Acceptable Out-of-Round

[hammer58]

I am still learning about casting and am sure you guys can give me some advise. I just cast a couple of hundred boolits for my 1911 in .45 cal. I am using the Lee TL452-230-2R mold and an old small Lyman (I think) pot. It has no temperature control and is a ladle pour pot.

I know I should have checked sooner, but after casting them, I decided to make sure they were pouring to the proper size. That's when i found that they are measuring anywhere from .448" to .456" and most of them are out of round anywhere from .001 to .004.

I have already fired about 400 of these lubed with LLA and have seen only a small amount of leading.

What is an acceptable out of round for these boolits? Should I get a .454 mold and size them down to .452 to make sure they are the right size?

[Outpost75]

For practical purposes 0.05% of bullet diameter...

[Bzcraig]

Generally speaking once you size your boolits they come back to round or certainly within allowable limits.

[hammer58]

It was my understanding that the Lee TL boolits are designed to shoot without sizing. I guess I should invest in a .452 sizer? But if some of the boolits are measuring smaller on one side than .452 would I be better off getting a .454 mold then size to .452?

[happy7]

Keep in mind that out of round is not that bad. Out of balance is. Usually if a bullet is out of round, it is across the part line. If you think about it, it is still balanced. Sizing a bullet doesn't really change that much in terms of out of round because often it just fills in lube groves. But sizing does not necessarily change the balance. Molds that have been lapped can be out of round and no amount of sizing will bring them in balance. A bullet will also be sized by the barrel as it travels down it. So my take on it is that it is not that big a deal, especially if it is across the part line.

Cast bullets are in my experience almost always a half to a whole thousands out of round, even expensive molds. Two or three thousands out of round is abnormal and cause for returning or rejecting or fixing the mold.

[ioon44]

As stated a bullet will also be sized by the barrel as it travels down it, the groups on paper is what matters.

I coat with HI-Tek and never have a leading problem.

[flyingrhino]

Just get a 452 sizer. That will make sure the max dimension is not oversized which will result in chambering issues. You will cast a few now and then that are a little on the large size if you don't have your mold closed tightly. Happens to me once in a while when I really get to cranking. At pistol distances you aren't going to see any accuracy problems.

[MUSTANG]

I would not be exceptionally worried about out of round in your application. I would look to see "Why?" they are out of round. Do you have a small piece of lead or grit trapped in a vent grove or other surface on one of the Mold Halves?

As another aside, at times one may intentionally enlarge the mold through a process called "Beagling a Mold". In essence you create a small shim that causes the mold to be held slightly open (.001, 002,etc..) resulting in a larger boolit when cast; but it also results in a slightly out of round projectile if the mold cast a "Perfect" boolit before hand. I've use the technique in a couple of .308, 30-40, and 30-06's that have slightly large bores.

A quick search using the site search resulted in this as the first result. There are many postings on CastBoolits concerning "Beagling".

http://castboolits.gunloads.com/showthread.php?78746-beagling-a-mold

[Lead Fred]

After sizing if they are out of round, we dump them back into the furnace.

[Soundguy]

Are the mold surfaces perfectly clean?

can you see any light thru them when closed?

[dverna]

"measuring anywhere from .448 to .456"

There is something wrong. Bullets should drop with much less variation than that. You have a mold issue or are not operating the mold properly.

Don Verna

[Soundguy]

.448 on a .452 mold is an underpour maybee. .456 is a mold not closed..

[44man]

Understand out of round. A mold expands funny so too hot makes boolits more out of round. Also smaller with more heat. Small amount will mean nothing at all. .001" out of round is common but get too hot and you will get smaller boolits. Mold heat is so important.

[ShooterAZ]

If it is a six cavity mold, keep your fingers off of the sprue plate handle.

[flyingrhino]

If it is a six cavity mold, keep your fingers off of the sprue plate handle.

What he said. That's exactly what I do wrong when I get to really cranking the pace and it results in an out of round bullet.

[hammer58]

Are the mold surfaces perfectly clean?

can you see any light thru them when closed?
No light is visible.

