Another 9mm thread
 

I cast up a couple thousand .356 bullets using the Lee 124gr truncated cone tumble lube mold. My COAL is 1.050 inches. I am using WSF powder. I started with 4.4gr, and got a lot of leading. I worked up to 4.8. It seems to have improved, but still leading up. Anyone gimme an idea for max charge with this combo? Its being run thru a Kahr CW9. Thanks in advance.

Did you happen to slug the barrel? You might be a little small at .356 considering what the bore might be. If your bore is at .355 then Im thinking .356 should be ok. If your bore is close to .356 then a .357 might run with a little less leading.

What did the bullets cast at? re-sized to .356?

I got .3535 in the grooves, and .3435 in the lands. I've not slugged a barrel before. I put it in a vice and used a punch to drive the bullet thru. is that typically how it's done? My lead is WW, water quenched. I'm wondering if I should heat treat @ about 475 degrees for an hour.

You slug w/ a dead soft lead bullet that is over size. Lube it w/ case lube or such & drive it thru the bore, chanber first if possible. Measure thehigh poitns, that is groove dia. Add 0.001" for a lead bullet MINIMUM.
Bullet fit is #1 but alloy comes into play as well as bullet lube & the powder you use. Where is the leading? If it's early, then the bullet is too small or too hard for the pressure used. If it's at the end, the bullet lube is failing. If it's all along, then could just be a rough bore or a really small/hard bullet & low pressures.
Drop the water quenching. Clip ww are fine for any sane 9mm load. Quenching makes them so hard, you have to drive them hard to obturate or size tehm larger. Even 0.0005" larger will matter when it comes to leading.

.3535 seems a little small for a 9mm. My understanding is bullet/bore interference should be about .001/.002 so I'd say your not too small.

The issue w/ measureing a cast bullet driven into the lands is spring back. Plus most can not accurately measure below 0.001" w/ calipers, you would need a micrometer to be more accurate.
I am betting you air cool the clip ww, things will get much better. IME, there is little to be gained by super hard bullets @ most handgun pressures. Maybe for max loads, but not where the OP is at. I run clip ww, air cooled, to 1500fps in my 45-70 w/ little leading.

Kahr say's no lead, same as Glock. Just sayin...

The CW9 has a regular rifled barrel. The P9 has polygonal. So therorticaly the CW9 should be fine with lead.

What does "leading" look like?
I'm a FMJ guy.

I agree. Back off on the hardness of the bullets. WSF should be about the perfect powder for what you're doing. I never used it, but I use Unique which is very similar.

I use range scrap which is softer than WW and much softer than water quenched WW and drive 125's at 1150 with Unique all day long and get no leading in my Glock's or Ruger with stock barrels. I do use liquid alox, which may be superior to standard lubing, but I never did any kind of side by side testing. All I know is liquid alox, a soft bullet, and a mid burning powder hasn't leaded on me in 9mm and 40 SW.

I do run my 9mm's bigger. They come out of the mold at 0.357", so that certainly can't hurt.

The first, and easiest thing to do is to try to air cooled bullets and see how they do. Even mix in some clip on WW since they are softer if you have some as a second step if air cooling them doesn't fix it.

If either of those easy possible solutions doesn't do it, let us know and we'll try some more difficult, but not overwhelming, solutions (like using a larger diameter).

As far as slugging a bore, like Fred said, it's easy to do but hard to do accurately. Unless your a machinist who really knows his way around a mic, and maybe you are, trying to read a slug with high and low spots etc is not easy to do right. I could read it four times and get four different numbers.

Basically, I think bore diameter is approached the wrong way. You don't want a bullet exactly 0.001" over bore size and it's hard to get that kind of precision. What you want is a bullet that is bigger than your bore. The easiest way to do that is to use the biggest bullet that will chamber in a loaded round in your gun.

My Glocks and Ruger will chamber 0.358" 38 cal bullets no problem. They shoot great. I've never even field stripped a car much less shot one or loaded cast ammo for it, so I don't know how sloppy their chambers are. But my guess is that a 0.357" bullet will chamber and work fine. Getting your bullets bigger from the mold you have isn't rocket science, but it's a little involved.

I'd just soften the lead up a bit and try that first because I think it will work.

Like this..

This is rather severe barrel leading. There are several pics taken in the album if the link allows you see the others.

http://farm5.staticflickr.com/4022/4...a79712c353.jpg