Cast and my SBH

[Bearcat 74]

I have a 4 5/8" SBH that will not shoot cast bullets without leading.  I fire lapped the gun with the BTB lapping guide/compound/bullets for 100 rounds.  I drove a slug through the bore and I got .430", ok good I think?
 
My throats are .431, ok good.  I have tried .4295", .430", .431" and .432" bullets both plain base and gas checked and they all lead.  I have used Oregon Trail, Leadhead, Mount Baldy and Beartooth, 240gr - 310gr.  Bullseye, Unique, H110 and 2400. 
 
 
Today I fired 5 rounds of .431" 250gr Leadhead + 10gr Unique and in 5 rounds the first 2" of my bore leaded severely.  The only load that is not severe leading is a .430" TruShot 310gr WFNGC + 21.0grs H110, it leads but not bad.  I honestly do not want to carry a 310 @ 1250fps for a plinking load. 
 
 
Any help?  Anything I am doing wrong?

[Hit or Miss]

What do you consider "severely leaded"?  I've shot cast in all of the handguns I own and haven't seen anything that I would consider sever.  Back when I used to shoot NRA Action Pistol twice a month a gunsmith friend of mine told me, "as long as you don't get leaded in the last two inches of barrel you're good to go".  His contention was that it was where the bullet comes out of the gun that mattered.


I cleaned some pretty nice slivers of lead out of barrels and not seen any problem with accuracy.

[BigMuddy]

So many variables when leading is the problem. Just a possibility, but maybe your bullets are too hard. I know LeadHead bullets are very hard indeed.

This is taken from Glen Fryxel:

" So, for routine sixgunning applications what do we want from our cast bullet alloy? In the 800-1000 fps range we should probably keep the alloy at a BHN of 12 or below. From 1000-1400 fps, 12 to 16 is a very useful range of hardness. For velocities of 1400 to 1700 fps, this window slides up to 14 to 20. Above 1700, linotype at a BHN of 22 is an excellent choice." Glen Fryxell


 I found this to be true with a FA Mod 97 44 special. I was getting severe leading with loads at 1000 fps until I went to a softer bullet. Since your leading is in the first two inches of bore I don't think lube is the problem. I am no expert and am just guessing, giving an option.


Dan

 

[Bearcat 74]

My first 3 shots will usually go into a 1" or so group after that they start to fly all over the target.  It took me 20 minutes to clean the lead out of my barrel after today's 5 rounds using a copper brush, kroil and patches.  I could not push a dry patch down the barrel over the lead prior to brushing.

[Swampman]

I guess I'm just lucky but I've never had a gun that leaded or wouldn't shoot just about any lead bullet I put down the barrel.  Undersized bullets are usually the problem.  I wouldn't lapp a barrel under threat of death.  Are you using liquid Alox as a bullet lube?  If not I would try it.

[jhalcott]

It SOUNDS like your bullets are to hard and your lube is also. I shoot ACWW at about 12BHN that I cast myself and gas check them. I've shot this to as much as 2100 fps thru several different guns/calibers. Little if any leading results. Perhaps a boost in velocity/ pressure MAY ease the problem. Going to a higher powder charge or even a different powder could raise the pressures to where they should be. BE CARE FULL as you still want a SAFE load. In MY Ruger Super Black hawk I shoot an alloy of 10-11 BHN (WW/ pure lead)Hornady gaschecks and several weights and styles of bullets. I use a lot of Lee Liquid Alox and home made Felix lube, NOT mixed. each lube on separate slugs. Have you Checked all the cylinder throats? I've heard of some guns with uneven throats.

[Bigeasy]

Try giving the barrel a good cleaning, then slowly run a fairly tight cleaning patch slowly down the barrel.  See if it catches, which could mean a defect in the rifling the fire lapping did not remove.  Also, pay attention if it feel different as the patch enters the last inch of the barrel, as sometimes revolvers bores will be tight where the barrel screws into the frame.  If that is the case, it could be swagging your bullets down, giving a false measurement to your measured slug diameter, and causing a poor bullet fit down the rest of the barrel.  I agree with some of the above posts R/E try loading some softer lead bullets, sized to .430 / .431, lubed with a good soft lube, and loaded to about 900 fps.
 
Larry

[Mikey]

Bearcat:  I think you should run this one past Veral Smith for his take on it.  There must be something about your bullets, whether to hard or maybe the plain base is too beveled.  The .430 diameter should shoot fine as the first 3 rounds go into one inch but maybe Veral can figure out what needs fixin'....

[anachronism]

I agree with "Bigeasy". It sounds like thread choke, especially since .431 & .432 gaschecked bullets still lead. 100 lapping bullets might not be enough to clean up the throat. One other thing, my conversations with Veral indicate that he prefers one use harder lead for lapping than the soft lead Beartooth recommends. The harder alloys are a bit more aggressive in the tight areas. You could also be experiencing issues from a rough forcing cone, or might need to try a different forcing cone angle. I has a Redhawk once that looked like the forcing cone was cut with a rat-tail file. One more thing, if your SBH is stainless, you probably need to lap it more. Rugers stainless barrel steel is harder than the hinges on the gates of hell, and is very abrasion resistant.

[Swampman]

Brownell's sells a device that will recut your forcing cone I believe.

