter to do the math and determine which (suitable) powder will best fill the case. However, this does not guarantee that that particular powder will work best in a particular firearm. That can only be determined by experimentation.

[caz223]

Until you have practical experience, a chronograph, and several trusted sources of data, you're shooting in the dark.
Several 'cheap' pieces of data for case/powder/bullet selection are nice, and sometimes are found in unexpected places.
For one, the little slider chart that comes with the lee dipper set.
This indicates how much of their listed powders are in which scoops.
For example, if you want a .357 mag full to the bullet, figure out which scoop is closest to the right level, .7, .9, 1.3 cc, etc.
Then look up load data for that bullet weight.
Set the slider to the right scoop size, and see what powders come the closest.
But after doing that a few times, certain powders become your favorites in certain calibers.
List the calibers and bullet weights you're interested in, and some of us will have powders that have worked well in the past.