Smeared Top Edge on Truncated Cone

[cabezaverde]

Hi Guys,

I have encountered the same problem with Lee's truncated cone boolits in 9MM and 45 auto.

That is, when I size them in my lubesizers, I am getting a smear at the top band on the boolit. This would be the band that one would usually seat to so that just a smidge is showing.

After sizing, the top edge has become elongated towards the cone, and is usually uneven arond the perimeter of the bullet.

In both cases, I am reducing the diameter .002 to .003. Any tips for curing this one?

[HangFireW8]

...
After sizing, the top edge has become elongated towards the cone, and is usually uneven arond the perimeter of the bullet.

In both cases, I am reducing the diameter .002 to .003. Any tips for curing this one?

Yes. Stop reducing the diameter up to .003" in one step.

Is that really necessary?

Also, do you have a really old straight sizing die, or one of the more modern (40 years or less) dies that taper a bit?

-HF

[cabezaverde]

The sizers are of the newer type.

[fecmech]

If you are using a Lyman type sizer/lube maybe your top punch doesn't fit well and is pushing crooked or possibly you are bottoming the bullet hard in the die and distorting it?? The Lyman top punch for their TC 9mm bullet would not fit the Lee well because the Lyman bullet is a sharper point so to speak than the Lee. I'm not exactly sure what you are saying here though.

[lwknight]

You might run through a Lee push through first. The Lee push through is very fast. I can do 500 in about 30 minutes easily.

[geargnasher]

Are they round before hitting the sizer? Is the sizer ram worn out in it's bore?

Gear

[Dale53]

The set screw for the nose punch of a sizer can cause the nose punch to be off center. Instead of using the set screw, put a smear of grease around the opening for the top punch and let the top punch "self center". The grease will hold it quite well. Others have ground or turned a groove on the top punch where the set screw hits it. Then leave the set screw loose (but tight enough to secure the top punch) so that the top punch is loose but doesn't fall from the socket.

FWIW
Dale53

[cabezaverde]

I am using a flat top punch in these in the hope of the boolits self centering.

[9.3X62AL]

I am using a flat top punch in these in the hope of the boolits self centering.

This didn't work for me. Try a "domed" top punch design with the Lee TC boolits--they self-center quite well with their radiused point edges in the hemispherical cavity.

[noylj]

1) Try shooting some as-cast and tumble lubed bullets to see if you even need to size and lube.
2) Try a Lee sizer (cheap enough to try)
3) Get a custom top punch
4) Change alloy to get the as-cast diameter that you think you want. Even with the best sizing, anything over 0.002" is warping and damaging the bullet.

I shot as-cast. Before tumble lubing, I used sizers the same or 0.001" larger then as-cast diameter. Never saw any pressure signs with larger bullets and my guns shot more accurately with them.

[Red squirrel]

I too have this problem, but with a lee 6 cavity 175 gr .40 s&w mould with standard lube groove. Problem is they cast oversize and when you size and lube them with anything but a star lube sizer, the lead that is being displaced has no where to go but up toward the nose of the bullet. I use a lee push through .401 sizer first as this will displace the lead down into the lube groove, then switch to my rcbs lube-a-matic and have no problems. Only other answer i have found is to switch to a star sizer as they size nose first.

[x101airborne]

i would think sending that mold bacck to Lee would be my first option. Second, there is something out of whack. look closely at the stages of your bulet sizing. Check for alignment, contaminants / debris, etc... Cant tell without seeing, but something is rotten in Denmark.

[Cherokee]

I use the Lyman 402 top punch for the 356402 TC bullet. Works for me.