What should your .40 mike out to after sizing?

[AZPaul]

What should the diameter of your .40s measure out to after sizing with out lube?
My Lee sizer says .401.
Should they be exactly .40 or should they be .401 before lube?

[Dennis Eugene]

what is the size of your sizeing Die? I'm going out on a limb here and guessing .40 and if so I'm thinking after a while they'll bounce back to .40. But that's just a guess. Dennis

[AZPaul]

It's a Lee sizing die. I remeasured them and they where coming out .40.

[GBertolet]

Both diameters are within die tolerences. Most casters I know size to .401. The bigger diameter usually shoots better, with less chance of leading, as they seal the chamber better. .400 leaded for me .401 didn't.

[mpmarty]

My Lee push through .401 sizer produces .401 to .4013 diameter boolits with ACWW.

[AZPaul]

My Lee push through .401 sizer produces .401 to .4013 diameter boolits with ACWW.

My Lee Bullet sizer says .401, but when I use my caliper on them it measures .400.
Would you measure before or after the lube is applied?

[GBertolet]

I don't think it really matters, other than getting grease on your micrometer. I have been told most sizer dies have a 4 to 5 ten thousandth tolerance + or -. So you can buy a .400 die and have it come out .4005 or buy a .401 die and have it come out .4006 or it could go the other way. You buy your die and you take your chances. Lyman has a chart in one of their manuals, listing diameters of various caliber molds of their manufacture, using linotype, #2 alloy, wheelweights and pure lead. It lists, as cast size, and diameter after sizing. There is a definite spring back with the harder alloys after sizing, usually a few ten thousandths with smaller diameter bullets and up to nearly one thousandth with 45 cal bullets between lino and lead, incrementally larger as the hardness increases.

[Down South]

I just ordered a .402" die from Lathesmith for my Star for one of my S&W's. The barrel slugged at .401". Have you slugged the Barrel? What diameter is the boolit as cast?
Anyway, it's not a problem to open up a Lee die a little by honing it out with fine emery paper if need be.
The boolit will be whatever diameter it is after sizing lubed or not. It may expand a little after aging depending on alloy.

[AZPaul]

I don't think it really matters, other than getting grease on your micrometer. I have been told most sizer dies have a 4 to 5 ten thousandth tolerance + or -. So you can buy a .400 die and have it come out .4005 or buy a .401 die and have it come out .4006 or it could go the other way. You buy your die and you take your chances. Lyman has a chart in one of their manuals, listing diameters of various caliber molds of their manufacture, using linotype, #2 alloy, wheelweights and pure lead. It lists, as cast size, and diameter after sizing. There is a definite spring back with the harder alloys after sizing, usually a few ten thousandths with smaller diameter bullets and up to nearly one thousandth with 45 cal bullets between lino and lead, incrementally larger as the hardness increases.

Thanks for the info. I'm pretty sure my lead is wheelweight lead.

[HammerMTB]

My Lee Bullet sizer says .401, but when I use my caliper on them it measures .400.
Would you measure before or after the lube is applied?

Measure without the lube.

I got a .401 Lee sizer at a gun show recently. Thought I got a good deal for $5. Then I looked at it closely. The inside of the die was pretty rough. I used it anyway, and got sized boolits .400"
So I got out the drill motor and some 240 grit emery. Spun away at it for a while, and tried some boolits again. Now I get .401" boolits, they are very glossy to look at and the inside of the die is very smooth.
I didn't get hurt for $5, but as with most things Lee, it needed some LeeMenting.

If your boolits are sizing smaller than you want, your solution is easy. Resize your sizer. :cbpour:

[cbrick]

AZPaul, I was reading your other thread on this subject, what size where they before sizing?

A caliper is the wrong tool to try and get an accurate boolit measurement. They are only accurate to to about .001" and some of the less expensive ones aren't that close, you need a micrometer. Calipers were never intended for precision measuring, they get you close is all.

Your alloy will effect the final sized diameter by .001" easily.

In your other thread you mentioned they were very tough to get through the die and it was shaving the driving bands, you also mentioned that you thought maybe the mould wasn't closed completely during casting.

There is also the outside chance that you got a mis-marked sizing die.

