Leading in my LCP

[Nocturnal Stumblebutt]

So, oddly enough, my LCP seems to have suddenly started leading. I am using the Ideal 358242, 92 grain, cast from water quenched COWW, sized to .358, lubed with Lars BAC, over 2.8 grs of Bullseye. I didn't get any leading when working up the load, but today I put 50 rounds through it and seem to be getting some leading in the corners of the rifling grooves. I have been casting for a while now and this is the first time i've really had leading.

[fecmech]

My LCP slugged .3575 which surprised me a bit. I wonder if Ruger is not intentionally oversizing the groove a bit to hold down pressures on the little guns. I get light leading in mine at .358 but none at all in my Keltec which has a .355 groove.

[Nocturnal Stumblebutt]

That's what I was thinking, I'm getting it in the last half inch of the barrel, which makes me think that the barrel is ever so slightly oversized that I am getting so blow by. Maybe i'll try a few .359.

I should say though that accuracy has been excellent, and a huge improvement over factory loads. I've been practicing my defensive shooting by placing a semi-circle of bowling pins around me at 7-12 yards, and firing quickly I get 5-6 pins for the 7 rounds in the LCP.

[Larry Gibson]

cast from water quenched COWW

COWWs are antimony rich compared to tin content. The antimony is not in good solution with the lead unless more tin is added. Add 2% tin to the COWWs for a much better alloy. Also WQing may exasperated to antimonal crystalization in the lead and you may be actually getting antimonal wash instead of leading. Adding the Tin will also prevent that as the antimony will then go into solution much better into the lead. A much better alloy will be the result and WQing will not be necessary or desired. AC the cast bullets and let age for 7 - 10 days before use.

Nothing else wrong with the sizing, the lube or the load.

Larry Gibson

[cbrick]

Stumblebutt, for an accurate explanation and cure simply re-read post #4. I couldn't have said it any better, add 2% tin to the COWW and forget the water quenching.

Rick

[Nocturnal Stumblebutt]

So, what exactly is antimonial wash? Is it as bad as leading? I'm not saying that I'm ok with it, I still plan to remedy it, I just don't know what it is?

[cbrick]

I've never found it to be nearly as bad as a leaded bore and easier to clean up. I've seen it in the last few inches of the bore and it looks like a grey wash of leading. Think of it as free antimony scrubbing off the boolit. Balancing the Sb with the same percentage of Sn usually fixes it.

For many years now all of my alloy, mostly COWW automatically gets 2% Sn regardless of the load or gun it's for. I have avoided many of the issues commonly discussed in this forum. Larry does the same and often recommends adding 2% tin to help with the posters problem. I couldn't agree more, he is spot on.

Rick