TargetTalk

I've seen many post on loads, leading problems, accuracy and would like to share some infomation I think some know but not everyone.

I've casted my own 45 bullets for lets just say a long time and in the beginning I used wheel weights with good results. Then I got caught up in the hard cast thinking and started having problems with leading and accuracy. To make a long story short, I went back to a softer aloy and life is good again.

I notice a lot of power puff loads in this forum and if you are using hard cast bullets you might be having problems. The hardness of the bullet is related more to pressure the load creates than the speed. My 50 yard load is 4.2 of Bul with a 200 gr head and the pressure is so low most charts don't list it. I believe it is around 11,000 psi but don't quote me.

From what I have read and again don't quote me check for your selves. You actualy need a softer aloy at lower pressures for the best results.

10,000 psi 6 - 12 BNH (Wheel weights)
16,000 psi 8 - 14 BNH
20,000 psi 10 - 16 BNH

I've seen a lot of hard cast bullets out there that list hardness of around 15. (They cast a lot easer) One of the swage bullets you folks talk about has a BNH of 8 - 10.

Something to think about.

I tend to agree, but I am not as sure that hardness or softness, and the slower bullet speed are the only factors. A bullseye gunsmith told me that one of the problems is tin, as an additive.

He said it makes a very pretty shiny bullet but causes a lot of leading.

Nope,
Bullet hardness is not a factor in leading, bullet fit is. Bullets should be cast .001 over bore diameter. Gases escaping around a loose fit bullet will be the premier culprit in leading. Since you are not using blackpowder, which usually will bump a bullet to fit the groove, powders like Bullseye and N-310 in a light load will not seal the bore by blowing out the base of a bullet to fit the bore.
Fire a bunch of swaged 38 Special bullets in a 357 revolver and pretty soon your 357 bullets will not chamber in the gun. There will be a ring of lead that formed right where the 38 case ends. The reason is the 38 Special sits back from the forcing cone and gas erosion leads the leade of the chamber. In fact hardcast bullets will lead the leade less.
For best accuracy, slug your barrel and call up a custom mold maker like Veral Smith at LBT bullets, or Ron Applegate. You give him your lead hardness and recipe for the lead and barrel size. He will cut you a mold that mikes out .002 over your bore with your lead. Then you size the bullet .001 and you will have a bullet with minimum distortion from sizing and a perfect fit in your barrel. Minimal leading and the best possible accuracy. Sorry for the length
Chris

So what causes leading near the muzzle? I shoot swaged lead 148 gr HBWC over 2.7 gr Bullseye, a pretty standard load for a S&W Model 52, and there is always some leading just ahead of the chamber and another little bit near the muzzle.

Roger

Hi guys,

Let me first state I'm not an expert at this but only going on what I've heard, read, and experenced.

Isabel, if you can find a cast bullet on the market without tin in it let the people know. I don't know of any. You can get swaged that are pure lead.

Levergun, all I changed was the hardness of the heads that I casted and it worked for me. The reason I changed was because of articals I read.

Randam, again, from what I have read and it makes sence is leading at the end of the barrel is caused when the lube runs out. I know some swaged 38s I tried just had some sort of coating on them and I never had much luck with them.

We could get into pressure curves and what not but in the long run most want to know what load, head others are using with good results. The reason I started this is from what I've read and then tried for myself.

A formula that has proven itself to me in years of observation and based on the plastic deformation at a given Brinell hardness, 1422 x Brinell hardness = pressure in PSI. This allows the bullet base to upset and obturate, sealing the bore and eliminating gas cutting, a major cause of leading. Cast bullets run from about 16 to 22 Brinell, needing chamber pressures higher to obturate. Example ( 18 Brinell x 1422 = 25596 PSI ). Bullet casters use alloys that are suited for ease of volume casting and general use, not for low pressure target loads, swaged bullets run 10 to 12 Brinell, making them suit target loads in calibers like .32S&W, .38 Spl. Wadcutter and .45 ACP.
Gort

I have found that the softer swaged bullets are perfect for target use, and are the most uniform. Hornady, Speer, Zero, and others are easily available.

The common standard bullet casting alloy is 2% tin, 6% antimony and 92% lead.
Their was a tin free alloy with 5.8% antimony and 0.2% silver, the silver acted as a flux and made the mould fill.
These days I add 1 1/2 sticks of plumbers solder (50/50) to a 10lb pot of lead which gives about 2% tin.
Casting for Blackpowder use pure lead.
Good for all bullet mouldings up to 1100 fps (depending on lube).
Size and lube 0.001 to 0.002 oversize, making sure that your dies do not reduce this diameter on loading.

From what I have been told 2 percent tin is not a huge problem, but more than that may start causing issues. I shoot a cast bullet at the short line, but it is very dull looking. If you get a shiny silver cast bullet, chances are, it is high in tin.
I have not had a leading problem. I shoot a swaged bullet at the long line.

RandomShotz,
Sorry for the late reply. Your 52 barrel could have a tight spot in the middle of the barrel. The bullet would be swaged down and then the bore opens up allowing gas to escape around the bullet. This is not the only answer, but you can test it by slugging the bore. You will feel the constriction in the middle of the barrel.
The other possibility is the bore guide of a crowning tool has chattered in the muzzle end of the barrel. If you have the stomach for it, take a look at the bore past the crown with a 20X stereoscopic microscope. You will see some ugly striations from the chatter across the grooves of the barrel. Happens a lot in Ruger barrels, but one slipup in the production of any barrel will have the same results.
Most barrels shoot best when the tightest constriction is at the crown of a barrel. Poor cleaning practices can wear away this constriction so that the bore more resembles a blunderbuss barrel and will lead accordingly.
Hope this helps
Chris

Many revolvers naturally have a constriction at the thread where they screw into the frame.
The wall there is thin, unless its an ACME thread it will be compressed as its torqued onto the frame.

As I understand it one of the keys to a good revolver is lapping after the barrel has been fitted (assuming its threaded and not pinned).

My Model 16 .32 was terrible for leading, it had also been torqued so tight the grooves on the top of the barrel were twisted at the frame.
Firelapping the thing pretty well cured it.

Had a 32 pardini, (great unit) gave me fits( on the page but not what i would call a group) until I stopped using some commercial cast wadcutters and went with a swagged slug ( hornady). The commercial cast were too hard for the velocity/pressure curve generated. This was indoor line so not hotloads.
45 bit of the same problem inside, went to softer cast problem resolved. hotter load and hardcast outside worked fine. Colt ,gold cup, national match, series 80, modified to remove extra safety linkage of that style.