leading out of the blue

[ctious]

I am shooting a 10mm long slide. I have shot thousands of rounds. No leading. Shooting loads that have never given me an issue before I got leading. The second half of the barrel. That normally would say a lube issue but its the same lube I have been using. Tac 1. I am confused on what could have caused it. I cleaned it out and will be out shooting again this weekend to see if it leads again.

[RobS]

What alloy? When did you shoot the boolits regards to time after casting? When did you size/reload the boolits this time around vs the other times? age hardened vs not as age hardened as in WW alloyed boolits (boolit swage). Did you use the same reloading dies/reloading process?
Did you shoot jacketed bullets from the bore? and then the cast?

Are these the same loads as before i.e. same powder/boolit combo?

More info.?

[ctious]

Same loads as before. Cast at the same time. Shot some the week before no issuesAll sized loaded same everything. No jacketed was shot before. It was about 7 or 8 deg warmer and humid. . But that is the only difference. They are ww 20% pure mix with tin. air cooled.

I am just dumb founded on what triggered it.

[dmize]

I had been shooting handguns with commercial cast bullets for 30 years before I happened across this place.
I have come to the conclusion that a LOT of people worry way too much about "leading" .

[ctious]

I had been shooting handguns with commercial cast bullets for 30 years before I happened across this place.
I have come to the conclusion that a LOT of people worry way too much about "leading" .

When you are shooting 50 and 100 yards a little leading makes a huge difference.

[Oreo]

Interesting. I'm curious to hear the answer too.

A little leading can be cleaned but its important to understand one's loading process. If something changed and goes ignored there could be worse problems as a result. Better to understand and correct the problem now.

[ctious]

Nothing has changed. Same powder lot. Same primer lot. Same lead makeup. Same size. Same lube. Same gun. Lol. The only difference like I said before was humidity and temp a littler higher. But even that sis only a few deg.

[btroj]

If nothing changed then it tells me you were on the verge of leading already.

This is the time to try some experimenting. Try a 50/50 mix of your alloy. Air cool vs water dropped. Heck, even try a very light coat of LLA over the existing bullets already lubed.

This is the fun yet frustrating part of shooting cast. It is all about finding that little piece of the puzzle that matters to that particular gun.

[RobS]

This has happened to me before when I had WW boolits that were sized, lubed, loaded and then shot within a day or so and there was no leading. The same assembled rounds shot a few weeks later leaded.

This is what I concluded:
1. When I pulled a two week old round the boolits were swagged down
2. The day or so boolits loaded up would have had case swage too.
3. However the boolits shot a day or so out were soft enough yet to obturate with the pressures associated to the load I was shooting
4. The two week old ammo's boolits age hardened were hard enough that it made obturation more difficult therefore the leading in the first part of the barrel.

That's my thoughts.

[ctious]

This has happened to me before when I had WW boolits that were sized, lubed, loaded and then shot within a day or so and there was no leading. The same assembled rounds shot a few weeks later leaded.

This is what I concluded:
1. When I pulled a two week old round the boolits were swagged down
2. The day or so boolits loaded up would have had case swage too.
3. However the boolits shot a day or so out were soft enough yet to obturate with the pressures associated to the load I was shooting
4. The two week old ammo's boolits age hardened were hard enough that it made obturation more difficult therefore the leading in the first part of the barrel.

That's my thoughts.


If I had leading in the first part that would add up. But I have it in the second half of the barrel. The throat is clean. And for a good 2in or more clean then turns to hard leading 360deg. All the way out to the end. Acts like a lube fail. But I find it odd that the lube al the sudden failed.

[RobS]

Or the lube did it's job the first part of the barrel and then ran out due to the gas blow by. Could work both ways I suppose. Have you pulled a boolit to see if it's the diameter you intended it to be?

[williamwaco]

I suspect the bullets were swaged down either during seating or crimping.

Re-read RobS

[ctious]

I suspect the bullets were swaged down either during seating or crimping.

Re-read RobS

It would have had to happen in the past week sitting in the ammo box. Cause last week the same loads all shot fine. I guess it could have had some shrinkage. I even have a m die that opens the brass to .3995. So u would have thought that should be enough to avoid swaging in the case.

[RobS]

The thing about expander dies is they need to expand the case the length of the boolit that is seated into the case (all the way to the base). This does not mean the length of the expander but the actual part of the brass that is expanded by the spud.

[ole 5 hole group]

In one of my 1911's in 45 ACP I occasionally get a lead buildup using 0.451" cast - great accuracy but I sometimes experienced a heavy lead build-up. With 0.452" cast I've never experienced heavy lead build-up and the accuracy is the same.

[44man]

I have to go with lube failure under conditions. I never used that lube so not sure. Nothing else would have changed enough.

[Larry Gibson]

I have to go with lube failure under conditions. I never used that lube so not sure. Nothing else would have changed enough.

+1. Agree, that's what it sounds like to me also.

Larry Gibson

[ctious]

So I shot those same rounds out of my carbine with e 16 in barrel. No leading. Lol.

I am going to check the pistol barrel over by slugging it and see if maybe it just wore out to a dia larger than the boolits. May have to open up the sizer a little to make it good again.

[HeavyMetal]

I'm buying into the idea your lube load combo was on the edge of leading and the temp change put it over the top.

Unless you fired the rounds in the 16 within minutes of shooting the same lot of reloads in the longslide you missed the conditions causing the problem.

I to have never used that lube but I have shot enough rounds to know a lube failure when I read about it: if leading starts in mid barrel the lube has failed!

[at_liberty]

Does the lube brew (with which I am not familiar)need to be shaken or stirred before use? You could get variable coverage.

[ctious]

It is a lube failure. Shot it at night when temps were in the 70s and shot clean. Then in the day again when its 90s. Lead again. It seems to have a fail point in the upper 80s for my longslide. And in the carbine it still holds well into the 90s.