How oval is too oval? Does it REALLY matter??

[Semaj]

I have been casting for about three years now. I started with a lee 200 gr .450 conical mold for my 1851 navy, and recently started casting for my 45-70 with the lee .457-405. My mold blocks aren't perfectly aligned giving me a size of .455 at narrowest and .464 at largest. I know round is ideal, but I cast some up last night and a few I selected for testing grouped in one hole at 30 yards. I don't size yet as I pretty much just got started with serious casting and reloading. Any thoughts?

[Larry Gibson]

If you don't shoot farther than 30 yards your oval bullets are doing well. It really doesn't take much to properly aligned the mould blocks....then you wouldn't have the problem......just a suggestion.

[mdi]

I've found mold temp. and melt temp. to affect "roundness" of the bullet. Experiment with hotter mold temps. and cooler mold temps. Same with alloy, it may have a big difference. Keep notes so you can repeat good results...

[Semaj]

If you don't shoot farther than 30 yards your oval bullets are doing well. It really doesn't take much to properly aligned the mould blocks....then you wouldn't have the problem......just a suggestion.

I've taken a few shots at 100 yards, and am getting -1.75 inch group. Maybe they are coming to round in the barrel? No leading either. As for the mold, the blocks are slightly off. There is a definite ridge on the parting line, the halves are a few thou out of alignment. How would I go about fixing?

[tazman]

With groups that good, I am not certain I would want to mess with it. It might get better, it might get worse.

[Semaj]

Taking the advice from a pm, I am filling in some details I should have mentioned. The mold is a new production lee, when the mold is closed without any finagling, the pins catch on the block, there are no burrs that I can detect, and the inner face is free from lead. As far as I can tell, the mold is out of alignment by shifting fore and aft at the parting line, like two half-circles that aren't properly centered.

[lightman]

By my math thats .009 out of round. To me thats excessive. I would tinker with the mold a little bit and try to get that corrected. Your groups are good so maybe you should not change anything! Not doing anything would bother me, wondering how much better round bullets would shoot.

[Walter Laich]

believe it or not Lee has been known to make less than perfect molds!!! yes, I know, how could that be??

two thoughts:

call and send it back -- it gets you a good one (hopefully) and is a way to tell them their QC is off

most barrels will round out the slug as you shoot it through it. The ability to chamber the round comes into play here as far as what too oval

[Larry Gibson]

Semaj

I've taken a few shots at 100 yards, and am getting -1.75 inch group.

How many is a "few", specifically in the "group"?

Maybe they are coming to round in the barrel?

If you are sizing the bullets then you are rounding them except for the nose. However, even if you're not sizing then they are conforming to the roundness of the barrel. Given the slow twist your 45-70 probably has and the probable low velocity (you don't mention either the velocity or the rifle used in?) the difference won't be apparent until a longer range is used.

No leading either. As for the mold, the blocks are slightly off. There is a definite ridge on the parting line, the halves are a few thou out of alignment. How would I go about fixing?

A couple pictures would help us see the problem with the mould blocks to see if there is a fixable solution? There really isn't any need to use bullets from a mould .009" out of alignment when most block alignment problems are easily fixed. If not then as suggested the mould should be returned to Lee.

[Shopdog]

Probably shouldn't respond,oh well.

I've found,the more perfectly round the CB,the better.To the point that what seems like inconsequent parting lines may not play a role,they do,on paper.I swage pretty much all target CB's.Would really have to think of a good reason not to?Hunting is a slightly different story,but...not much.They're swaged to better define sharp metplats....vs target fodder where the ogive consistency has more emphasis.Obviously,the better the mould,the easier it is to achieve.The swaging process adds some other concerns....moreso if the mould blocks aren't up to snuff.Best of luck with your project.

[vzerone]

If your mould is out of alignment and you can move it fore and aft ,when it's closed and the handles are gripped firmly, then either the alignment pins aren't protruding enough, the female holes in the other block have are too large or a combination of these and the pins and holes aren't where they should be. I'd send it back to LEE with a note.

It's funny I'm hearing more of this same problem with their new design moulds then I did their older style.

[Cosmic_Charlie]

I recently had a Lyman mold with that issue. Even after sizing, i could feel that seam through the case neck on a loaded round. Sent it back to Midway and ordered a RD mold from Accurate.

[fredj338]

Yet another reason I size my bullets. IF they are slightly out of round the sizer makes them a uniform size. There is a reason that custom mold makers are generally better than buying Lee.

[gwpercle]

One of the reasons I size my boolits is to make them round...much easier than trying to come up with a perfectly round casting mould (which may be Unicorn in nature) ...the second reason is to lube them and the third reason is to seat and crimp gas checks.
I love my Lyman 450...
Gary

[Grmps]

Semaj Welcome to CB

Pictures will be helpful, what you think your saying may not be what we are hearing :).
The easiest way I've found to post pictures is through Imgur

Posting pictures using IMGUR

1 Go to https://imgur.com/
Select sign up
Fill out information or register with: facebook, twitter, Google+ or Yahoo account
Log into your account
Select new post, upload image, browse, select your image from your computer and click open
Hover mouse over your chosen name (top right toolbar) and select images
Left click on the image you want to post
Then click on COPY next to [BBCode (message boards & forums)]
Go to the post you want to put the image in, either right click and select paste or hit [Ctrl + V]
Save your post and you're done.

Other options
http://castboolits.gunloads.com/showthread.php?344661-Capturing-amp-Posting-screen-shots

If, when holding the mold fully closed you can move the 2 sides then you alignment pins are not seated deep enough.

Allignment pins can be tightened by clamping the mold to a solid surface the using a punch drive the pins snugly into the receiving holes.
This is an aluminum mold so don't force things.

[Cosmic_Charlie]

3 out of the 4 molds I've ordered drop nice round bullets. Never really checked them for ovality because measuring them on the seam would not give an accurate representation. But that Lyman mold was definitely defective, exhibiting the anomaly even after sizing. Bullets shot fine at 100 feet though, ten going into about 3" shooting off hand ( 30-30 rifle). Maybe I was being too fussy by sending it back?