Troublesome Mould

Ben

Ben

Moderator
Staff member
I bought a single cav. Lyman 358477.
From the " get go " , it was a troublesome mould.
The mould was out of round. ( I fixed that by spinning bullets with fine Clover's abrasive compound until I was closer to round )

The mould didn't want to cast a bullet with a base that was filled out.
I cleaned the mould about 1/2 dozen times, that didn't help a single thing.
So, ........I took a fine cut Swiss flat file and layed it on the edges of the top edge of the block at about 10 degrees and removed a bit of metal.
PRESTO ! ! Perfect bases on every pour.

Then I noticed that the sprue hole had burrs in it.
The sprue wanted to stick ( I just hate that ! ! )
Nothing to do but to re-cut the sprue hole.

eD7tURy.jpg


All is well now.
A bit of work, but none the less, a fine casting mould.

Ben

0VvZgKd.jpg


Now I'm getting good base fill out with no whiskers.
( Please be very careful with this technique, you don't want to remove
too much metal. Keep the file on a very low angle. Stop after you've removed a VERY SMALL amount of metal and cast with the mold to see if bullet base fill out has improved )

HIul4aL.jpg


The photo below makes it look like I've removed a lot of metal.
Not so ! The file is held on a very low angle. When the blocks are closed, the fine crack at the tops of the mold halves when the mould blocks are closed probably isn't as big as a vent line. However, it makes a tremendous difference in the way the mould cast. THAT AIR HAS GOT TO GO SOMEWHERE.
WjhFn87.jpg


The end result is a fine casting mould.
Notice that you don't see " whiskers " on the bases of the bullets.

The air is venting well, but the file work has not been overdone.

yCXK1DF.jpg
 
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Ben

Ben

Moderator
Staff member
Cherokee,

Yes, it is a great bullet design.

I guess old Elmer would be proud of some
of us that still brag on , cast, and shoot his designs.

Would have been nice if this one was a multi-cavity mould, but..........at least I'm assured of consistency ( bullet to bullet ) since these are coming out of a single cav. mould. They drop from the mould at .3595 "

These size out well in my .3575 " lube / sizer die.
I've used this one die to lube and size cast bullets for many 38/ 357 revolvers with excellent results during the past 50 years.

I have about 250 of these cast, sized, and lubed now.
I have about 7 different 38/357 revolvers to try them in,
along with a pair of 38/357 Mag. rifles.

Ben
 
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Cherokee

Cherokee

Medina, Ohio
I've got a 4 cavity I bought a long time ago. Sent many of them down range thru my SA & DA revolvers. Have fun !
 
358156 hp

358156 hp

At large, whereabouts unknown.
The 358477 isn't quite a Keith design. Lyman basically knocked off Cramers #26 and added a heavier base band. The #26 which was a knock off of the H&G #51, which was a collaboration between Wayne Hensley, and Keiths arch-enemy Phil Sharpe. I guess it could sort of be a Keith design because ol' Phil cut, pasted, and tweaked the 358429 to develop "his" design.

Those were crazy days. Everybody copied everybody. We don't do that today:rolleyes:
 
Brad

Brad

Benevolent Overlord and site owner
Staff member
If you did would it be less than Ideal?

Ben, I have many moulds that needed that same fix. I have one that gave over 50% rejects for rounded bases until I filed that bevel.
 
smokeywolf

smokeywolf

Well-Known Member
Never had to doctor or massage a IDEAL mould.

Good example: an IDEAL 429421 sitting here by the computer. Double cav., no vent lines, makes great bullets.
 
Ben

Ben

Moderator
Staff member
Brad said:
Ben, I have many moulds that needed that same fix. I have one that gave over 50% rejects for rounded bases until I filed that bevel.
Click to expand...

Like we all know,..... that air has to go somewhere.
Give it an escape route and you are good to go.

Ben
 
smokeywolf

smokeywolf

Well-Known Member
Always surprises me when I run into someone who doesn't have a basic grasp of physics and fluid & thermo dynamics. When I was a kid, we learned these very basic principles in jr. high science class. Seems like classes in social/ethnic/cultural diversity have "displaced" much of the sciences.

Not only does the air that the lead is displacing need to escape, the instant the lead begins entering the cavity it causes a sudden and dramatic increase in air temperature resulting a rapid expansion of the air. Insufficient avenue(s) for escape of that expanding air puts puts yet greater pressure against the rising surface of the lead.

Forgive me if I'm "teaching my granny to suck eggs".
 
Cherokee

Cherokee

Medina, Ohio
Some of us did not understand "a basic grasp of physics and fluid & thermo dynamics" very well at the time but have learned the practical side over the years.
 
Ben

Ben

Moderator
Staff member
The school of hard knocks can offer a VERY good education in that arena.
 
9

9.3X62AL

Guest
My few Ideal moulds haven't needed this sort of mod, but several more recent Lymans surely have--as have a few RCBS blocks. Accurate, NOE, and Mtn Molds run like water down a drainpipe after 3-4 heat cycles without exception. I believe my days of new Lyman or RCBS moulds have come to an end. With the semi-custom toolmakers doing such good work for such reasonable pricing, it is silly to throw good money after a tool costing close to the same amount that you will have to finish building.

Just thought of something......HORRORS--I have 4 new moulds on hand now that have not yet been cast with at all. This includes a 4-banger NOE in #358477. It actually got below 100* for the past couple days, so I see a window of opportunity for some tool time near-term!
 
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