forcing cone leading

[turmech]

I shot my first bullets I cast yesterday. I shot 12 shots and disassembled the gun to inspect for leading. The gun was remarkably clean. I did find some leading on the forcing cone. The leading was on the bottom (say positioned from 7:00 to 5:00). Not much and it was easy to remove (1 pass with brush and solvent). I was initially pleased with this minimal leading but have since had some concerns as this leading I believe effected the point of impact after shot 5.

Shot 1-5 had the point of impact 2.5” low and 2” left but with good grouping (in fact better than my jacketed loads). Shots 6-12 had the point of impact near perfect with good grouping as well. I do Know that fouling shots are mostly considered necessary but with this limited information I would suspect this to change in point of impact to continue as it is shot.

This was my set up: Lyman 429421 mold. Not sized came out of mold at .430 and seemed perfect for the cylinder throat (I have not purchased a sizing Kit as of yet). WW allow + 1.5% tin water dropped. Boolits aged about a week before shot. Pan lubed wit TAC #1. 19.5 g Allaint 2400 with a heavy roll crimp and standard LP primers. OCL 1.68. Target shot at 25 yards whit a Blackhawk hunter 44 mag with clean barrel at the start outside temp 40.

Anyone have any suggestions as to what changes to make which may stop the leading?

[Reload3006]

with the gun clean take a q-tip (cotton swab) and wipe around the cones (revolver i assume) to see if there is a burr. The most common cause of leading in the forcing cone. If that is the case Brownells and Midway sells a kit to lap polish the cone will help you immensely. If that doesn't solve it increase the size of your boolits to match the forcing cone.

[462]

Don't know of what you refer to as a "sizing kit", but all you need are soft lead slugs, to push through the cylinder throats. Measure with a micrometer. If you don't have any stick-on wheel weights to make your own slugs, barrel-type lead fishing sinkers of the appropriate size work. I size .001" more than the largest cylinder throat.

You may want to consider having the forcing cone cut to 11-degrees, rather than the factory five. Doing so helped my Blackhawk.

I don't own a .44 Magnum, but with the .357 Magnum, my experience has been that boolits cast of an alloy softer than straight wheel weights (2:1 wheel weights:lead and 50//50) and air-cooled rather than water-quenched, perform much better.

[turmech]

By sizing kit I am referring to either Lyman lubsizer with a .430 die or a .430 lee kit for the bullets. I did not purchase a sizer as the mold produced bullets that seemed perfect for the cylinder throat with out sizing.

I have not slugged the barrel as without opening the cylinder throats the throat size would determine the final sized bullets that would go into the barrel. I was using bullets sized for the throats. I figured if I had leading in the barrel I would look into slugging the barrel (barrel constriction).

[Reload3006]

a person that I totally respect who never steered me wrong asked why I sized my boolits because I had 6 sizing dies on my revolver. as long as your cylinder throats are polished and burr free. the forcing cone is polished and burr free. you have good lube on your boolits and they are big enough to seal the throat. you should have very minimal leading. You may try different velocities and hardness of lead alloy.

I Lube Size because it for me is the easiest way to lube my boolits not because I necessarily want size. It does help to make them more uniform.

The only time i have leading in my Smith 29 is when I use pure lead (swaged boolits) and use magnum velocities and it leads on the forcing cone just as you described. If I use harder alloy it does not lead. So you may want to try and see if your load is causing you some problems.

[turmech]

Do you have a procedure you use to on your throats and forcing cone to polish them? I was considering firelapping for just such a reason.

[runfiverun]

it takes a few shots to get lube worked down the bbl.
i have counted on my rifles and it generally takes from 7 to 11 to get a lube or carbon star to appear at the muzzle.
i'd go back to the range and see if your cleaned bbl repeats what it done before.
then i would shoot some more and see how things shaped up before i started looking at changing things.
what you see from 12 shots is nothing..

