Micrometer seating dies

B

bluechip

Guest
I just dis-assembled my Redding seating die and took some measurements with a set of pin gages. The bore that the case neck enters is .272, obviously for standard neck cases. I am shooting a .262 neck case so wouldn't it be better to have a custom bore a bit tighter, say .263-4?
 
bluechip said:
I just dis-assembled my Redding seating die and took some measurements with a set of pin gages. The bore that the case neck enters is .272, obviously for standard neck cases. I am shooting a .262 neck case so wouldn't it be better to have a custom bore a bit tighter, say .263-4?
Click to expand...

It may or may not matter...FWIW, I tied a record at a night match a couple of years ago, shooting a 220 Beggs while seating the bullets using a 6PPC seater die. Go figure! I think this is an example of the many things we obsess over a bit too much. That said, a better fit won't hurt a thing. If you think it helps..then it does. Quantifying it beyond the mental aspect may be harder to do if the difference is not enough to stand above the noise of other factors, such as conditions. It is generally true that runout is more often than not, induced during sizing much more than during the actual seating operation.
 
One of the variables that has an effect on the need for fit is whether a bullet is FB or BT. BTs will follow the neck better when seated using a loose fitting die. I came across this when fire forming PPC cases using a method that James Mock wrote about, using .22 caliber bullets in a 6mm barrel. I used the cheapest .22 bullets that I had, which happened to be 55 gr. FMJ BTs, seating them in the neck of slightly expanded .220 Russian cases, using a Wilson 6PPC seater. The results were remarkably straight, considering that new .220 Russian cases typically have about .002 runout on the ends of their case necks. On the whole issue of Concentricity, as it applies to a .262 neck 6PPC, shooting FB bullets that have a pressure ring, that are seated into the rifling...I have found that they straighten when the bolt is closed. This may not be the case for rounds that have thicker necks, more shank in their case necks, loaded with different style bullets.
 
bluechip said:
I just dis-assembled my Redding seating die and took some measurements with a set of pin gages. The bore that the case neck enters is .272, obviously for standard neck cases. I am shooting a .262 neck case so wouldn't it be better to have a custom bore a bit tighter, say .263-4?
Click to expand...

Most notice that I use Redding Dies.

For my 6PPC and 30 BR Competition Rifles, I make another inner sleeve with my clambering reamer. I use the stem that comes with the Die.

They are not that difficult to make. I use Stressproof Steel.
 
jackie schmidt said:
Most notice that I use Redding Dies.

For my 6PPC and 30 BR Competition Rifles, I make another inner sleeve with my clambering reamer. I use the stem that comes with the Die.

They are not that difficult to make. I use Stressproof Steel.
Click to expand...

Are you saying that you make a bushing with a wall of only .004-.005?
 
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