Hardness testing

[reloader28]

I've been wondering about this awhile and aint really found an answer anywhere.

Why would running your bullet thru the sizer soften the surface????

A file is a heck of alot rougher on a bullet than the lube/sizer, but you have to file it flat to check the hardness. When I check it, its pretty hard.

Would it really make a difference?

There must be a good answer, but I sure cant figured it out on my own.:lovebooli

[RobS]

Actually working the bullet with a file work softens it too. How much depends on a few variables. Lead is not like other metals for as you work it the alloy will become softer..........on the other hand continue to work a metal paper clip back and forth and it will get to the point where it will get hard enough it breaks.

I've found that if I size a bullet directly after casting it doesn't loose much if any BHN hardness as my test indicated (1 BHN or less) but those tests were on water dropped and heat treated bullets not air cooled.

[sagacious]

Properly used, a file mainly removes material from the surface.
Properly used, a size die cold works the surface.

Whether sizing-softening makes a difference is fodder for discussion.

[Bret4207]

Get a Cabine Tree tester and you don't have to file.

[44man]

I size right after casting if I feel like it. I have many boolits that have not been through a die yet and they are a year old.
They shoot the same no matter.
Just one of those things that are not very important unless you shoot one hole groups.
I feel the LBT hardness tester is the easiest to use. Using a microscope and a scale would find a trash can fast! :bigsmyl2:

[reloader28]

Thanks guys.

I've heard that (as everyone has) ,but it really must not change the BHN much. I oven heat treated some 500 S&W boolits to 29.9 BHN. That was after the file and was I wondering how much it softened it. I guess next time I do it, I'll have to file one first, then heat treat and measure.

For checking hardness no more than I do, I cant see spending more than $50 on a hardness tester. Maybe a few years down the road, but the Lee seems to work fine for now. It just dont seem terrible important to me, other than to get an estimate of the pressure range. That was just a question I had and couldnt really find an answer.

Thanks again.:bigsmyl2:

[MtGun44]

Filing CUTS away material. Sizing moves the material, the deformantion distrupts the
grain structure in a way that softens it. In iron alloys, this same sort of deformation
will harden the metal. Different metals, different grain structure, different response.

Bill

[reloader28]

^^^That makes sense. For some stupid reason I didnt quite get that when it was mentioned earlier.:veryconfu