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View Full Version : Bullets for BHN testing...



montana_charlie
08-23-2009, 02:58 PM
A random thought just breezed through while I was collecting bullets to take out to the shop for filing. That is...filing flats for hardness testing, so there is a good surface for the indentor to leave a dimple.

If a guy had a spare mould block half, constructed to mate up with one of his regular moulds, but having no cavity cut...it would produce 'half of a bullet' when used with the 'normal' half of the bullet mould.

Instant lengthwise 'flat face' for hardness testing, and you wouldn't be making the impression on either the nose or base...but in the middle of the bullet's body.

Hmmm...

CM

Gunslinger
08-23-2009, 04:20 PM
Yeah you're right.... hmmmm..........??

snaggdit
08-23-2009, 06:47 PM
I would be interested in buying said flat halves if one of the members with a machine shop could produce blank halves for say lee 2 cavs, six cavs, lyman 2's you get the idea. Is this doable for a fairly low cost? I have a lee hardness tester and this would be much easier to test on than filing. Also, I always wonder if I am filing off a harder surface, making my measurement slightly less accurate. Great idea. In a post a few weeks ago, a member posted information to the effect heat treatment actually goes all through a boolit but equally? It was in regards to battery plates and they do not have the same geometry or volume (thickness wise).

leftiye
08-23-2009, 07:24 PM
There are blank Lyman mold blocks that I see from time to time on evil bay.

runfiverun
08-23-2009, 09:15 PM
you could get 22 molds and have them cut.

wallenba
08-23-2009, 10:02 PM
:DOh boy, now ya dunnit....gone got everbody thinkin':D

geargnasher
08-23-2009, 10:24 PM
Locking pliers + 36" horizontal belt sander = flat boolits in under 1 second.

Lee recommends testing a cut surface, not a cast surface for best results.

Gear

Marlin Hunter
08-23-2009, 11:06 PM
It is not worth it. You would need to wait for the mold to be cold before you could reassemble it into a useful boolit mold. You might as well have a separate mold with a single hex type boolit shape. You could mold 1 hex boolit for every 50 other boolits to get an idea of the average hardness your boolits are running.

Someone could cut an aluminum mold with a flat mill with the sides tapered. I think they make endmills with about 2 degree reliefs

something like this: (dots are used to help it format correctly on the screen)
._
/..\
\_/


P.S. you would not need a sprue plate since you do not need a flat base.

Marlin Hunter
08-23-2009, 11:07 PM
Locking pliers + 36" horizontal belt sander = flat boolits in under 1 second.

Lee recommends testing a cut surface, not a cast surface for best results.

Gear

Wont the heat from the sander alter the hardness?

JIMinPHX
08-23-2009, 11:55 PM
So what do you have against 10 seconds with a file?

qajaq59
08-24-2009, 07:21 AM
Take the side of the mold without the pins, hold a piece of flat stock against it with pliers and pour. You'll have half a bullet. Don't use the sprue plate .

HeavyMetal
08-24-2009, 09:32 AM
I think you guys are over thinking this idea!

First Lee recomends filing a flat spot on a boolit so you can have a"surface" to test on not because inside is harder than outside. Very few boolit designs are dead flat. They advise against the base of a boolit fopr testing because of voids???

What I have planned: I have two very beat up Lee molds a single and a daul cavity. I will take the single, pull it off the handles true up the base in my Mill and then recut the boolit hole with a simple 3/8's or 1/2 inch four flute end mill.

The results should be a cylinder of lead with no lube grooves and have a dead flat surface on the "nose" area for hardness testing.

I see a win win here because I have revived a dead mold and secured a mold that makes test slugs that can be used for any lead based alloy with minimal effort and use plus I won't have to sacrafice a real mold for the project!

Shuz
08-24-2009, 10:42 AM
A random thought just breezed through while I was collecting bullets to take out to the shop for filing. That is...filing flats for hardness testing, so there is a good surface for the indentor to leave a dimple.

If a guy had a spare mould block half, constructed to mate up with one of his regular moulds, but having no cavity cut...it would produce 'half of a bullet' when used with the 'normal' half of the bullet mould.

