The Accurate Reloading Forums
slack bullet fit

This topic can be found at:
https://forums.accuratereloading.com/eve/forums/a/tpc/f/2511043/m/59810426

15 January 2003, 10:33
griff
slack bullet fit
Can anyone tell me what Diameter the mandrill on a 25-06 lee neck sizing die should be?
I have measured it @ 253.9.
I have a full length rcbs which gives a tighter bullet fit, but don't want to full length every time.
I have tried rotating the bullet through 45 degrees so that it crimps in 8 places rather than 4.
What is the reccomended interference fit!

Many thanks

Griff
15 January 2003, 10:52
Bigdaddytacp
quote:
Originally posted by griff:
Can anyone tell me what Diameter the mandrill on a 25-06 lee neck sizing die should be?
I have measured it @ 253.9.
I have a full length rcbs which gives a tighter bullet fit, but don't want to full length every time.
I have tried rotating the bullet through 45 degrees so that it crimps in 8 places rather than 4.
What is the reccomended interference fit!

Many thanks...Griff the usual is to compress the brass .002 to .003 less than the desired final fit....I would take the mandrel and spin it in a lathe or electric drill and use sandpaper in a fine 320/400 grit and polish it down a couple of thousandths and try a shell...if it is tight let it go...if not polish some more for another .002 untill you get a decent neck tension....the brass isn't getting brittle? is it from many loadings....? if not the polished mandrel should fix the loose fit on the bullets and will work smoother anyway....HTH..good luck and good shooting!!

Griff

15 January 2003, 11:04
griff
bigdaddytacp,
Have loaded the shells about 4 maybe 5 times, they are rws 270 cases which i have full length sized and then neck sized after the first firing. They seem to be in good order with no splits and very little sooting on the neck after firing.
The reason I want a tighter fit is that I am using 90gn sierra gmk's and for me to seat out to the lans there is very little purchase on the bullet.

Many thanks

Griff
15 January 2003, 12:14
sjf
The key to using a lee collet neck sizing die is to adjust the die so the ram is not at the top of the stroke.

Screw the die in deep enough so that the shellholder bottoms out on the die and then give a good solid push down on the ram arm after it makes contact.

The problem with having it at the very top of the ram travel is that the ram cams over and does not apply enough preasure on the bottm of the die. Preasure on the bottom of the die is what causes the collet to size the neck.