Rookie ?'s; leading?

[klausg]

All-

Thanks again for all of the info on my "Casting for Dummies" thread, I have a few more rookie-type questions. Specifically dealing with leading; not that I have any grossly disgusting problems. Nothing that affects accuracy, (@ least as well as I shoot a handgun), and nothing that a few J-bullets, (I know that is a dirty word around here) won't push out of the bore. However it is enough to be annoying, particularily when I forget to bring a few J-bullets to the range & I'm stuck cleaning all of that out. Is leading a function of velocity, or bullet hardness, or both? Is a gas check necessarry? Is that the end all to the leading problem? As to bullet hardness, and please correct me if I'm wrong; I understand that adding antimony to the mix will harden it. Too much antimony makes brittle bullets. Further, heat-treating will harden a bullet, will it make it brittle? The Lyman handbook has you heating your bullets in a 450 degree oven for an hour & then quenching in room temp water; wouldn't it be easier to drop them straight from the mold into a 5 gal bucket to quench them? One final question as to alloy, does the tin do anything other than make the lead "flow" better? Again thanks for all of your help on my last thread, and thanks in advance for your responses to this one.

-SSG Klaus

[versifier]

Is leading a function of velocity, or bullet hardness, or both?
Factors that affect leading are size relative to groove diameter, relative strength of the alloy with respect to rpm and velocity, and the hardness which has direct bearing on the strength.
Is a gas check necessarry?
Sometimes, but it depends upon what caliber, profile, and what velocity you want to push them at. In general, they can help you get a bit more speed before you start to lead up, most especially in smaller calibers. They can be a big help getting more speed with softer hunting boolits..
Is that the end all to the leading problem?
Not necessarily, as there are many other factors involved..
As to bullet hardness, and please correct me if I'm wrong; I understand that adding antimony to the mix will harden it. Too much antimony makes brittle bullets. Further, heat-treating will harden a bullet, will it make it brittle?
Yes, it both hardens the alloy and makes it more brittle, and BTW add your antimony by adding linotype or ww - don't mess with metalic antimony as it's very toxic.
The Lyman handbook has you heating your bullets in a 450 degree oven for an hour & then quenching in room temp water; wouldn't it be easier to drop them straight from the mold into a 5 gal bucket to quench them?
I think so, and prefer the water drop method, but you will hear different opinions here by those who have great results heat treating.
One final question as to alloy, does the tin do anything other than make the lead "flow" better?
It hardens it a little, but I think its aid in proper fill-out far surpasses this.

[Bass Ackward]

1. Is leading a function of velocity, or bullet hardness, or both?

2. Is a gas check necessarry? 3. Is that the end all to the leading problem? 4. As to bullet hardness, and please correct me if I'm wrong; I understand that adding antimony to the mix will harden it. Too much antimony makes brittle bullets. 5. Further, heat-treating will harden a bullet, will it make it brittle? 6. The Lyman handbook has you heating your bullets in a 450 degree oven for an hour & then quenching in room temp water; wouldn't it be easier to drop them straight from the mold into a 5 gal bucket to quench them? 7. One final question as to alloy, does the tin do anything other than make the lead "flow" better? -SSG Klaus


SSG Klaus,

1. Velocity results from pressure. Pressure is the real enemy. Hardness vs bore condition vs lube quality determines if you lead. Go weak on any one of those and the others must pick up the slack.

2. Yes and No. I have guns that will shoot one load and another will lead with it. GCs give you more fredom by increasing hardness where pressure is strongest. But you can make a GC design fail too if you aren't using your head.

3. See 2. above.

4. You are correct.

5. Depends on what medium you are shooting into. A harder bullet when it starts to obturate can tear off into chuncks. Tin helps ductility. The most ductile situation is one where tin equals antimony content.

6. MAjor subject that has been writtent to death. You need to use the search function and search for both Heat treat and Water Dropped and read.

7. See 5 above.