How far out of round is accptable?

[Gremlin460]

Hi guys, just asking the question of all the casters , how far out of round do you feel is acceptable? before resizing is done.

Fresh and new to casting (less than 3 weeks), I have been happily casting away for a few days. I now have approx. 4000 boolits cast from a Lee 124g 6cav mold.

I have weighed a crossection and found they tip the digital scale at 132.8gn +/- .3.
Then I found my non-metric micrometer and went through a few samples.
Measured across the mold joins they measure 356.2 and across the face of the mold halfs they measure 358-359 depending on how tight I was holding the handles.

I will be slugging my bore this weekend to find out what my exact bore size is, but for this example , lets say it slugs at 356.

Are these boolits going to size down to that or am I going to have to work on the mold?
To drop the wide measurement down, I will need to shave both faces of the mold, and this means I will have to re-cut the vent lines.

So, before setting this up in a mill to take .005 off each face, I thought I would ask the question, how far out of round is acceptable, and what has been you experiances in this area..

Mike-AU

[Larry Gibson]

What alloy are you using?

Bottom pour, ladle or dipper?

Casting temp?

Larry Gibson

[725]

Try and shoot a couple before you go to all that work? Any thought to just lapping the mold?

[blackbike]

Sounds like some thing is holding the two halfs apart.
Check alinement pins, dings, lead deposit,. ect.
I would not jump up and do some thing I couldn`t undo without a close look.
bb

[btroj]

Shoot some, they may work just fine as is.
What gun? If for a 9mm that is to be shot at ranges under 50 yards I doubt it will make any real difference.

[Gremlin460]

Sorry, did not think to include all the additional details.
I started with 660lb of WW, these I cast into 220 Clipon 1lb muffins and 118 stick on muffins, I did keep them seperate, the muffins are letter punched C-clip-on S-Stick-on and X-soft lead pipe and wierd stuff. Some of them in this pic:-

http://s881.photobucket.com/user/Gremlin460/media/IMAG0206_zpsbc41d2ff.jpg.html?sort=3&o=16#/user/Gremlin460/media/IMAG0206_zpsbc41d2ff.jpg.html?sort=3&o=16&_suid=137968162712703345615032481041

I use a cast pot and ladle to pour and find it brilliant, fast clean and very easy, so much so I will never bother with a bottom pour. Moving on... all the casting have nice fillouts and very good bases. They drop fairly easy from the mold without much provoking, here are some I did 2 days ago...

http://s881.photobucket.com/user/Gremlin460/media/IMAG0214_zps75ac0935.jpg.html?sort=3&o=8#/user/Gremlin460/media/IMAG0214_zps75ac0935.jpg.html?sort=3&o=8&_suid=1379681889942018123793465619364

The temp, is just over melting point and I keep a good layer of charchol on the surface of the melt, I find it childishly simple to sweep and fill ladle with lead, and let the sawdust cover close back over the melt.

Once I had lead specks on the face of the mold, but it threw boolits that were obviously incorrect and they were returned to the pot.
I have tested many from all the batches I made, and the size in my first post hardly ever varies, all my castings are Water quenched, and I stick to a rigid regiem of 3 clipon muffins to 1 stickon muffin when topping up the pot.

They may well shoot as is, but i am the kind of old guy that likes to get it right. I have as yet not bought a sizing die, obviously as I havent slugged the bore. I was just wondering if sizing assists a boolit in becoming circular from this .002 oval I currently cast.

Mike.

[Browningshooter]

In answer to your last question, yes sizing the slug will bring it into round as long as you are sizing smaller than your skinniest measurement. If you find your boolits are undersized after you have learned your groove dia. You can look up "beagling a mold" on this fine forum and get it to drop a touch larger. Also adding tin, casting hotter fan give you a little more size sometimes.
- Will

P.s. I would shoot them first as suggested by others and also agree that at short pistol ranges a little out of round don't matter....


Also, your ladle technique can also cause issue due to the lead heating one side of the mold halfs more than the other resulting in better fillout on the bands where the hottest lead hits repeatedly. Do you "pressure pour" with your dipper? I.e place the nozzle on the sprue and turn the mold upright while the dipper stays in contact with the sprue?

[Browningshooter]

I just noticed Larry Gibson has seen this thread. I would certainly follow any advice he has for you and hope he will correct me if I have steered you wrong in the above post...
- Will

[williamwaco]

You are very likely causing the problem by the way you are holding that Lee 6 cavity mold.

When casting with any Lee 6 cavity mold:

DO NOT allow any part of your hand to touch even lightly, the sprue lever until the mold is filled and you are ready to cut the sprue.

See

http://reloadingtips.com/pages/missing_tumble_lube_grooves.htm

Scroll down the page to look at the pictures of the mold and the gap caused by even very light pressure on the sprue handle

That is normal diameter for that bullet with that mold.

Yes, you do need to size them. You will find that many of them will not chamber if you don't

Yes, as stated above, Listen closely to whatever Larry Gibson says.

[Larry Gibson]

Couldn't open photobucket for whatever reason......

Make sure the 6 cavity mould is held as mentioned and make sure the block are closed to begin with. do not, as mentioned apply and pressure/hold on the sprue handle.

Lots of COWWs with additional lead added (SOWWs). Your alloy is obviously very poor in tin (not all COWW batches are created equally).....some batches work well, especially older COWWs, w/o adding tin but most don't these days. I suggest you try adding 1 - 2% tin to some of the COWWs and then add your SOWWs. That will dramatically improve the alloy and also give much better and more uniform fill out.

