Out of round bullets

[mattd]

Got a group buy alum mold that should be casting 318 but i'm having a hard time getting round bullets. Getting 316-320 on a single bullet, and the diff is at the seam. Spent hours at it now and I've tried everything I can think of and am out of ideas.


50/50 alloy w 1-2% tin added. Upped the tin to ~3% while troubleshooting. Running my Lee 20lbs pot thru about all the temp settings. Tried pouring by force feeding direct from spout, with a half inch drop below the spout, an inch, 2+ inch drop and in between.


First tried lubing the pins w 2 stroke. Also tried carnuba red bullet lube, but most efforts have been with the 2 stroke.

The blocks don't have any light coming thru. Cleaned the faces with soap, water and a nylon brush and examined for any remaining specs. No luck. Cleaned w brush and kroil and let soak over nite then brush and kroil again. Re examined, no luck. Wiped the faces w cotton cloth while at casting temp. Carefully scraped the steel alignment pins w an exacto to clean them and they got the same kroil brush treatment.

After 400+ casts i do have 21 keepers that are 3175-3185. Not sure what was diff for those. They were just random in the middle of the others.

Any ideas? Would really like to make this one work.

[texassako]

Can you see light between the blocks when it is shut? If I have an out of round issue and the blocks are closing all the way, it means something is up with the mold itself. No amount of casting technique is going to fix a mold with out of round cavities. Is the bullet wider or skinnier at the seam?

[mattd]

No light.

I can't measure the seam like that. It's like one mold half is shifted toward me, and the other away. The two halves aren't flush with each other to create a measurable seam. the blocks halves aren't lining up.

[bangerjim]

Group buy????? From who????????? The maker should stand behind it and either fix it or send you a new one.

Contact whoever you bought it from.

banger

[mattd]

I'm certain he would stand behind it. But if its something I can fix then it might save some time,

[waksupi]

Check your handles. Is there enough pivot clearance? I have had to shave down some on the inside outer ends to let the molds close correctly.

[Springfield]

If the mould halves are shifted side to side, and the pins are all the way out and the mold is tight with no play, then it was mis-cut. No way to allow for that except to size smaller the the smallest dimension. Doesn't mean the bullet won't fly straight, though.

[mattd]

I could size and be fine, but figured the nose would still be cock eyed and be out of balance.

[Larry Gibson]

If it is a Lee 6 cavity mould do not hold onto the sprue plate handle when casting. I will pivot the blocks apart. If another make make sure when the sprue plate is closed it does not misalign the blocks.

Since you get such a wide variation of sizes with some at what they are supposed to be it means the something is wrong with the alloy or you are doing something wrong. Need to find out which. Suggest you change out the alloy with one of COWWs + 2% tin and cast at 725 degrees. If those cast out within tolerance then we know it is the alloy. If not then we need to find out if you are still doing something wrong or if it is the mould itself(?).

Larry Gibson

[montana_charlie]

Take the mould out of the handles.
Wire the blocks closed with copper wire snugged quite firmly.
Pre-heat the mould and pour a bullet with good, hot, alloy.
After it is all cooled down, remove the bullet and see if it's halves line up.

If they don't, return the mould to the maker.

CM

[bangerjim]

Like I said...........contact the supplier!!!!! It's a new product, it is defective, he should stand behind it. If not, let us know who it is....so we can avoid him in the future!!!!!!

Don't waste your time fixing something that SHOULD BE/IS covered by the mold maker.

bangerjim

[mattd]

Since you get such a wide variation of sizes

i don't really have a wide variation. I have hundreds that measure 316 on one Side of the seam and 321 on the other. And then 21 that are round.

Don't have a thermometer, but started with fresh COWW and add 2%+ tin, then set my Lee pot on 3, which is lower then I normally cast at, and went up in half increments, giving the alloy at least 20 minutes to heat up each time.

Also tried it with out the handles, and casting in my hand. That's HOT!

Same result. Guess I'll see about sending it back and entertain myself with the 21 round ones in the meantime.

[Old Caster]

i don't really have a wide variation. I have hundreds that measure 316 on one Side of the seam and 321 on the other. And then 21 that are round.

Don't have a thermometer, but started with fresh COWW and add 2%+ tin, then set my Lee pot on 3, which is lower then I normally cast at, and went up in half increments, giving the alloy at least 20 minutes to heat up each time.

Also tried it with out the handles, and casting in my hand. That's HOT!

Same result. Guess I'll see about sending it back and entertain myself with the 21 round ones in the meantime.

Since you sometimes get bullets that are correct, I would guess that your mold is not consistently closing the same. The most likely thing to cause this is the alignment pins are not sticking out far enough so there is play. When the mold is cool, can you take your hands and twist on it while the sides are closed and move them. If yes, close the mold and tap the alignment pins farther into the block until they stop from seating on the other half. Don't be rough when doing this because you could move them too far.

[Safeshot]

If you have a bullet sizing die, you might want to run some of them through the die lube them, load them and fire them. They might shoot better than expected. The Boolet will be reformed by the bullet lead in the chamber/bore and by the rifling. It will be "different" when it comes out of the muzzle. It MIGHT shoot well enough to be useful. While you are doing this with the (off set - out of round) bullets you have already cast, send the mold back for repair or replacement. You will then have experience that may be useful later.