Goldilocks and BHN issues :(

[mistermog]

So, I am casting 45 and 9mm using wheel weights.

At first when I water dropped them they tested out to 28 BHN (lee tester) and I was getting leading.

I tried air cooling them and they are giving me about 11.8 BHN.

Using the math I saw somewhere, I need about 18 BHN for 26.5k psi chamber pressure, so both of my methods are too hard or too soft. (1440*BHN=psi)

What would happen if I air cooled, then a couple days later toasted them in the oven for a while and water cooled them after that?

I calipered my bore and it came up to .356 and I am sizing to .357 and lubing with some of the white label guy's xlox 2500+ lube.

Ideas? It looks like I spray painted the inside of the barrel with gray spraypaint.

[MarcusT]

You might want to pull a loaded round down to make sure the cases aren't sizing your bullets to a smaller size.

[btroj]

Did you shoot the air cooled bullets?

Assume nothing. Many times something that shouldn't, that can't possibly work, does! Go test them out.

As forth bore condition, was it speck and slivers of lead or just a dull grey appearance? That dull, grat appearance is commonly called antimony wash, it isn't really leading. That is something that doesn't often affect a thing.

How did the load shoot?

[mistermog]

I've pulled them and there was no squishing by the case that I noticed, and yes I shot both.

With the its a dull gray coat over the whole barrel pretty much with lots of smears of lead in the grooves.

well, I'm having trigger pull issues and didn't have a bench handy but not too badly.

[runfiverun]

i can assure you, you do not need 18 bhn.
i use 18 for loads in the 45k range.
you have something else going on such as copper in the bbl,need another .001 in boolit diameter.
a tight spot or throat issues.

[geargnasher]

i can assure you, you do not need 18 bhn.
i use 18 for loads in the 45k range.
you have something else going on such as copper in the bbl,need another .001 in boolit diameter.
a tight spot or throat issues.

MmmHmmm. "Scraper throat" syndrome. Prolly needs some tin in that mix to control the antimony wash, too.

Gear

[mistermog]

That is possible, I need to load up a few more and make sure the barrel is cleaned well before i take them out. I don't know if it was spotless this last time out.

I also took out a 1911 with boolits made from the same aircooled mix and it does not have anything in the barrel whatsoever after 40 rounds, but they are less pressure than 9mm.

OK I will keep at it, I wont throw my guns in the river just yet. :)

[btroj]

I still want to know how the original 9 mm bullets shot. If they hit where aimed over a string of 100 or so rounds I don't care what the barrel looks like when done.

Stop looking in your barrel and start looking at the target. If the target is good, ignore the barrel. Only look at the barrel when the target says something is amiss.

In short, don't go looking for problems. What works, works. Dont worry if it fits the "parameters" for acceptable pressure, etc- if it works, go shoot it.

[mistermog]

Yes they hit around 3" group somewhere abouts at 20 feet. (not great i know but thats my trigger control). :)

[Bret4207]

So, I am casting 45 and 9mm using wheel weights.

At first when I water dropped them they tested out to 28 BHN (lee tester) and I was getting leading. With straight WW?!! Either your tester is junk or there is some operator error or you have a large amount of zinc in your mix. Using old WW with lots of Sn and SB I had to juice my alloy quite a bit to get past 25-26 Bhn.

I tried air cooling them and they are giving me about 11.8 BHN.

Using the math I saw somewhere, I need about 18 BHN for 26.5k psi chamber pressure, so both of my methods are too hard or too soft. (1440*BHN=psi) Do yourself a favor and forget Lee's formula. It may be accurate for giving you the borderline for "slump" but it doesn't tell you squat about what it takes to get a fitted boolit that will hold the rifling. It's another supposedly easy answer to a very complex issue that has lead many people to come to incorrect conclusions.

What would happen if I air cooled, then a couple days later toasted them in the oven for a while and water cooled them after that? You'd spend a lot of time and effort on something you may not need to do.

I calipered my bore and it came up to .356 and I am sizing to .357 and lubing with some of the white label guy's xlox 2500+ lube.

Ideas? It looks like I spray painted the inside of the barrel with gray spraypaint.

Clean the barrel first, 4/0 steel wool and little solvent will do it. Start at square one with your AC WW and low ball loads. See what the gun says. I think you might be better off a thou larger. The lube should be fine. Read up on FIT here. Fit is king with cast. Bhn is a tool in fit, but it's down the list a ways.

[mistermog]

Yeah I read measure the barrel and then size .001 over that, which is what I was doing. I was thinking once I have that and lube, that hardness was my other source of issues. Hmm. I've only been doing this a few months and still learning as I go. :)

All of this is greatly appreciated.

[Wayne Smith]

Did you size over the bore (small diameter) or groove (large diameter)? You need to be .001" to .002" over the groove.

[mistermog]

I used the calipers and got the biggest measurement of the grooves. .001 over that.

[H.Callahan]

I used the calipers and got the biggest measurement of the grooves. .001 over that.
Calipers is probably not the best method for measuring grooves. You probably need to actually slug the barrel and measure the grooves with a micrometer. I suspect you have some error in measurement of the grooves.

[1Shirt]

I really question you getting water dropped ww's to 28 BH. The hardest I have ever seen (via my Cabin Tree tester) was between 19-22 Bh. AND-----pay attention to the recommendations given above, with emphasis on those by Bret!
1Shirt!:coffee:

[Larry Gibson]

Forget the math, forget WQing them. Add 2% tin to the COWWs and air cool the bullets and age them for 7 - 10 days. The BHN should be 14 - 17 with 16 - 17 the most common if the WWs were a good batch with proper lead, tin and antimony %s.