Sent from my SM-G920V using Tapatalk

[hammer58]

I think I found the problem. One of the guide pins is recessed about .020 of an inch. Looking at the base side of the bullets with the mold closed and the sprue plate open, you can see a small misalignment of the mold halves. I have added a couple of pictures so I hope everyone can see it.
Also, what do you guys use to clean the molds? http://uploads.tapatalk-cdn.com/20161108/cf4b613f802dca69c6339587b2db5229.jpghttp://uploads.tapatalk-cdn.com/20161108/b460cccd9785c2aba02e13313542c565.jpg

Sent from my SM-G920V using Tapatalk

[Soundguy]

I know they are lee, but those molds are usually mandrell swage formed and pretty darn exact. Small projectiles can be underpour, too large means the molds not closed completely.

[hammer58]

Also, I weighed a random handful of them tonight on a Frankford Arsenal digital scale, and they all weighed between 233.0 and 234.0 grains. Is this normal weight variation?

[scottfire1957]

I do not weigh them. Cast, powdercoat, size, load, shoot. I am, however, not a precision shooter.

I do not overthink this stuff.

[hammer58]

I do not overthink this stuff.

That is probably the way to go. It would save a lot of grief, but I am really interested in the science of it all. Keeps my mind off of politics:???:

[Ola]

I would bet OP is not a casting-robot, yet.

That'd explain the variation.

[Rattus58]

Generally speaking once you size your boolits they come back to round or certainly within allowable limits.In my opinion, you should always invest in the sizer of the your bullets optimum diameter if available. As far as out of round goes, one of my most accurate 50 caliber muzzleloader molds is out of round because of my "tampering" with it but lo and behold, even as cast, they seem to "shape up" while underway... this is with damn near pure lead of course.. so I don't know if this works with an alloyed metal. A sizer certainly, in my opinion, should take care of any out of round issues... but I do have a question...

How is it that you have such disparity in your mold? I can see excessive shrinkage if it got too hot, but then you're usually down in the pot when that happens so add some lead if you can't adjust the heat would be my suggestion and it should cool down enough and cast a slightly larger bullet. There may be other remedies available to you...

Ok... after reading more of this... I see the problem with the sizing disparities... :)


Much Aloha... Tom

[kungfustyle]

If you go with a Lee sizer, check the boolits with a micrometer. I had to sand out three of my Lee sizing die so they were sized properly. Best bet is to get into a rhythm them with casting. Temperature plays a big role both with the pot and mold. Get a thermometer and find out the temperature of the melt you are using. My Lee pot with the dial set on 6 will vary from 700 to 800 degrees depending on how full the pot is. Get the mold up to casting frosted bullets, set it on a damp towel to cool it down and cast about three or four rounds of bullets, cool, repeat. See if that helps with the variation. Use the same alloy the whole casting session, make ingots ahead of time. Try to just cast and save the spru till you are ready to take a break. Let it come back up to temperature before you begin again. If you dump a pile of spru back into the melt that will cool things down to 600 or so. 100 degrees on the melt makes a big difference.

[toallmy]

That's a lot out of round , when you finish casting next time leave the last pore in the mold but cut the sprue . Then after cooling check the size out of each cavity ( it may show you something ) . That is assuming you have checked the mold out good to make shore the blocks are clean and aligned properly . Possibly just preheating the mold to a even temp could help . Over size out of round could be a few things , but under size out of round is that's a problem .

[Soundguy]

I don't weigh mine either. alloy in the pot probably changes slightly throughout the day as I'm casting and adding in more metal, so some slight variation is to be expected.

[Soundguy]

If you dump a pile of spru back into the melt that will cool things down to 600 or so. 100 degrees on the melt makes a big difference.

That's why I dump my spru pieces back in after each drop. easier to keep uniform pace, right amount of time for mold temp to stay in sweet spot, etc.

[MUSTANG]

Also, I weighed a random handful of them tonight on a Frankford Arsenal digital scale, and they all weighed between 233.0 and 234.0 grains. Is this normal weight variation?


That weight differential (range distribution) is good. It's only a 1/2% variation. For cast rifle boolits; I sort all of mine into groups with each group varied by 1/10th grain measured on a Frankford Arsenal digital scale. The truth is it is somewhat chasing a level of distinction that is flawed since the same boolit weighed - then reweighed a little later on that scale will fluctuate on the 1/10th scale reading; but overall I get better accuracy by doing so. For pistol/revolver I would consider it a waste of time.

[hammer58]

I would bet OP is not a casting-robot, yet.



No doubt about that:lol:

[hammer58]

If you go with a Lee sizer, check the boolits with a micrometer.

Ordered a sizer today from Titan. I also corrected the pin depth and cleaned the mold.

I'll report again when I have had a chance to run some more boolits.

Thanks everybody!!