seating ?

[hoggunner]

When seating my bullets I am getting as much as 10 thousands difference in col. I am using a lee press and hornady dies. These rounds are my plinker rounds of 7 grains of titegroup and 240-grain hornady swc. Brass is all trimmed the same size. These are 44 mag rounds and I know that the difference will not matter much in my shooting but it bothers me as to why the difference. Any and all ideas are very much appreciated.

[EVOC ONE]

I experienced similar problems while reloading. 

I have found a few areas that I believe cause/contribute to the problem:

1st:  Using different shell holders.  In several popular calibers, I have more than one shell holder.  One for the RCBS priming tool and for the press.  A couple are not of the same brand.  From brand to brand they can differ in dimension.  Even on same brand holders, the size can differ.  I found this out when using one I purchased over 25 years ago and a new one for the same calibers.

2nd:   I have found that not all projectile lengths are identical.  So far, this has occurred with Remington bulk in rifle (.284), pistol (.429) and with Speer (.284) and Hornady (.310).   

3rd:  Be sure that the area of the press where the shell holder sits and the holder is free of dirt and/or powder residue. 

4th: Check that the seater die is tightly secured to the press and that the surface area is clean.  Also make sure the seater stem is properly secured.

Overall, I have not noticed any effects on accuracy that I would consider a result of any of the above.  But then, I'm not a bench rest shooter and have no precision made firearms.  I also regularly inspect my cases for fatigue and pressure signs.   Again, I've seen nothing out of the ordinary that I would contribute to above.

 

EDIT 4/13/08:  One more area I forgot to mention:  Rim thickness.  I've noticed a difference in the thickness of the rim on different brands of .303 British brass.  I use mostly Remington, but also Winchester and Norma. 

[Kurt L]

As stated above.
the biggest difference is the base to tip length on bullets.
if you use a rsbs mic gauge or stoney point or now lock n load gauge
and measure from the shells head to the bullet olgive this is the part of
the bullet that is the bore size and would touch the lands  you will see your difference
shrink.

[Throckmorton]

If you are using 1 die to seat and crimp,the die could have some lube or lead...or.both..jammed up inside from bullets being shaved.
Dies do need to be cleaned occasionally..I found out the hard way.

seating ,then crimping with a seperate die pretty much eliminates this problem,I use seperate dies for all my cartridges.

[Catfish]

Forget it. If you are shooting this ammo through a revolver .010 won`t mean a thing with the long jump out of the cylinder and onto the forcing cone. If you are a purest and have to get that .010 down check for wax build up in the seating die. Make sure that the medoplate on your bullets is the same. Are you useing a seating die with a seater for round nose bullets with semi-wad cutters, or vise versa?

[LaOtto222]

This is a common occurrence. The distance from the octave to the base is the important measurement. There are gages made that measure this distance. Sinclair International makes one. It is like a large nut with different size holes (for different diameter bullets) drilled in it in every flat and chromed. You slip it over the bullet and measure the whole distance from the base of the cartridge to the opposite flat on the gage. This will give you a much more consistent reading. The bullets vary in length, especially the tip area so this gives you a much more consistent reading.