Instant lengthwise 'flat face' for hardness testing, and you wouldn't be making the impression on either the nose or base...but in the middle of the bullet's body.

Hmmm...

CM

I must be missing something here....For years I always get a Lee 44 200gRNFP up to temperature when I'm casting other designs that don't have a flat spot. If I wanna know the hardness at any time, I just test the Lee "sample boolits".

sqlbullet
08-24-2009, 11:44 AM
So what do you have against 10 seconds with a file?

Lead hardness is affected by working the metal. Filing may therefore impact any hardness attained by heat treatment.

kelbro
08-24-2009, 01:01 PM
Why would you need a bullet mold? Any receptacle with a flat surface would work.

snaggdit
08-24-2009, 02:15 PM
Why would you need a bullet mold? Any receptacle with a flat surface would work.

Yeah, I started thinking after posting and then reading some replies that you wouldn't need to test "the" boolit you are using, just the alloy. Therefore you would not need a flat mold face for each mold, just one testing mold. Someone want to make a square boolit mold for folks with testers?:razz:

montana_charlie
08-24-2009, 02:22 PM
So what do you have against 10 seconds with a file?
Nothing, actually. And, I often use a chisel instead of a file.
What I object to works this way...

I cast a batch of bullets from a 'new' alloy.
I take them into the house and sort them for visual defects, and set those aside.
After at least two weeks, I will test one of those culls for hardness, so I know what the 'new' alloy is like.

I may have a number of culls waiting for BHN testing on the day that I have time to do that. Instead of 'ten seconds with a file', it's a trip out to the shop to prep the flats. Depending on time of day, and other things, a trip to the shop is usually an 'inconvenience' that would be unnecessary if there was an aged bullet with a flat side already available.

Take the side of the mold without the pins, hold a piece of flat stock against it with pliers and pour. You'll have half a bullet. Don't use the sprue plate .
Not a bad idea, actually...if the blank is nice and smooth.
But, I would rather have a 'dedicated half bullet mould' available for making test slugs...even if it was an old nasty one with your blank plate clamped to it.

I must be missing something here....For years I always get a Lee 44 200gRNFP up to temperature when I'm casting other designs that don't have a flat spot. If I wanna know the hardness at any time, I just test the Lee "sample boolits".
Some of us have no use for flat-nosed bullets...so no mould of that style.

Why would you need a bullet mold? Any receptacle with a flat surface would work.
You wouldn't want to just pour a puddle on a flat plate, because you need enough thickness to support all of the indentor pressure.

Pouring into ingot moulds doesn't work (for me) for two reasons.
- The surface is so grainy, you still need to prep a flat spot for testing.
- An ingot is not guaranteed to have the same 'quality' as a properly cast bullet.

And, I like bullets for testing because Lee sent this neat little V-block for holding them on the ram.

Some thread participants see usefulness in the 'blank block', and some don't.
If you recall, I never suggested it is a good plan...I just described a random thought.

CM

Edubya
08-24-2009, 02:27 PM
I must be missing something here....For years I always get a Lee 44 200gRNFP up to temperature when I'm casting other designs that don't have a flat spot. If I wanna know the hardness at any time, I just test the Lee "sample boolits".

Geez, why do some people make things so simple?:killingpc

Dale53
08-24-2009, 02:50 PM
I"m not even going to comment:groner:

Dale53

qajaq59
08-24-2009, 03:47 PM
I"m not even going to comment:groner:

Dale53

Ahhhh, go ahead.:bigsmyl2:

largom
08-24-2009, 11:35 PM
When casting any Cal. boolits I always cast a half dozen 45-70 boolits for hardness testing. Within an hour of casting I put the 45-70's in my mill vice and mill a nice flat on one side. This gives me 2 or 3 spots to test on each boolit. I air cool my boolits therefore the cut flats will age harden same as my shooting boolits. I keep a log sheet for each casting period and test hardness on the samples every week until I get stable readings.
Larry

Marlin Hunter
08-25-2009, 01:47 AM
So what do you have against 10 seconds with a file?

That a good idea