Help with cream of wheat load

[Bob58]

I have been shooting 4 grains of Win 231 behind a 122 grain Leadhead cast bullet in my 9 mm Walther PPQ, and have been getting a fair amount of leading with this load.

I read on this forum about the use of Cream of Wheat (COW) to prevent, and even remove, leading from cast bullets, so I thought I'd give it a try. I made a couple of dippers for measuring the cream of wheat, by cutting (shortening the OAL) on an empty .22 RF case, and wrapping a wire around the base of the cut case for use as a handle. By experiment, I came up with a length that measured out 1.6 g of Cream of Wheat, to dump on top of the powder in the 9mm case prior to seating the bullet. This easily covers all of the exposed powder, and appears to bring the powder column / COW column about level with where the base of the bullet would be when seated. I loaded ten rounds with COW, reducing the 4 g charge of Win 231 to 3.6 grains to compensate for reduced case volume due to the presence of the COW.

Earlier this afternoon, I fired 60 rounds of the 4 g Win 231 / 122 g Leadhead bullet (no COW), chronographing each of these rounds as they were fired. Mean velocity was 1047 fps, with a low of 1014 and a high of 1069 fps.

I then fired all 10 of the 3.6 g Win 231 / 1.6 g COW / 122 g Leadhead, chronographing these also. Mean velocity was 987 fps, with a low of 961 and a high of 1021 fps.

I then came home and cleaned the barrel. Leading appeared to be unchanged from what I would have expected with firing 60 rounds of the 4 g Win 231 / 122 g Leadhead load combination. Based on what I had read previously, I expected there to be no leading, or at least, reduced leading.

Have I misunderstood the COW application in regards to leading?

I'm thinking of repeating the above experiment, but using even more COW, to be certain that the load is compressed, and consequently there would be no (I hope) possibility that the COW will shift down into the powder prior to the rounds being fired. Perhaps this "shifting" is what occured this afternoon, and prevented the COW from performing as I had expected. I drive over some pretty rough country roads to reach the place where I can safely shoot.

Thanks for any help offered. If I've done something really dumb, you have my permission to laugh. I'd just like to know what it is, so that I can make the necessary corrections!

Thanks,
Bob58

[mpmarty]

To stop all leading in that 9mm replace all powder with cream of wheat.
Sorry, couldn't resist.

Normally COW isn't needed in pistol loadings. Lead is probably caused by too small a boolit or loading anomalies.

[runfiverun]

a 356 boolit riding the lands instead of filling the 358 grooves will lead the bbl.
you need the cow to form a plug behind the boolit to fill the bbl up, if it's just stringing along in the bbl it won't work.
i'm not a huge fan of cow filler but since you are doing it i'd up the cow a little and try again.
do a small test of upping it .10 grn at a time and make small samples.
if it will work in this situation you'll find the spot.
it shouldn't take too many shots to clean any previous leading out.
i done a test one time with a known undersized too hard boolit and a fitted proper boolit.
i could see diminished leading in the bbl in 6 shots and could see it moving down the bbl with sucsessive cylinders full till it was gone.

[dverna]

There was some testing done a few years ago with filler in a .45 Colt. It showed that pressures went up dramatically over the course of a number of months.

The 9mm is already a high pressure round. If there is achance your loads will be stored for months/years you may want to ditch the COW.

You can get a 9mm to shoot without leading. Adding another step that slows down the process and may cause a problem seems like a poor solution.

[GabbyM]

“Leadhead cast bullet“ would be a commercial cast bullet I assume?
Not to knock them but for reasons of necessity most commercial cast bullets are lubed with a hard wax lube. To call it lube is a stretch since wax is a marginal lube.

If you have a bunch of these hard lubed bullets try some Lee liquid allox lube to tumble lube them before loading. In this way you’ll have at least a minimal lube source. You could also need a larger diameter bullet.

Horrendous leading with commercial cast bullets is what started me casting my own years ago.