Also suggest you up the temp a bit to 720 - 730 degrees for casting. Your alloy cools a lot between the scoop and the fill.....hard to believe but it really does. If you are at just liquidity in the pot it is too cool going into the cavity.

What "ladle" are you using? Are you filling each cavity individually? Are you leaving a good sprue? Those questions might have been answered in the pictures???

Larry Gibson

[Gremlin460]

I brought the barrel home from the range today and slugged the first 1" or so, both times it came out at 3562. I the went back to the boxes of boolits. tested the micrometer and made sure it was zeroed correctly and after many many boolits , have a result of 3573 to 3582 across a large selection.
I shall purchase a 357 sizing die, that should give me .001 crush from the boolit to the bore fit.

The ladle I am using is a mid size soup ladle, that I have formed to provide a spout, I typically fill it with enough to do 4-5 molds fill. The larger volume keeping the heat better. I pour the mold on the lip of the casting pot from a height of around half and in and get nice 3/4" wide sprues forming in a dead straight line.
It is a fast pour, I do not trickle feed the lead. boolit fillout has always been good.
When I say a cool pot I mean I avoid heating to a golden sheen appears on the top of the lead.
I pace my pouring speed to just below frosting of the boolits, which I have done, and the mold seems to behave well at that cycle rate. approximately 3 casts per minute from pour to pour. If I set up to 4 pours a min, after a few pours I start getting frosting again due to the mold temp.
I am very happy with the dropped results, I was just concerned buy the amount that the projectiles are .001 out of round.

After each pouring session the mold, when cold is stripped serviced/cleaned/lubricated and wrapped up and put away ready for the next time.

Looking at the slug results, I see well defines riffling and the single lube grove is still present even in the riffling, each riffling grove has the same amount of lube grove showing, telling me the slug rounded well after being driven into the bore.
I believe those that say these would work "as is" without resizing, but I will size just to be sure.

Mike.

[John Boy]

how far out of round do you feel is acceptable?
The rule of thumb for mold makers is if the cutter is within 0.002 the mold is acceptable and if the bullet bases are the same variance they are acceptable


The temp, is just over melting point and I keep a good layer of charchol on the surface of the melt


When I say a cool pot I mean I avoid heating to a golden sheen appears on the top of the lead.
Obviously, you are casting without a thermometer and have no idea what the melt temperature is. That's your 1st problem and it has nothing to do with the mold

Cast bullets will be in the 0.002 base diameter tolerance IF:
* You hold the mold up to the light and there is no light visible between the 2 mold halves
* (a) USING A THERMOMETER - (b) heat the pot melt to a temperature so than when you pour FOR 5 SECONDS ... ( c) the sprue puddle FROSTS BETWEEN 5 - 8 SECONDS.

Follow this 3 simple steps and your bullets will fill out to the diameter tolerance of the mold

[Gremlin460]

Thank you John, no I do not have a thermometer, I do however check the mold for correct closure each time. I again reitterate I have no problems pouring, I have no problems with the melt. All I asked in the beginning was how much out of round is acceptable.

I have thousands, of boolits, I have obviously not measured thm all but around 60-70, they all show exactly the same variance. 3572x3583, so the casting is very consistant.
The sprue cools in your stated time frame, 5-8 seconds, after cutting the sprue I check bases for wipes or poor fillouts and round bases. I have very sharp edged base and am very happy with the molds performance.
What my concern was, would the oval projectile size satisfactorliy . After talking to several members in the chat on this site. It seems my fears were unfounded. the .0011 run out will be corrected easily with a 357 sizing die.

The oval result i am getting is so constant, I cannot imagine it is pour temp related, even without a thermometer I doubt I could get 8-9 pots on different days to the exact same temprature using a propane stove.
My mold is definaely out of true by .0011. However you have all managed to quench my fears that this variance is beyond recovery. That is what i needed to know.
I had visions of having to lap and polish the mold to try and reduce the difference in mesurements.
Some of you long term casters would have seen what I had, and known it was withing acceptable tollerances, being a 3 week old caster I was not sure, so I asked.
If I turned a shaft up on my lathe and it had this kind of deviance I would deem it to be scrap and make a new one. I guess boolits are a little more tolerant yes.

[Larry Gibson]

I again reitterate I have no problems pouring, I have no problems with the melt.

Could be the mould and your bullets may shoot just fine for you. However, you may not have "problems" with pouring and the melt but those no "problems" may vary well be the reason for the "how much out of round is acceptable" question as your bullets show more out of round than you think they should and they do.

A change in what your using and how you do it may easily solve the problem.

Larry Gibson

[Mk42gunner]

...To drop the wide measurement down, I will need to shave both faces of the mold, and this means I will have to re-cut the vent lines.

So, before setting this up in a mill to take .005 off each face, I thought I would ask the question, how far out of round is acceptable, and what has been you experiances in this area..

Mike-AU

Mike,

Before you try to mill the faces of your mold, check very carefully around the alignment pins. I have one six cavity Lee that evidently wasn't supported properly when the pins were pressed in. An area about ½" in diameter was standing proud of the surface and caused me fits finding what was wrong.

My boolit measurement was a bit more extreme, .312x .322 on some casts, round .312 on others.

It was a group buy that I waited too long to cast with so I wasn't about to send it back to Lee.

The rest of the advice you have been given sounds right to me.

Nice city you have there, I lost a set of keys in the middle of the Brisbane river while we were getting underway in Jan 1988.

Robert

[Gremlin460]

just ran the inside mics around this Lee mold, it is definitely 3572x3584 inside dia.. but I can live with that.

Next time I go fishing in the river ill look for your keys Rob, but I wouldn't hold out for success!, besides after the years of floods, they probably out to sea by now..