Lop-sided/uneven sizing - causes and prevention?

[mtnman31]

As pictured below, what causes lop-sided or uneven sizing? i.e. one side of the bullet gets its driving bands sized down while the other side remains untouched. I see this with a few different bullets designs that I cast for.

The example below is the Lyman 358432 WC. I am using an RCBS sizer with RCBS sizer die and Lyman #344 top punch (flat face for WC's). The uneven sizing is not consistent with relation to the size die. For example, it is not always oriented on the front side or back. It happens all around and is not consistently in one spot. The bullets are plain wheel weights and they drop from mold at .3595 and are being sized down to .358.

It does not seem to make a noticeable difference in bullet performance but, then again, I have only been shooting these as plinkers and not for extreme accuracy. Nonetheless, aesthetics are important when a person is striving for casting perfection...

Any help is greatly appreciated.

7650

[ktw]

The boolit is not properly aligned with the die. The correct top punch will help correct that.

Assuming there are no alignment issues with the sizer ram. If that is the problem RCBS should take care of it for you.

Sizing them nose first is another solution. This is one of the reasons the Star sizer and the Lee sizer dies are popular. You can do this with the RCBS/Lyman sizers by removing the die punch and the punch return parts below it from the sizer, run them through nose first with a flat top punch to size, re-assemble sizer, then run them through again base first to lube.

-ktw

[59stude]

I have had the same problem with some boolits when they was casted too big, like Lee 358-150 swc that drops .364 from the mould with my hard alloy ( 4 parts ww+ 1part lino + 4% tin ).

What I did was open up an Lee .357 push throu ( sp?) die to .360 and size them there first, then size and lube them again in my Lyman.

Going from have about 50 % of the boolits uneven sized to about 1 % with this extra step of work, I can live with, and it saves tear and wear on my Lyman 45 also.
Now I need to buy more Lee sizing dies to modify for my other calibers I have.

To all of my friends of the best internet site in the world,
have an nice week-end and a lot of shooting.

59stude

[monadnock#5]

I'm with ktw, it'a a misalignment problem. By the Lyman mould chart in Castpics, you should be using the 429 top punch.

[HeavyMetal]

Even with the right nose punch you may still have this problem, just to a lesser degree.
In the stickies is a thread about re aligning (?) sizers.

To be honest I've never opened it so have no idea how much info or how good it is BUT you should!

Again I went with a Star, mostly for production reason, but this never happens with a Star in good condition.

[IcerUSA]

Looks like what my 450 does and mine has a ram problem . I've made a new ram for it but I think the casting is worn also and I don't have a reamer close to that size to rebore the casting .
I use that one for a GC seater or for some of the larger boolits as long as it is just a few of them .

Keith

[hiram]

Does it happen if you use a different die in the same 450? Does it happen with the same die in a different 450?

[Boomer Mikey]

Even with the right nose punch you may still have this problem, just to a lesser degree.
In the stickies is a thread about re aligning (?) sizers.

To be honest I've never opened it so have no idea how much info or how good it is BUT you should!

Again I went with a Star, mostly for production reason, but this never happens with a Star in good condition.

The reason the Star and Lee sizers don't do this is that the boolits are sized nose first. If you used a flat base nose punch with the Lyman and sized nose first the boolits will be round and true.

The old; two step, sizing dies shaved lead off one side of boolits as well. Newer dies have a tapered entry that helps align boolits better. If the die's center pin (the "I" part of an H&I die set) isn't raised up high enough to set the boolit on a flat surface before entering the die (short up-stroke) the boolit can be cocked to one side or the other even if the nose punch is centered on the boolit. The old trick of letting the nose punch "float" in the ram with a dab of bullet lube holding it there and the set screw loose will worsen the issue.

Lower the ram and check how much front-to-back and side-to-side play there is. If you have access to a lathe or a friend with one; make a long, flat base nose punch +0.0000" -0.0005" to fit the sizing die inside diameter and within +0.0000" -0.0005" of the ram's nose punch hole. Use this die alignment fixture to check ram/die alignment. It'll be easy to see which way the alignment is off... loosen the die lock-down nut and lower the ram with your alignment fixture into the die then tighten the lock-down nut to align the die with the ram. This method should be used when installing any die with the nose punch you're going to use.

Some nose punch shank - ram nose punch mounting hole alignments are a pretty sloppy causing boolits to be sized more on one side than the other or result in the boolit being "cocked" to one side during the sizing process. Sizing the boolits nose first with a flat base nose punch then lubing the boolits with the normal nose punch "floating" will usually produce superior results with the Lyman and RCBS push-pull sizers. The Saeco sizer is made to tighter tolerances, and with Saeco's superior die design, boolits sized in Saeco push-pull sizers are usually true.

Boomer :Fire:

[mtnman31]

I checked the play on my ram using a dial indicator and magnetic base. No measurable movement. The ram can rotate in the base a little bit. I put a top punch in and rotated the ram back and forth and got only around .001 movement as measured on the top punch. The sizer press is almost new so I don't expect the problem to be a worn or loose fitting ram.

I tried sizing the 358432 with both a flat faced top punch and the #429. It was actually worse with the #429. Maybe the flat faced TP allowed the bullet to center itself up as it was starting into the sizing portion of the die?

I have noticed that the problem always seems to be much worse when sizing wad cutters, SWC's and other flat pointed bullets. The round noses seem to more or less self center when the top punch is pressed down. I never have any problems sizing 358311's and 358242's in the same size die.

I did find that the problem can be lessened, though not eliminated, by adjusting the return (up stroke) of the "I" piston in the die. I adjust it to return to just where the placing of a fresh unsized bullet into the die just meets the sizing portion of the die. That way, when the ram is lowered the base of the bullet has little room to move and is more or less started right at the point where it is getting sized.

I did try nose first and it all but eliminated the problem. I tried it with just a few WCs but didn't have any SWC cast up at the time. I don't want to rely on that method because it is doubling the work. A Star sizer may come in the distant future but, for now, I have both a Lyman and RCBS sizer and most of the dies and TPs I need. I really can't justify the purchase of an entire new sizing system.

[HeavyMetal]

Some times it's tough to justify changing things.

However lets knock a few ideas around shall we?

First if you put both your current sizers on e bay you should net $100.00 each, maybe a little more if you put some sizing dies with each one.

a good used Star is selling in the $195.00 to $225.00 range on e bay. In this case your trading up by spending your cash a second time!

The gain is simple better bullets= better targets= more fun and less work!

Some of the forum is experimenting with a reduced cost sizing die for the Star's. it looks good and I will be testing a prototype soon as will some others. If this works out die costs will not be any more than what you've been paying for the Lyman/ RCBS dies and you'll be getting better boolits.

The real cool part of nose sizing is two or three base punches , that are flat, will do almost every boolit you cast! Granted some specialty boolits will require some special technique's but that will be true of any sizer system!

I currently have two Star's. I had what you have for sizing and it sucked but I didn't want to spend the money. At last I was so frustrated I pulled the trigger and bought my first Star NEW. Afterwards I spent three days wondering why I had never none this sooner!

It's been 19 years since the first Star was purchased, in retrospect I should have done it 35 yrs ago! I have never looked back and I have never been disapointed in the Star.

Not trying to tell you what to do, just relaying the fact that my life would have been a lot easier a lot sooner had someone given me the same scoop in 1977!

[ktw]

It's not necessary to spend Star money to size nose first, particularly if you are shooting handgun bullets at moderate velocity. The Lee sizer dies and a bottle of Alox will run you less than $15 a pop.

-ktw