Assuming they are .400" what does the bore slug at?

Rick

[Chris]

I just picked up a Lee .401 die and it's sizing to .398. I shot some of them and it leaded BADLY. I only sized since a lot of the rounds I ran unsized were at .403 and above and would not cycle reliably in my Glock. So now I have to figure something else out since unsized is too big and sized is too small.

[GBertolet]

Chris, I suspect you bullet diameter is too small, so hot gas with vaporized lead is slipping by the bullet and soldering itself to the barrel as it condenses, near the chamber end before it upsets and seals the bore. There are a couple of solutions here you can do. You can lap out your sizer die using a wooden dowel wrapped in emery cloth to open it up 1 to 1 1/2 thousandths, Which I have done to several of my Star dies, or buy a Lee carbide factory crimp die for .40 cal for around $ 15. With this you could use tumble lubed unsized bullets and the die will slightly size the loaded round, insuring chambering. I use this method as my mold drops at .402 and I use a .402 sizer die. Although rounds chamber fine unsized, I use my gun for IPSC shooting and the Lee Die gives me a little bit of extra reliability insurance.

[blackthorn]

Quote
"What should the diameter of your .40s measure out to after sizing with out lube?"
The diameter needed is 1 to3 thousandths over the size of your bore (found by "slugging").
Have you slugged your bore today? If not-------
Have a great day.

[Jbar4Ranch]

Where do you find a .402" sizer die? Kinda lookin' for one myself. One of those $45+shipping custom jobs from Buffalo Arms? (Lyman/RCBS style)

[Down South]

Where do you find a .402" sizer die? Kinda lookin' for one myself. One of those $45+shipping custom jobs from Buffalo Arms? (Lyman/RCBS style)

A couple members build them for much less that you can buy them from the manufacture. Lathesmith builds mine for the Star. I think that Buckshot builds them too or can open one up if need be.
http://castboolits.gunloads.com/showthread.php?t=62874

[GBertolet]

I opened up a .401 die to .402 by lapping it out. It was easy. If you want a new one, I would contact Lathesmith who can make or modify a die to suit.

[AZPaul]

I opened up a .401 die to .402 by lapping it out. It was easy. If you want a new one, I would contact Lathesmith who can make or modify a die to suit.

What is lapping it out?

[GBertolet]

There are two ways I use to lap out a mold. First you can get a wooden dowel smaller than the die diameter. Either wrap a piece of emery cloth around the end or make a slot lengthwise at the end of the dowel, slipping a piece of emery cloth inside. Match the length of emery cloth to the diameter of what will fit inside the die. Chuck the dowel in a variable speed drill and run at a slow speed, running up and down the length of the die, stopping about every 10 seconds and pressing an unsized bullet through periodically and measure to check your progress. I like to use medium cloth to do the bulk of the lapping and finish up with fine crocus cloth, once your final diameter is reached. If you have a Star machine you don't have to take the die out of the press. You can go up from the bottom. The second method is to get a lubed bullet of that caliber and coat the bullet with lapping compound. Use a medium range grit. The grit will stick to the bullet lube. Keep running the bullet through the die, adding more lapping compound to the bullet as needed, periodically running an unsized bullet through, and measuring to check your progress. Which ever type of press you have, you can do this in the press. I like to use JB bore paste for the final treatment, as it is very fine. Be sure to clean out the die afterwards to remove any left over abrasives for either method. Also I would toss the first few bullets I sized afterwards, as the bleed holes in the die will have leftover abrasive in them. Both these methods work best for small increases, maybe one thousandth or so. The beauty of doing it yourself is, you will know exactly your diameter with your bullet alloy, because you measured it as you made it to your standard. If you have no 40 cal sizer dies to start with, and wish to have a .402 I would contact Lathesmith to buy the exact die you need from the start.

[Echo]

IMHO, with autoloaders, one wishes to load the largest diameter boolit that will reliable chamber in the pistola. The barrel will size it down to the exact size needed.

And lapping out a Lee sizer should be no challenge. If it were me, I would use the slotted dowel/240 grit method, followed by much finer grit, even crocus, for final polish.

[GBertolet]

I agree Echo, also oversize bullets in a revolver are good too.