2500+ lube is made for HV loads. I suggest a different lube such as BAC or the 50/50 Alox Lars sells.

Larry Gibson

[mistermog]

I talked with them and they said theyve used it down to 400 fps on a .38 spl load, so they believe it should fine. i was kidna thinking that too but they are saying probably not.

I use the same aircooled bullets in a 1911 and not one itty bit of leading whatsoever.

[Bret4207]

Just so you get on the right track early, leading isn't caused by "soft" lead and fixed by going harder. Leading is basically the result of poor fit. The exceptions to that rule would be really rough barrels that actually abrade the lead off the boolit, may a coupe other things. Fit is more than just going a couple thou over groove and hoping for the best. I don't mean to be cryptic, it's just that all the info is in the stickies and in the archives and involves static and dynamic fit. Bhn is part of dynamic fit. So is pressure and burn rates and a whole bunch of stuff I'm not even close to qualified to guess at. Suffice it to say that "Goldilocks" would find a lot more than just 3 bowels on the table and more than one would be just right! It would all depend on how she held the spoon, what shape the spoon was, how fast she put the spoon into the porridge, how fast she lifted it out, if it was runny porridge or stiff porridge, a big round spoon or a small narrow one......you get the idea.

[mistermog]

I've been pouring over the stickies about sizing and hardness and fit and leading all over the place for a while now. I don't have some elaborate setup to keep measuring and trying things, I just have a few ingots made from wheel weights and a lee 4-20 pot and some molds.

I dont understand the 'art' in this, being an engineer youd think if it works, it will always work.
Wheres the numbers and facts, all this maybe stuff is confusing me. :)

I know powder burn rate might play a factor in this somewhere, but probably way down low. As far as that, I don't knwo anything else about that topic.

I'm just trying to find out what I don't know in what order they are important at. I am trying to cover a base at a time and I don't think thats how this is going to work.

[mistermog]

Actually, just reading a few more things, I did have a problem with the brass swaging bullets down to .355 when I had the factory crimp die cranked down a bit too tight. When I made up these loads I checked it after I pulled but I wonder if I only checked the top part of the driving bands and not the base as well enough as I should have.

Maybe using a .357 instead of a .356 with lee's standard size of dies might be hindering a few items in my list.

[mistermog]

Ah HA! I just loaded up a dummy round and checked.

I am using Lee's 120gr truncated cone mold that has the single lube groove. The area above the groove is 357 as expected, but the bottom half of the bottom area is 355!

shenanigans!

[462]

Step number one:
Seat the boolit.

Step number two:
Crimp the boolit using a conventional roll crimp die.

Step number three:
Pull a boolit and measure the base. It should be the same dimension as it was prior to seating and crimping.

[mistermog]

I can tell you right now it is not. I just ran it through the seating die and it smooshes it down at the base of the boolit. I put it in my caliper lengthwise and you can actually see it tapering down toward the base.

[Bret4207]

I've been pouring over the stickies about sizing and hardness and fit and leading all over the place for a while now. I don't have some elaborate setup to keep measuring and trying things, I just have a few ingots made from wheel weights and a lee 4-20 pot and some molds.

I dont understand the 'art' in this, being an engineer youd think if it works, it will always work.
Wheres the numbers and facts, all this maybe stuff is confusing me. :)

I know powder burn rate might play a factor in this somewhere, but probably way down low. As far as that, I don't knwo anything else about that topic.

I'm just trying to find out what I don't know in what order they are important at. I am trying to cover a base at a time and I don't think thats how this is going to work.

Be nice if that was the case, eh? The problem is variations- between guns, between brass, between your alloy and mine, between your old batch of alloy and the new one, the old lot of powder and the new one, atmospheric pressure, eroding throats over time, wear in a sizer die or loading die over time, between your mould and mine and 100 other moulds, in build up in the barrel, in lots of lube.......lots of variations. So we start with the basic part- fit. You know you have to seal the barrel and it's betters if the throat is also sealed. For step one there are 2 ways to do this, 1- Use a boolit large enough to seal the throat, 2- depend on "obturation" to mash your boolit into putty and hope it fits and seals the throat. You can probably tell I'm not crazy about the 2nd method. If you can start with that with low to midrange loads using what ever alloy you want, you are starting off right. That's basically your static fit. Of course alignment, seater "squish" (as you have found) and a few other things can mess with that. Then you go over to the dynamic end of fit- what happens when you pull the trigger? That's where it get's tricker and we get into things like burn rate. Burn rate isn't down low on the the list, it's up high! Peak pressure/time is the big bad boy as I understand it. You pop a boolit out the muzzle at, say, 1500 fps. Now it could have gotten there with a nice gentle shove or it could have gotten there by being slammed with a bat or hammer. How it got going 1500 fps matters, it's part of that formula you were talking about, but not all of it.

Start off by solving your static fit issue and the rest will follow. You won't need an elaborate setup, just a set of eyes, a micrometer, a note book and an open mind.

[462]

"I just ran it through the seating die and it smooshes it down at the base of the boolit."

I experienced the same problem till I got rid of all the Lee seating dies.

[mistermog]

I took a look at the stickies and this time understood what Jailer meant when he used his 38 expander in his 9mm expanding die.

I just ordered a slightly longer plug myself and hoping to try this out. I just wonder about the whole neck tension thing to keep from getting setback, but using larger bullets I don't tihnk it will be an issue.

[runfiverun]

you are trading size for size.
2-3 thou should be enough to prevent setback.
even hard squeezed jaxketed suffer from setback after a few chamberings.
so make up a dummy and chamber it a few times and measure the oal.
they only have to chamber once [twice maybe]