Small shining flecks from my soft cast bullet on cleaning patch. Leading. Right?

[Tallbald]

It's been a wonderful adventure learning to cast with help from the extremely nice people here. To briefly recap. I'm loading Trail Boss light loads below 1000 FPS. The only alloy I had at the time I began casting was pure lead with 2% tin by weight estimate from solder. I had no COWW. Figuring that I had no evidence (I recognized) of leading when shooting pure lead balls with heavy Triple Seven loads in my Ruger Old Army, I hoped the soft newly cast slugs with Trail Boss would not lead either in my Ruger 77/357.
Trying the three experimental loads, I shot 1 inch groups with the heavier Trail Boss loads of the three. Cleaned my barrel last night with Breakfree CLP, and found a pretty fair amount of very tiny reflective flecks on the cleaning patches. I've not before known of leading in my barrels so I'm only guessing that leading is what's happening. I'm learning a lot of new-to-me things as I go with this casting hobby, so please humor me.
I'm considering now remelting the unloaded remainder of that first batch and alloying them since a very kind and generous fellow on the forum here took pity on my plight. At his own expense, declining my offer to pay him for product and postage or to return to him some of my pure stash, he sent me metals with which to make myself harder alloy. He requested only that I pass along the kindness when an opportunity to help another arose. I don't know if he wants himself identified so I shall not do so.
Does it indeed sound like leading I'm finding? I don't really mind recasting the ones I made if leading is occurring. It was quite a learning experience to make them in the first place.
Thanks for thoughts. Don.

[ohland]

Plain base? Diameter is a little small, or the boolit is too soft for the pressures / velocity.

[Rattlesnake Charlie]

If it doesn't build up and cause a problem, why worry about it? I've had this before, and no build-up occurred.

[Tallbald]

It's a flat base. Lee 358-125 RF. Sized to .358, but I confess I haven't slugged the bore of my Ruger 77/357. I hope it's a softness issue rather than diameter, since the mold is what it is, and the sizing die is .358. Much cheaper and easier to cast harder bullets. I was using almost ten percent below max load for the bullet weight and type Don

[runfiverun]

the trail boss is over pressuring your 50-1 alloy.
wait till you try it in your 9mm.

[243winxb]

What lube are you using? If accuracy goes away, you have leading. Ruger 77 is a rifle, thats new to me. That explains the 1" groups.

[altheating]

I also get the flakes on the patch when I clean, but I noticed they are only on the chamber end. I think the flakes are caused by the crimp scraping small fragments of lead. Anyway it does not affect accuracy at all in my rifle. I'm loading NOE 360-180's cast from WC WW, 8.5 gr 10b101 for 1550 fps. Boolits are sized to .359. I get the flakes with 357 and 38 special brass. As long as it isn't smearing lead down the barrel, keep shooting it with the loads You currently are using.

[Tallbald]

Good food for thought here in all the comments. Thank you. I use the straight liquid Alox that came with my Lee .358 sizing die. Folks here have helped me understand the Alox also, and again I'm grateful.
As I explained, a gentleman here kindly shared some of his alloy component stash with me, and it's best I think for me to be consistent with materials while I'm learning the skills of casting. I learned a lot while casting the first batch of slugs last week from the 98% lead/2% tin mix I had. Pouring technique, correct holding of the mold, proper mold preparation and timing for slug cooling all were learned in a basic way. I know that better results would have come from the accepted wheel weight alloy though. I'm going to melt down and reuse the remaining 200 or so slugs in a correct smokeless cartridge alloy mixture. I need to research here to see the correct weight ratios of WW to pure lead. In the meantime, I'll use up the light Trail Boss loads (about 100 left) in my Ruger SP101 for fun practice. I do wondr though if the harder WW/pure lead alloy I decide on after looking it up here will change the wonderful 1 inch at 50 yard groups I was shooting with the softer slug loads. I sure hope not.
I'll keep posting about my adventures here, and other pertinent events in my journey to casting proficiency. Don.

[454PB]

Did you actually measure the diameter of the boolits as cast? An alloy that has no antimony will produce a smaller diameter.

[Bigslug]

I know that better results would have come from the accepted wheel weight alloy though. I'm going to melt down and reuse the remaining 200 or so slugs in a correct smokeless cartridge alloy mixture. I need to research here to see the correct weight ratios of WW to pure lead. . . I do wondr though if the harder WW/pure lead alloy I decide on after looking it up here will change the wonderful 1 inch at 50 yard groups I was shooting with the softer slug loads. I sure hope not.

50% lead / 50% wheel weight is a pretty common mix. I'd be inclined to just use the wheel weights straight, or maybe add 2% tin. As .454PB say, harder alloys will give you slightly larger diameters.

Assuming you're sized for a good bore fit, your accuracy shouldn't suffer, and may very possibly improve, as your bullets get harder due to less deformation of the bullet's base when the pressure hits it.

If you have a bunch of pure (or nearly so) lead, reclaimed birdshot from your local trap range is your FRIEND! At 4 to 6 percent antimony, it's a great ingredient for making your own "wheel weights" in the wheel weight free world we seem to be headed to. Throw in some tin and you can easily arrive at the @2-3% tin, 3% antimony, @0.5-1% arsenic mix that is commonly know as Wheel Weight +2% tin that can be used for darn near everything if the proper heat treat hardening is used for higher velocity apps.

[1Shirt]

Probably to small!
1Shirt!

[GRid.1569]

IIRC has it not been stated before that the chamber of a Ruger 77/357 has a "sharp" edge at the start of the rifling? could that be shaving a little lead each time its shot?... just a thought...

[KAF]

Some powders will leave small amounts of carbon in a bore. When running a patch through them it leaves small shiny flecks that LOOKS like leading. IF the flecks smear, using finger pressure, to nothing it is carbon, if not, leading.

[Tallbald]

Thank you all for your suggestions. I've learned more here about serious shooting issues than I have in many years of casual reading of periodicals and such. Don