WHAT THE HECK...how did my sizer SHRINK ?

[mike in co]

GUYS,
years back when i got started on the old shooters forums, i honed a 429 sizer to produce a 4316 boolit. went slow, cleaned, sized, measured the results on a sized boolit, honed more and did it all over again. till i got the size i wanted. all was good...small groups.....sub 1" at 25 yds.

when i shot at the nevada match, i was not grouping well with either lever gun nor with 7.5" SRH.

had no idea why.

today while working with the new mold from miha, a 290 hp, my 4316 sizer produced a 4295 boolit!

someone tell me how a sizer shrinks ??

( my only guess is heat when honning...but...sure i let it cool when i did this)...and yes i only have 2 sizers...the 429 honed out and a 431 that is actually a 430...lol

what happened
inquiring minds want to know....

thanks
mike in co

[AZ-Stew]

Did you do your sizing when ambient temp was cold?

Did you drop your micrometer?

Inquiring minds want to know...

Regards,

Stew

[RayinNH]

Mike,what size are or were the boolits before sizing? Any chance they dropped from the mold at .4295? I can't imagine you would generate enough heat just honing to swell the die...Ray

[snuffy]

A tube or ring gets larger in all dimensions when heated. Then when it cools, it returns to it's former dimensions UNLESS material is removed during the heating process.

We heat shrink gears on shafts at work by heating the gear in a common oven to 400 degrees. They slip effortlessly onto the shaft. After cooling it would take a 25 ton press to take them apart.

[243winxb]

Lyman has the answer on the website under FAQ Different alloy different size.>
Q: I have run my bullets through the sizing die, however they do not come out at the expected diameter. These were cast in wheelweights, would that make a difference?
A: Yes, bullets cast in pure lead or wheelweights will come out smaller, bullets cast in linotype will come out larger. This is due to the spring-back of the bullets being sized. The sizing dies are made to produce the diameters using #2 alloy.

[mike in co]

they are aprox 432...as cast.
its the same with two mic's

it was honed with finer and finer emery.

thanks
mike in co

[HeavyMetal]

An alloy change may case this.

It could have been dropped

It could be the wrong sizer die, have you done an inventory of your dies? Seen a few threads recently where guys found stuff they bought and forgot they had.

Posible that you got a die in some tradin stuff and didn't realize it??


Tick'd off SWMBO and this is her revenge??

Interested in what you figure out the problem is!

[GabbyM]

in my Star I've had dies gaul up with lead then start to put out undersized bullets.
A bronze brush chucked in a drill plus your favorite gun cleaner will make short order of lead in a die. Then you probably need to polish the die some.

[mike in co]

well...i have no idea what happened. i have very clear notes on the super red hawk. honed the die to 3216...years ago prior to my lathe.
i took the die, and re honed in my lathe and when done, cooled and warmed to room temp and i went past at 4323...dang....took the 430 die polished it a little(too much) and got a solid 432..which does work.....so thats where i am.

will do some reading on hp fillout, and eventually fix the gc dia on the mold, but will shoot a bunch wihtout them first.

i have no idea what happened....

mike in co

[fredj338]

I think it's possible to have enough variation in alloy to give you slightly diff. diameters even shortly after sizing. I'm not sure 0.001" diff. Is the bullet dia. measured immediately after sizing or a day or more?