[Reload3006]

http://www.brownells.com/.aspx/pid=2...uct/BRASS-LAPS
http://www.brownells.com/.aspx/pid=6...FLEX-HONE-reg-
My suggestion is use the finest lapping compound you can get no need to be in a big hurry.

[geargnasher]

Ruger forcing cones are sometimes rougher than a cob and need a little polishing to keep them from raking lead off the boolit.

Gear

[fredj338]

Pin gage the cyl throats. Ruger sometimes gets tem on the small size. This always causes leading in the bbl forcing cone. Opening the cyl throats to a uiniform groove dia will help a lot. It did on my 45colt RBH. My 44mag RBHB has 0.4305" cyl throats.

[ColColt]

Ruger forcing cones are sometimes rougher than a cob and need a little polishing to keep them from raking lead off the boolit.

Gear

Rough indeed. Would the brass lap in the Brownell link help a somewhat rough FC that leads on one side? How does it work? What I mean is what do you attach it to?

[stubshaft]

It doesn't matter one bit how polished the cylinder mouths are if they are smaller than the bore.

[geargnasher]

Stubshaft, you are correct, but I was talking about the forcing cone in the barrel, not the cylinder throats (or forcing cones, I guess those are technically forcing cones, too).

ColColt, it will sure help. The place the OP was talking about the leading occuring makes me think he has a timing and endshake issue tool.

Gear

[runfiverun]

i wouldn't think it was timing unless the gun was still very tight but unaligned.
but that usually shows up on the side of the forcing cone.
that boolit should pull the cylinder and throat in alignment it were just loose.
and leading should then be spitting or showing up on the face of the cylinder.
the leading is on the bottom of the throat so either the nose or the front driving band is making first contact there.
i'm guessing it's just a tight spot or roughness there.

[stubshaft]

I understand Gear but was referring to the fact that Turmech hasn't even slugged the barrel yet.

[44man]

Yes Ruger forcing cones can look like they were cut with a pickaxe. The laps are brass that you coat with a fine abrasive and turn in the cone. You need the rod and bushings that go in the bore.
Next is the semi wad cutters little shoulder that gets wiped off at the cone if all is not perfect. The nose does not steer the boolit into the cone.
In 56 years I never found a reason for the shoulder!

[turmech]

First let me start by saying I am a novice to casting bullets and shooting cast bullets. I also am not against slugging the barrel, but I can’t see how information gathered by slugging the barrel would help with the leading of the bottom of the forcing cone. The whole forcing cone yes, as a barrel restriction or grove diameter problem I would think would cause that.

My logic as to not slugging the barrel is I am not planning on opening the cylinder throats to be able to shot cast bullets. So If my throats (.430) are too small for grove diameter I would just continue to shoot jacketed or sell/trade the gun. I figured the bullet/gun would let me know if I had enough restriction by downsizing the bullet and gas cutting with the typical lead placement.

This gun is nearly new. The cylinder is tight. The cylinder face is lead free and has a acceptable gap to the forcing cone (.0045). I am planning to shoot some more of the same load and some loaded a 19 g of 2400 to see what happens.

As stated new to cast bullets my reasoning may be wrong. Thanks for all the help so far.
Any one think out of round bullet as I did not size the bullet?

[Reload3006]

I dont think its out of round bullets. and I do agree that fit is king but even fit isn't the cure all end all. you may need a harder lead boolit or a lighter load instead of using 2400 trying for a magnum load try unique and a milder load. Try a gas check. sooner or later you will find that sweet recipe of alloy boolit and load to make your revolver happy. But if your forcing cone or throat is rough its going to lead no matter what you do but that is easily fixed with out altering your gun. Just shining it up. really. Gunsmiths do this all the time. They take OK work from the factory and do some precise finishing and make a good gun better.

[turmech]

I may try unique if 2400 still leads in further test as I already have some on hand. I will probably try to polish the forcing cone first before switching powders. I am young and dumb and only find full house loads interesting.

[Reload3006]

I used to be that way too. but have never had a deer complain about being killed by a boolit going a couple hundred feet slower he was just as dead ... Best of luck to ya.