Sizing-how much is to much??

[blysmelter]

How much sizing is to much? .005 , .010 , .050?
My plan is to try sizing some .500 Minie-boolits down to .475 but if it is a very stupid thing to do I see no reason to spend money on a sizer die:-)

[38 Super Auto]

I think there are subtle effects to sizing: you are essentially swaging the bullet by a small amount. I don't know if there is any hardening or softening of the alloy as a result of a major sizing event.

One thing I can attest to is that, depending on the alloy, the force required to size your projectile down by a large amount can be significant.

That is my experience with sizing hard cast pistol bullets. :coffee:

[Billwnr]

I can answer the first part. Sizing .314 bullets down to .310 doesn't seem to affect the accuracy at all. I've shot 10 shot groups just over MOA in my 1903 that way.

Unless the sizer smears your lead slug during sizing I wouldn't think it would hurt anything.

[Dale53]

While NO sizing is "best", it is more HOW it is sized that damages bullets than HOW MUCH they are sized. If you use a Lee "push through" die you can reduce much more than using a Lyman or RCBS sizer as they may not size the bullet straight and can bend a long, soft bullet. The Star works much like the Lee push through but it lubes as it sizes.

Dale53

[Razor]

I've sized lubed .326 down to .313 in a LEE sizer with no problem..
Unlubed...a lot harder, and the grooves kinda "smear"..
Got good accuracy with'em too...


Razor

[Shiloh]

Good info here about HOW one sizes a boolit. Sounds like the LEE system is th way to go if one is sizing down more than a couple of thousandths.

It seems like a good way to do "Step" sizing. That is, Take 'em down first with the LEE sizer, and finish with the lubrisizer to lube and gas check at the desired finished size.

Shiloh

[miestro_jerry]

I would go with the Star sizer, to me it is just a real work horse and precision machining that lasts thru many 10s of thousands of sizings.

Jerry

[Buckshot]

..............I have a M1909 Argentine Cavalry carbine. WHile I can handle the .314" grooves the .303" lands were a problem. Via 'bumping' the nose I could get pretty good accuracy, but bumping isn't 100%. As an experiment I took some Lyman 323470's which drop from the mould at .325". These I lube sized .323". I then ran them up through a Lee .314" die. Loaded them up and fawrd'em off and the accuracy was just fine.

So it's not so much how much you size down, but more 'HOW' the sizing is done, and does it damage the boolit? I was lube-sizing some Lyman 311284's once and noticed a couple looked odd. The odd looking ones were being bent at the scraper groove above the top drive band.

................Buckshot

[Springfield]

You can size with the Star without lubing, just turn off the pressure until the last sizing, then lube and size at the same time. I have sized .454 bullets down to .429 without breaking anything, but they were soft bullets.

[Lloyd Smale]

ive taken 460s to 452 and 514s to 500 but i think 500s to 475 might be a tad to much.

[Char-Gar]

There are way to many variable to codify a number as the maximum a bullet can be sized. The answer to your questions is.... It depends.

[blysmelter]

ive taken 460s to 452 and 514s to 500 but i think 500s to 475 might be a tad to much.


Having taken a second look on this bullets I do not think they will survive the downsizing. The grooves will most likely collapse.

So than I have two options, enlarge a 45cal mold or make one.

[Larry Gibson]

I prefer the Lee push through if sizing more than .002-.003. While I prefer to shoot 'as cast" and let the throat size the bullet I've found that accuracy of sized down bullets is a matter of how you do it as mentioned. When sizing down quite a bit (.325 to .314 for example) another thing to consider is the depth of the lube grooves. Many times there's not much groove left if the plain bullet is sized down. However, if the bullet is lubed before sizing down the grooves most often are not smeared away as liquids (the lube) are not readily compressable and the grooves seem to get swaged deeper retaining the lube.

Larry Gibson

[leftiye]

Bly,
Take a look at Slughammer's thread "making a drive band cutter" in Gunsmithing form. It's the absolute cleanest thing I have seen yet in opening up a mold!