Leading problem, too soft BHN?

[Jlamont2020]

I've been shooting my MiHec 359-125 HPs in front of 3.8gr on HP-38 at 1.085" OAL for a little bit now. The speed is averaging ~1040fps and I seem to be getting terrible leading in my pistols.

I'm casting 20:1 air-cooled which should be a BHN of 12. I've read tons of data of people pushing 20:1 up to 1500fps without leading, so I'm confused on what I'm doin' wrong. My smallest pistol slugged at .355, the largest at .359, and the carbine at .359. I'm sizing them down to .358 so in theory, they should be fine. I cast pure lead bullets for my air rifle so I prefer to make my own alloys over mixing with WW, since I buy pure lead anyways. Though I'm at a loss at why I'm leading so badly. The load is mid-range, the speed is not overly fast or slow, the BHN is on the softer side (but not overly so for the speed), and my boolits are reasonably sized for the barrels.

I'm thinkin' I'm going to try water quenching the next 300-400 boolits to increase the BHN slightly. From what I've read it should go to about 15 considering there's no antimony in a 20:1 alloy.

I know eventually playing with all the factors I'll figure out the cause and correct it, though I'll take suggestions. That being said at the moment I'm not looking to change to a WW alloy.

This is from my father's Kahr CW9 after about 300rds. (I know, terrible photo)

[Jlamont2020]

Also, this particular batch had been aged about 2 months (usually it's closer to about 3 weeks)

[Yodogsandman]

!. Non antimonial bullets won't age harden or heat treat.

2. 20:1 is only about 8 BHN

3. You can't water quench bullets that don't have antimony in them and expect them to increase BHN.

4. 9MM is a high pressure round, those shooting to 1500FPS with 20:1 alloy are using low pressure rounds, typically black powder.

5. Each pistol or rifle needs to be sized specifically for it's own chamber.

Check this site for some great info...

http://www.lasc.us/ArticleIndex.htm

[RobS]

Good info. above.

Another issue that occurs is that the 9MM case is a short, strong case. A soft boolit seated in 9MM cases can often time swage down to a smaller diameter than what it was prior to being loaded.

I would measure a boolit before, load a dummy round, then pull a boolit and measure it. I bet the base of your boolit has been swaged down by the case.

As been stated a .358 boolit in a .359 barrel can cause leading and also inaccuracy.

[RobS]

Velocity is not the determining factor to what the hardness of a boolit should/could be for accuracy and a clean (no leading) barrel. Considerations to pressure, barrel twist rate, chamber throat, barrel condition, powder selection and reloading practices are a few other variables to successfully shooting cast boolits.

[Petrol & Powder]

Posts #3 & #4 are spot on and I'll add my $0.02.
9mm gives me fits with cast bullets when I try to cast & load for more than one gun. As you've found out, 9mm barrel diameters are all over the map. I can get cast bullets to work beautifully in ONE pistol when I match the load to that one gun but when I add another gun to the line up I have problems.
Fit is critical and damn hard to achieve when the barrels are not a uniform diameter.

[Jlamont2020]

Good information so far, but no real recommendations.

As much as I dont want to keep 2 different alloys, is using a different alloy thw best thing to do. I originally settled on 20:1 as it was a recommended Elmer Keith alloy for cast HPs in .357, and .38.

Well the sizing issue makes sense for the .359 carbine (and I figured that may happen since it's undersized) but for the .355 pistols .358 shouldn't be a size issue right? I'm trying to have semi-reliable expansion with HPs. So what was be a good recommendation, resize to .357 at a 50% WW 50% Pb? I love the expansion I get, but the constant cleaning is a bit annoying.

[bangerjim]

Yes, you are assuming several things that are probably leading you astray.


And...........you NEED to seriously consider switching to a COWW Sb style alloy mix! You can easily make you own, now that WW's are becoming hard to find. I have been doing it for over 2 years after most WW's are now Zn and Fe.

Read and re-read Yodog's post above. Sums it up well. I "shoot" for ~0.002 over slugged bore size.

I would NEVER attempt to do what you are attempting without knowing the bore of each gun, using anything lower than 12 Bhn (tested, not guessed at by %) and........I powder coat everything. That does let you shoot softer without smoke and leading. Use PC (NOT quenching) on your non-Sb mixes. I cast 9-12 for all my subsonic rounds + PC.

Good luck!

bangerjim

[bangerjim]

Good information so far, but no real recommendations.

As much as I dont want to keep 2 different alloys, is using a different alloy thw best thing to do. I originally settled on 20:1 as it was a recommended Elmer Keith alloy for cast HPs in .357, and .38.

Well the sizing issue makes sense for the .359 carbine (and I figured that may happen since it's undersized) but for the .355 pistols .358 shouldn't be a size issue right? I'm trying to have semi-reliable expansion with HPs. So what was be a good recommendation, resize to .357 at a 50% WW 50% Pb? I love the expansion I get, but the constant cleaning is a bit annoying.

You've got some very good recommendations!

If you want to eliminate leading (with proper sized boolits to your bore) use PC. Over the past 2+ years I and many other on here have developed the PC processes to a science. I and many hundreds (if not thousands) have eliminated leading 100% and still shoot softer alloys.

bangerjim

[Love Life]

You can always solve your problem with this: http://www.grafs.com/retail/catalog/...roductId/13838

I would slug your father's gun's barrel and size to that barrel. I would also switch to WW alloy or something similar and water drop. Take a look at your lube as well, as softer lubes have always worked better for me in the 9mm than the hard as crayon lubes. Then there is the real possibility that your bullets are being swaged by your brass.