[Bearcat 74]

My SBH is a blued 4 5/8" and every time I have checked a load it has been from a squeeky clean barrel.  The .430" slug I have as driven from the muzzle through the barrel and forcing cone.  I have ran patches trying to feel for tight spots in the bore and it slides smoothly.  No rough spots that hang cloth either. 
 
The Beartooth bullets leaded from forcing cone to crown on the 1st shot
 
10.0 - 12.0grs Unqiue + 250 Lead head, 250 Mt Baldy, 240 Lazer Cast,
 
12.0grs Unqiue + 250 WFNGC Beartooth,
 
10.grs Unique + 310 WFNGC = leading
 
19.0grs 2400 + 250 Lead head, 250 Mt Baldy, 240 Lazer Cast = leading
 
21.0grs H110 + 310 WFNGC = light leading - 2" group at 25yds repeatedly - kicks like a mule
 
 
The gun shoots really good.  240 XTPs, 300gr Sierra, and 240gr Nosler SP's all will go around 2" at 25yds which is about as good as I can do.
 
 
I will try lapping with the Leadheads if you think that may help? 
 
 
I almost swabbed the bore with lapping compound and and fired a cylinder full.

[myronman3]

have you tried a different powder?   is your bullet gas checked?

[leadman]

It is possible you are swaging down your bullets if you are applying a heavy taper crimp. If you have a kinetic bullet puller remove a bullet and measure it. Sometimes even a too heavy roll crimp will do this.
 
 

[Bearcat 74]

Update time guys.
 
 
I bought the Brownells forcing cone cutter for an 11 degree cone.  It came out looking good but I still had mucho leado.
 
 
While pondering in my work shop I realized I was making basically no progress and decided to take a new approach to lapping.
 
 
I had a constriction under the frame, nothing new there.  After 100 lapping round not a whole lot had changed.  I got some coarser compound, broke a q-tip and applied the compound to the forcing cone/barrel under the frame area. 
 
I loaded a harder bullet, 22 hardness, over 3 grs Bullseye and fired 12 rounds while applying the compound after every shot. 
 
Results, HUGE improvement, huge.  Leading is basically at zero, one small tiny spot but not enough to worry about.  I fired a load that I know is accurate, 240XTP+19grs 2400, at 25yds rested off my knees and got a 1.98" 5 shot group.  I claned everything down and I have fired 15 rounds of lead and I have basically zero leading where before I was leaded up after 1-5 rounds.
 
 
Thanks

[Lloyd Smale]

Glad you got it straightened out. Ive lapped many guns and have yet to see it hurt a thing and in most cases accuracy improved and it took care of leading in a few guns. Ive yet in all my days seen where a bullet that was to hard caused leading in a gun with proper dimentions. I cringe when i hear so called experts recomend soft bullets to bump up in a bore. It might be a bandaid for a gun that has to tight of throats but its usually an easy fix to open up the chambers to proper dimentions. To small of a bullet can cause leading. As can some powder/bullet combos and ive even seen where a different primer eased leading some. Commercial bullets can be the problem but not becaue there to hard. Mostly because they use hard comercial lubes that are not much better then using no lube at all. Im also not a fan of tumble lube. Its messy, it attracts dirt and it doesnt lube near as well as a good soft lube in the groves. Ill sometimes use it in something like 38 specials when im lazy and dont want to bother sizing them but ive had enough problems with misfires and squibs using it because the lube on the bases gets soft in hot weather and migrates into the powder that i rarely bother with it anymore. One thing its good for though is testing when you have leading. If you suspect that the hard comercial lube is the problem and your shooting low velocity loads tumble lube those allready lubed comercial bullets and try them like that. If leading decreases you at least know that its a lube problem. Most lube problems will show themselves with leading toward the end of your barrel though, not at the first part. Most leading in the first few inches of your barrel is caused by constrictions, poor forcing cones and alignment between the cylinder and barrel. A pourly fit (to small) bullet will usually cause leading the entire lenght of your barrel and in some cases so can a barrel constriction. The soft bullet advice though is a pet peave of mine. In all my years of shooting handguns ive yet to see a GOOD gun that didnt shoot hard bullets better then soft and my buddy and I have done some pretty extensive testing to prove it. Ive also NEVER seen a soft bullet cure leading. In a missmatched gun it will sometimes reduce it a bit as long as your backing off your loads too but if your gun leads and your trying to still shoot full power loads your wasting your time trying softer alloys. Your best bet is to do just what your doing. First try to fix the problem with the gun.

[Fire Fox]

When I shot Competition with swaged soft lead bullets I had the same problem and found two causes for me I ordered the re throating tool from brownell to change the throating on my barrel. It is easy to use just be careful not to do too much. The other thing is that many people think that a jacketed bullet will clean the lead out of the barrel. This is false be sure that you have cleaned all of the Gliding metal out of your barres before you shoot lead Gliding metal deposits in the forcing cone and barrel will cause leading. Another thing to think about is that equal charges of powder in jacketed bullets are slower that the same charges in cast. In my 44 mag revolvers 22 gr of H2400 gives 1400 fps in 240 gr jacketed but the same charge in the Keith 250 gives 1550 for me and leads but reducing to 20 stopped it and gave about 1450 fps. In my experience most of the time a good lapping compound from Veral Smith, the brownell tool and making sure no gliding metal in the barrel does the job. Hope this helps.


PS be sure to use the correct degree angel for cast bullets when using the brownell tool.