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Tapered nose dies now available

Posted: Tue Dec 20, 2016 2:53 pm
by mtngun
You may have noticed that nose dies are now available in certain calibers, listed in the "proven designs" menus.

These are tapered dies that fit Lyman and RCBS lubrisizers. They are intended for sizing down (not up) the noses so that the resulting bullet is a glove fit in your chamber. Yes, it's an extra step, but the beauty of it is that any bullet, providing its as-cast diameter is big enough, can be made to fit your throat like a glove. 8-)

The die comes with a long flat punch, used to push on the base of the bullet.

The inside of the nose die looks something like this:

The suggested procedure is:
1) Apply the gas check & lube in a conventional lubrisizer die. There are two reasons why it's a good idea to lube before, not after nose sizing -- one, if you try to lube a tapered bullet in a lubrisizer, it won't form a good seal and lube may squirt out. Two, lube reduces friction in the nose die.
2) Size the nose in the nose die.
3) (Optional) Size the bullet in a push-thru die or in conventional lubrisizer die, just in case the base was unintentionally bumped up during step #2.

If you dedicate a lubrisizer to nose sizing and set things up like an assembly line, the 3-step process only takes 10 - 15 seconds per bullet.

Why not use the nose dies to "bump up" an undersize nose? Two reasons:
1) A lot of force is required to "bump up" a hard bullet, and lubrisizers are not that strong. I've learned the hard way to respect the limitations of lubrisizers. ;)
2) If you use enough force to "bump up" the nose, the tip of the nose will be deformed to fit the cavity of the die's push stem, which is usually a simple 60 degree cone. Whereas if you are only sizing down, then deformation to the tip of the nose is minimal.

For now the nose dies are offered in a few popular target calibers, and a few popular throat angles. Reamers are spec'd by caliber, taper, and final diameter. Example: 6mm, 1.0 degree x 0.2375".

Would you like a caliber or a throat angle that is not listed? Well, I can do that if you want to pay the cost of the reamers, typically $80 - $100 in addition to the regular price of the nose die. The cost of the reamers will be waived if you convince 9 of your buddies to join you in a group buy of 10 or more dies.

Alternatively, if you already have the throating reamer, you can loan it to me and I'll make the nose die for no extra charge providing I also have the correct final diameter reamer in stock.

Would you like a final diameter that is not listed? I can do that, but if I don't already have the appropriate reamer then I may have to charge $20 or so in addition to the regular price of the nose die. Ask, because I already stock some reamer sizes that are not listed.

Obviously, any time a reamer has to be ordered, that may delay delivery of the nose die.

Re: Tapered nose dies now available

Posted: Fri Feb 03, 2017 8:55 am
by mtngun
Here is how I set up the sizing depth of the nose die, in a RCBS lubrisizer.

How to measure the sizing depth with calipers. I use a spreadsheet to keep track of the preferred sizing depths for each bullet, cartridge, etc.. This picture was before I modified the lubrisizer.

The knurled locking screw works great, much easier to use than the original locknut. A tiny piece of copper keeps the locking screw from damaging the threads of the depth screw. The milled surface results in more consistent measurements with the calipers.

Re: Tapered nose dies now available

Posted: Sun Mar 05, 2017 2:14 pm
by mtngun
Getting the perfect snug slip fit on the nose is tough sometimes.

Krieger barrels seem to have a tighter bore -- 0.3000"-ish -- than Shilen, which is closer to 0.3005"-ish. It's hard to predict how much engraving a bullet will tolerate, but the hard tapered bullets that I usually shoot won't tolerate much engraving at all. I've decided that it is best to err on the small side for the small end diameter of the nose die, then you always have the option to hone it larger if the need arises.