Many things going wrong here and you need to eliminate one variable at a time. I would utilize the scientific method.

[Petrol & Powder]

What do you mean, "...no real recommendations"?

1. slug your barrels and size your bullets to each gun accordingly
2. it is very possible that the casing is sizing the bullet down. Disassemble a completed round and measure the bullet diameter. I'd be willing to bet the bullet is smaller than you think.
3. After you've solved the bullet diameter issue, look at going to a softer lube

Love Life is right on the money, eliminate one variable at a time.

[Jlamont2020]

"No real recommendations" was a poor way to conveying my thoughts. I got a lot of information quickly show ing me what was wrong, but was looking more for a guide of what I should try out first to correct the problem. (Which some people have now posted)

I've slugged all my barrels (and my father's) before I started casting I know there was no "do all" but I attempted (failed) at trying to resize cast to .358 in hopes of satisfying the .355 and .359 barrels I use.

And yes, I just measured some of my pulled boolits and they seem to average .354 after being seated.

Looks like despite my desire for simplicity, I'm going to have to add extra steps to my powder loads. (Either powder coating or alloying), as well as size 2 different diameters for the .355 barrels and the .359 barrels.

[williamwaco]

Your alloy is plenty hard.
You do not need two alloys.
You may need two different loads.

Reread your post. If you are using .358 bullets in a .359 bore it is not likely to "be fine".

You do not mention your lube. Lube is more critical in the 9mm than any other handgun cartridge I have ever loaded.

The 9mm is the most prone to leading of any handgun cartridge I have ever loaded.
Fit and Lube are the most critical components. MUCH more important than alloy or hardness.

I strive for .002 to .003 over grove diameter. For me, that is .357 to .358.
I cast anything (alloy) I have available from BNH 10 to 13. Occasionally bur rarely BNH 14 to 15.

Fit is CRITICAL. Not your sizing diameter but your diameter when the pin hits the primer.
Pull a bullet from cases of different head stamps.
If you are worried about pulling a bullet from a live round, load a dummy. Load it exactly like your normal procedure but omit primer and powder.
You are very likely to find that some of them are significantly smaller than you thought.
The 9mm cases vary significantly in wall thickness and some will size your bullet down to .349 to .350 during the seating operation.

Oh yes. Did I mention that fit is critical.

The popular hard lubes do not work well in the 9mm ( for me). I like LLA or Lyman 50/50. The custom mixtures mentioned frequently here are excellent. I don't use them because I am too lazy to mix them.

If you have a hard lube you can sometimes get it to work by increasing your powder charge to maximum. I don't recommend that so I just don't use the hard lubes.

The perfect storm for leading is a hard, undersized bullet with a hard lube. ( Don't go there. )

If you are determined to make one load fit all guns. make a load that works with the .359 bore. Then if the overall cartridge diameter is small enough to enter the chambers of the others, it will probably work in the others too. BUT it must fit easily and loosely. Not just crammed in.

[Love Life]

Your bullets are getting swaged down and creating an issue of being to small. I'd start there to ensure your bullet is the correct size when it enters the barrel in the 1st place. Fix that and:


Now that you've established that your bullet is the correct size for your barrel (both as sized, and when leaving the brass) go fire some and see what happens.

Still got leading? No biggie. You've eliminated undersized issues, now you can change one of two things (only one at a time).
A) Lube or
B) Alloy

I'd tray a new lube first. Something soft. I prefer speed green or Lotak hard from the Bullshop.

Load some, and go shoot. Still issues? Well, now try the other thing and repeat.

Somewhere along the line will be your answer.

[RobS]

One other thing a person can do is get an expander plug .001 under the boolit diameter that will expand the case to the depth of the seated round. This is an approach often used in the reloading process when assembling rounds with softer BHN boolits.

[Larry Gibson]

As mentioned; what lube are you using?

Also as mentioned your BHN numbers are too high for 20:1 alloy. Also as mentioned WQing will not harden that alloy.

Larry Gibson

[jonp]

!. Non antimonial bullets won't age harden or heat treat.

2. 20:1 is only about 8 BHN

3. You can't water quench bullets that don't have antimony in them and expect them to increase BHN.

4. 9MM is a high pressure round, those shooting to 1500FPS with 20:1 alloy are using low pressure rounds, typically black powder.

5. Each pistol or rifle needs to be sized specifically for it's own chamber.

Check this site for some great info...

http://www.lasc.us/ArticleIndex.htm

Im getting 10bhn with my 20:1 using a lee hardness tester

[jonp]

Both of my Kahr CW45's have given me such fits ive about abandoned cast in them and switched to plated or jwords.

[Petrol & Powder]

If your pulled bullets measure .354" I'd say there's your problem.

[guncheese]

If your pulled bullets measure .354" I'd say there's your problem.

ding ding
i run pretty soft alloy PC
but if it gets squished it gets squished
a flame cut is a flame cut
i know this doesnt give direct answers, but it does give a heading to plot a course for
https://plus.google.com/u/0/collection/E8BPf
there are 12 or 13 pix in that collection that will show you what is going on