Help with a sizing issue?

[boatswainsmate]

Hi All,
I'm having a issue with the bullets from my new mold sizing differently on each side of the bullet. I made RCBS aware of my issue and I sent them my old die for investigation. They sent me a brand new die back at the only the cost of shipping!!!! Unfortunately the new die is doing the same thing the old die was doing:-? Does anyone have any suggestions? Thanks in advance.
http://i306.photobucket.com/albums/nn271/ericlee1971/img_0212_zpsc0d4d09c.jpg (http://s306.photobucket.com/user/ericlee1971/media/img_0212_zpsc0d4d09c.jpg.html)

[mozeppa]

how much off are they?

[HATCH]

I am a little confused.
So you are saying that the boolit isn't round after sizing?
Did you check it before sizing?

I doubt its a problem with the die

[boatswainsmate]

The first bullet shows where the lead is being pushed up into the crimp grove. The second shows a low ridge and the other two show a uniform sized area. I just sized (500) 45 kt's with the same sizer with no issues.

[boatswainsmate]

So I have a possible out of round bullet?

[Dusty Bannister]

What top punch are you using for this bullet? Is it seated tight in the ram, or left a little loose to float.

[boatswainsmate]

I'm using the top punch that came with the mold. The top punch is seated tight in the ram.

[725]

I'd just shoot 'em. See how they fly.

[RobS]

Looks like to me that your boolit is being pushed down off center from above as it is pushed downward into the sizing die. This can happen with lubrisizers like RCBS, Lyman and Saeco when the ram is off center or becomes loose from use etc. I had the same problem and until I one day get a Star I continue to use a Lee push through sizing die first and come back with my RCBS lubrisizer. One thing that can help if you have a flat meplat is to use a flat bottom top punch so the boolit can move a bit as it enters the sizing die however I was still having a little off center sizing. Another trick as mentioned would be to NOT tighten down the set screw on the top punch and put a bit of lube on the bottom of the top punch so it stays stuck to the ram but free floats a bit.

[HATCH]

Just wondering if you shot them yet?

[boatswainsmate]

Thanks for all the advice. I guess I will load some to see how they shoot.

[runfiverun]

I think it's your mold.
we use sizing dies to insure the boolits is at least that small.
if it touches some of the boolit and not some then the boolit is rounder than when it went in.

it looks like you are sizing on the parting line on each of the boolits.
I'd double check that the mold is closing properly and fully.
then measure the other way on the boolits, you may need to open the mold a little through lapping or cleaning to get them a tick more round.

[243winxb]

Sizing down more than .003" ? Whats the diameter of the bullets as cast? What diameter are you sizing too?

[boatswainsmate]

The bullets are measuring .3599 as cast according to my micrometer. I'm sizing them to .357. Thanks

[44man]

Near imposable to get a round boolit from most molds. Usually larger at the parting line. Never seen it affect accuracy. Shoot them.

[Calamity Jake]

I'm using the top punch that came with the mold. The top punch is seated tight in the ram.

The top punch could be causing the issue.
Remove the top punch and put a little lube on the stem to hold it in place in the sizer, it will float around a little
and center itself better.

[boatswainsmate]

I have sized some more bullets in different ways with all the advice I have been given. I placed a line down the center of the bullet and sized them in different postions in the die. The first set of pictures is with the top punch set tight. The order is two bullets with the line centered in the back and right side (pic 1) and left side and front.(pic 2)
The third and fourth pictures are the same order with the top punch held in with bullet lube. Thanks again for all the advice!
http://i306.photobucket.com/albums/nn271/ericlee1971/img_0224_zps0cb699d1.jpg (http://s306.photobucket.com/user/ericlee1971/media/img_0224_zps0cb699d1.jpg.html)
http://i306.photobucket.com/albums/nn271/ericlee1971/img_0223_zps00f5f380.jpg (http://s306.photobucket.com/user/ericlee1971/media/img_0223_zps00f5f380.jpg.html)
http://i306.photobucket.com/albums/nn271/ericlee1971/img_0222_zps0a23d14d.jpg (http://s306.photobucket.com/user/ericlee1971/media/img_0222_zps0a23d14d.jpg.html)
http://i306.photobucket.com/albums/nn271/ericlee1971/img_0221_zps48f7b08d.jpg (http://s306.photobucket.com/user/ericlee1971/media/img_0221_zps48f7b08d.jpg.html)

[Dusty Bannister]

Does it appear that in photo #1 that the two bullets on the left have a clearer mark left on the surface that the others in Photos #1 and 2? It is hard for me to see if the width of the bands are affected. Perhaps a different camera angle. Bo'sun, what are you seeing in actuallity? Are the original castings round by your micrometer measurement? Out of round would show uneven band width on the sides if sized round.

[MtGun44]

Perfectly round boolits are a nice goal, but in reality, way overrated for real
world stuff like accuracy. Shoot a set of 3 groups of hand selected for "worst case"
and another set of 3 groups hand selected for "best case".

Unlikely to be different group sizes on the average.

Bill

[boatswainsmate]

Does it appear that in photo #1 that the two bullets on the left have a clearer mark left on the surface that the others in Photos #1 and 2? It is hard for me to see if the width of the bands are affected. Perhaps a different camera angle. Bo'sun, what are you seeing in actuallity? Are the original castings round by your micrometer measurement? Out of round would show uneven band width on the sides if sized round.
It appears that smear is happening on the back right side of the bullet. I measured the front and rear driving bands on the seperation line and 180 degrees to it. I got the following measurements. Front driving band .3586 and .3590. Rear driving band .3580 and .3600. Thanks for your time