Sizing

[Ben]

A lot of people say , " A bullet will never be rounder than it is when it leaves the mold."

These people must have molds that throw bullets that are much closer to round than most all of mine. Some of mine are as much as .002 out of round. However once sized , they shoot just as well as some of my other molds that are VERY close to being perfectly round.

Some of my molds that are throwing " sub - sized " bullets will get beagled. Obviously the bullet is no longer round after the beagling.
Catch is....they will often shoot BETTER than they did previous to the beagling treatment.

Many of the old timers said , " For every .001 " you size a bullet , your group at 100 yards will grow 1 ". "

For me, I have found absolutely no truth to that one either.

I have a pair of molds , 311413 & 31141 that will throw their bullets at .314". I size them to .311 and .310 and find both of them to shoot very well.

Many of the older casters also said that a spire point cast bullet had very little chance of shooting accurately. I have a plain base Modern Bond .30 cal. , 190 gr. bullet mold that I bought from George. That bullet shot a .314 " center to center , 5 shot group yesterday at 50 yards.

So much for some of the " Old theories."

A couple of statements that I have found to be
truthful are :

" It's all an educated guess,,,, till the trigger is pulled. "

And " Those targets don't lie."

[Tatume]

My only disagreement is with the disparagement of the word "theory." I think you mean "hypothesis," which is entirely different.

[Ben]

Corrected

[captaint]

Also, Ben, the old school sizing dies had a sharp shoulder that actually "cut" the boolit, rather than a graduated rounder sizing area like we have now with our sizing dies. I do agree with you, though. I have sized rifle boolits 3 thou and still gotten great groups. Mike

[Maven]

Long ago Buckshot experimented with sizing CB's down significantly to determine whether it would have a negative effect on accuracy. If you fill all lube grooves (with lube, of course) and size concentrically, the effect on accuracy is minimal. I repeated that experiment using a .325" CB and a .314" Lee Precision press mounted sizing die. Accuracy in my Mod. 1909 Arg. Mau. was no different with normally sized .314" CB's v. radically resized ones. However, the effort to reduce them from .325" -> .314" took tremendous effort (and a strong reloading bench!).

[Ben]

UUuummm ? ? .325" -> .314", .................Yes, doing that very much will have you looking like Popeye .

Ben

[44man]

I have never seen a perfect cast boolit but got close after running a cherry again in a hot mold.
Lead, lag of a cherry at block edges or heat expansion deformation makes it almost impossible. It just does no harm at all.
It is true the more you size, the worse groups can get because you are getting away from FIT. But to take a boolit to FIT usually does no harm. Lube in grooves might keep grooves in shape but I see it doing little to also expand grooves so enough lube is still carried. Soft lead might grow in length but I don't see it with hard alloys.
Custom molds are made better today for roundness but you will never escape it.
The cavities get smaller at the center with heat expansion but get larger at the parting edges so the parting edge will always be larger. No way to cut oblong to account for expansion. Might be done with real hot blocks but that can soften cutters.
Size dies that cut are the same as those that move metal, still some imbalance. The right spin kind of negates it. The worst is still lube choice and what happens past the muzzle.
Talk about a spire point and why it was said they are bad. It was because of soft, slumping lead. A "putty" ball does not hold shape when punched with pressure.
I consider myself stupid. Don't throw math or formulas at me. I think in mechanical things and what I see. I see what I see, my imagination takes me into a gun when it fires, not some numbers some guy thought up.
Many here actually experiment and find a lot of the printed word is wrapped in a bunch of rotten meat.
Good for Ben, he is really seeing things.

[fredj338]

A lot of people say , " A bullet will never be rounder than it is when it leaves the mold."

These people must have molds that throw bullets that are much closer to round than most all of mine. Some of mine are as much as .002 out of round. ."
I agree. I think it's easier to machine a near perfect sizing die vs a mold, especially a multi cav mold. One reason I like to size all my cast bullets.

[MtGun44]

captaint beat me to it. I have a couple of old Lyman 45 dies with cutting shoulders -
they are NOT in the rotation.

Bill

[44man]

Knew a guy once that never flared ACP brass, case mouths made round boolits but left half outside! :bigsmyl2:

[cbrick]

No shortage of old wives tales floating around but at least with "sizing hurts accuracy" there used to be some truth to it. As was mentioned, sizing dies for many years did not have a taper into the final die diameter. Instead they had a sharp shoulder and instead of swaging a boolit to sized diameter as modern dies do they would slice off a side of the boolit & the more sizing the more the boolit was deformed. I wonder why that wouldn't shoot well? :shock:

Rick

[44man]

Yeah Rick, the problem was starting the boolit so the more sizing needed the more off center it could be. Easy to shave one side away.
A real out of round boolit in a tapered size die will displace metal as bad as cutting the lead away.
I wish I could establish an out of round limit but the small amounts from our molds, unless real bad, seem to not hurt.
If I could make a perfect mold I could be rich!
Had to send some molds back that were crazy out of round. I think it was the metal itself with flaws that expanded wrong.