Leading problem has me curious

[qajaq59]

I am using some purchased cast bullets in my Winchester 30-30. They are sized to .310 cal and frankly they shoot real well and I have had absolutely no leading with them even though they are not gas checked. Then just for laughs I tried them in a Swiss K31 at about the same velocities and I am finding "flakes" of lead at the muzzle and in the barrel when I clean it. Now I'm not talking about some dullish lead spot inside the barrel. These are loose flakes that are roughly 1/64 inch in diameter, and I have never seen that before.
Anyone want to venture a guess as to why they are coming apart. I really have no need to shoot then in the Swiss rifle, but I have to admit I'm curious as to what is going on.
Qajaq59

[Nobade]

May be that they're a little too big for the Swiss rifle. Not often, but sometimes cast bullets will shoot better when they're smaller. I see it with my .223 with many different bullets and loads. Those K31s have pretty tight bores, and mine at least works best with bullets no bigger than .309. If you have a .308 or .309 die you might try running some through that and trying again. Might try putting some tumble lube on them as well to see what that does. BTW, those K31s make wonderful cast bullet rifles! Mine is incredibly accurate with the Lee c-312-155-2R sized to .3085 over pretty much any powder I want to use at 2000 fps. Best with IMR 4895 and Varget.

[qajaq59]

I wasn't going to pursue using the cast in the K31, but if you are having good luck with them maybe I should. I do like shooting cast bullets and I go thru 50 or so a week in the 30-30.

However I used a weak load from my .308 manual for the powder load because I can't find a source for loading cast in the K31. And to be truthful I'm not all that comfortable with making up loads. I've loaded forever, but always straight out of a manual.

Do you have a source for the loads or are you winging it as well?

Qajaq