The Firing Line Forums - View Single Post - .30-06 reloading tips

Slamfire · June 22, 2007, 01:52 PM

Domino: You did not state whether you are loading for a semi auto (like a Garand) or a Bolt gun.

I am going to assume it is a bolt gun. If you are loading for a Garand there is much more you need to know.

For all my rifles, I full length resize for function. Partial sizing or neck sizing increases the chance that the case will be too fat or too long which makes the bolt hard to close. Neck sizing is advocated by people who will make unsubstantiated claims about longer case life, better accuracy, etc. Since I have taken brass twenty two reloads in a gas gun, and won matches using it, full length sizing is fine for me.

The set up instructions given with sizing dies assume a lot of things. And seldom following the instructions do you ever get the brass sized to the correct length. If possible you would like to set back the case shoulder about .003” less from its fired length. In no circumstance do you ever want to size it more than .006” as you are likely to get a case head separation on the next firing. There have been instances where I followed the set up instructions and I got a crush fit in the rifle chamber. The sizing die was too long and did not set the shoulder back enough. In those instances I have had to grind material off the bottom of a sizing die to get sufficient case sizing. Just take the instructions that the factory sends with their dies, and toss out the part that tells you to size to the shellholder. Or shellholder plus a ¼ turn. You will find that such guidance is inaccurate at best, rubbish on the average.

To properly size cases to a correct length you will need a new piece of equipment that has not been mentioned: case gages. I really like the Wilson type case gage. You size your round and drop it in the gage. This gage measures the distance between shoulder and base. It is a "go" and "no Go" gage. And it is a true measurement, as I have dropped my chamber headspace gages in my wilson gages and found perfect agreement between them. You want to size your case between “go” and “no go”, and for my rifles, I size everything to gage minimum.

This web site is really useful for showing how to use case gages. I recommend looking at the pictures, and it explains the special case gages needed for the belted cartridges.

http://www.realguns.com/Commentary/comar46.htm

The midsection of the Wilson gage is cut big. It only measures headspace. What the Wilson type gage and the other functionally equivalent gages do not measure is "fatness". This is an important measurement for gas guns and should be controlled.

For those who want more sophistication than Wilson case gages, Sinclair makes gages that will measure the fired length of a case, and allow you to set the shoulder back from that dimension. I do have these Sinclair comparometers, found them useful when case gages are not available, but they are more complicated than a “go”, “no- go” gage.

June 22, 2007, 01:52 PM	#13
Slamfire Senior Member Join Date: May 27, 2007 Posts: 5,261	Domino: You did not state whether you are loading for a semi auto (like a Garand) or a Bolt gun. I am going to assume it is a bolt gun. If you are loading for a Garand there is much more you need to know. For all my rifles, I full length resize for function. Partial sizing or neck sizing increases the chance that the case will be too fat or too long which makes the bolt hard to close. Neck sizing is advocated by people who will make unsubstantiated claims about longer case life, better accuracy, etc. Since I have taken brass twenty two reloads in a gas gun, and won matches using it, full length sizing is fine for me. The set up instructions given with sizing dies assume a lot of things. And seldom following the instructions do you ever get the brass sized to the correct length. If possible you would like to set back the case shoulder about .003” less from its fired length. In no circumstance do you ever want to size it more than .006” as you are likely to get a case head separation on the next firing. There have been instances where I followed the set up instructions and I got a crush fit in the rifle chamber. The sizing die was too long and did not set the shoulder back enough. In those instances I have had to grind material off the bottom of a sizing die to get sufficient case sizing. Just take the instructions that the factory sends with their dies, and toss out the part that tells you to size to the shellholder. Or shellholder plus a ¼ turn. You will find that such guidance is inaccurate at best, rubbish on the average. To properly size cases to a correct length you will need a new piece of equipment that has not been mentioned: case gages. I really like the Wilson type case gage. You size your round and drop it in the gage. This gage measures the distance between shoulder and base. It is a "go" and "no Go" gage. And it is a true measurement, as I have dropped my chamber headspace gages in my wilson gages and found perfect agreement between them. You want to size your case between “go” and “no go”, and for my rifles, I size everything to gage minimum. This web site is really useful for showing how to use case gages. I recommend looking at the pictures, and it explains the special case gages needed for the belted cartridges. http://www.realguns.com/Commentary/comar46.htm The midsection of the Wilson gage is cut big. It only measures headspace. What the Wilson type gage and the other functionally equivalent gages do not measure is "fatness". This is an important measurement for gas guns and should be controlled. For those who want more sophistication than Wilson case gages, Sinclair makes gages that will measure the fired length of a case, and allow you to set the shoulder back from that dimension. I do have these Sinclair comparometers, found them useful when case gages are not available, but they are more complicated than a “go”, “no- go” gage.