offset round ball mould

[RichG]

anyone ever have a mold where the two halves don't line up? I have an old lyman .526 mold and the halves are mis-aligned by .003.
Any Idea on fixes?
Has anyone compared how a ball that's out of round will shoot compared to one that's round?

[Sharpsman]

And out of round round ball will shoot out of round!

[Daryl]

I had a DC mould, with one cavity casting .400" X .400". The other cast .394" x .400". The oblong ball, which would likely shoot similarly to one with offset 1/2s, more than doubled group sizes at 50yards.  I've posted that picture here a number of times.

The .400's X .400's shot about a 1/2", 5 shot group at 50yards, rest.  An offhand group same balls went about 1 1/2".

The oblong ball shot a 2 1/2" group off the bags and pretty close to 4" or maybe 5" offhand.

This shows quite emphatically, that if the load does not group off the bags, it will shoot even more poorly offhand.

[RichG]

Daryl-
that's good to know. if I can't figure out how to fix the mold I'll have to replace it.

[Hungry Horse]

I Can’t give you advice on fixing a mold if you don’t tell us what type, and or brand, it is. Sometimes handle not intended to fit certain mold can be screwed on and will create such a problem. Aluminum molds wear with age, and can become misaligned. Old fashioned bag molds are notorious for this problem.

 Hungry Horse

[Daryl]

All of those, Hungry Horse noted, along with if RCBS, Ohaus, or Lyman,Saeco, the locator pins may need adjustment in protrusion length.

With use and banging the blocks together, they get shoved more deeply into the blocks themselves.  If not protruding enough, only the rounded,

smaller diameter of the end engages making the blocks loose fitting, causing alignment problems.

[RichG]

lyman single cavity small block and I'm using small lyman handles.

noticed halves would move when held together. After looking at pins I saw a burr on one . Knocked the pin out, de-burred and reassembled. Tapped pins with a punch until halves no longer moved and cast some balls. Still not aligned.

The mould doesn't look abused or even used much.

How would I get the pins to move the two halves together?

[Marcruger]

Considering the cost of your gun, the cost of lead, and the cost in time molding bullets and at the range......well, I'd buy a new mold. 

[Maineshops]

They just make out of round holes😋

[Scota4570]

I'd remove the alignment pins.  Make sure the holes are true.  Make sure the pins are good.  Reassemble, see.  Failing that you may be able to reverse the pins, to the other block.  IF there were some wear on the holes that would start you over with new holes for the pins to go in. 

Was it always messed up?  Try long extended pins and see.  That would tell. 

Plan B...  Get a Lee mold.  : )

[P.W.Berkuta]

anyone ever have a mold where the two halves don't line up? I have an old lyman .526 mold and the halves are mis-aligned by .003.
Any Idea on fixes?
Has anyone compared how a ball that's out of round will shoot compared to one that's round?

YES - if you don't like the mis-alignment buy a new mold. You are wasting your time and energy on trying to fix a bad mold. Not that I'm a fan of Lee molds I would buy one if I did not want to spend the money on a Lyman cast iron mold. Call Lyman and see if they can help you with your mold?

[Daryl]

Calling them is one solution, just to see what they say.

[RichG]

It's an older mould, I believe I got it of Ebay. Lyman no longer lists a .526. I think I'll try switching pins. If that doesn't work, new mould.

[smylee grouch]

Last spring I had a .605 mold that was off by about 3 or 4 thousands, out of round, but it was too small any way so as I waited for a .610 I did some testing. I cast up a bunch of the 605s and then indexed the mold cavity with a center punch(small dimple) just below the sprue. Then cast up a bunch of them and the indexed (put the dimple facing me as I loaded) balls shot groups about 30-40% smaller. The groups were not as good as I wanted so I ended up using the .610 balls and they shot real good.

[Daryl]

Off centre is a bit different than oblong. I've fixed a couple bullet moulds that cast oblong bullets. The cavities lined up, but one side seemed not cut deeply enough.  A thin shim or two of tin foil on one side, held to the block with red- high temp silicone 'fixed' the 'bullet' moulds. Misaligned blocks is a different problem.