lead shaving when seating

First topic message reminder :

I may have a mismatch between dies and bullets.

Magnus BNWC flat base #802
Winchester brass - once of twice fired
Lyman M-1 expander die
Redding micrometer seating die
RCBS Rockchucker

Brass is expanded to the point that half the rear driving band easily sits in the case.   I check the bullet is sitting straight and then press it home.  Every 4th to 5th round gives a sliver of lead around the edge of the case.  It does not happen as often with the Magnus #802, but still occasionally.

I tried lowering the expander button in the die body and went too far - as the outside of the stretched brass was then rubbing on the body of the seating die and giving a polished ring on the tip of the case.   I backed off a bit at a time, so now I know it is expanding as much as possible without rubbing in the seating die, but the slivers still occasionally show up.

I am guessing the sliver comes off the bottom edge of the rear (later edit;  I wrote rear when I meant to write front) driving band as the case mouth moves over that square edge.  It is always attached firmly and takes fingernail and rag to break it free.

1) will these slivers leave the driving bands damaged to the point of impacting accuracy?
2) anyone had a similar occurrence?
3) suggested steps to avoid it?

Thanks

Ian

Ian / (Federal/Papa) John,
If you want to try this solution, I'll be happy to ship you necessary components:
http://www.photoescapeinc.com/products/single-stage-powder-die-kit.html
http://www.photoescapeinc.com/products/powder-funnel.html

John,
I know you are using Star.  I don't have solution for that, however above would work for single stage if you have one.  I believe, the key here is proper case expansion.  Thus if you have single stage, you can size and then expand cases beforehand, and then finish loading on Star.  You would need to back off your sizing/depriming die.

Alternatively, Bruce Williams probably can turn custom expander plug.  I can provide design & dimensions for tip of the plug.

AP

AP,

LOL, good use of "Papa John"/"Federal John". That goes back a few years with my friend Dave Wilson. You missed "Popcorn John".

I am using a Star, and this thread has provided much food for thought. I have some next steps to try based on the discussion here. The biggest eye-opener for me was that it's possibly (or likely) shaving off of the forward driving band. I was thinking base; that now sounds wrong.

So I have some things to look at. For one, I increased my bell/flare, and now I believe it's way too much, based on discussion here. I also will pull some bullets to see if I can determine where the shavings are coming from.

Again, thanks to all for the open discussion. It's helpful, even several years later!

john bickar wrote:AP,

LOL, good use of "Papa John"/"Federal John". That goes back a few years with my friend Dave Wilson. You missed "Popcorn John".

Nah, I didn't miss that one.  I believe, that came from you planning to send 2000 cases of 32L to Dave, and then trying to trade it for RR I believe, Dave called you on that - "NO TRADES!"  Anyway.......

Based on my experience with 38 HBWC lead shaving comes from any part of the projectile hitting edge created by case flaring.  No matter how much belling I tried, lead shaving stubbornly didn't want to go away.  The only options here is cylindrical case expansion for the OD of the bullet (- 0 / - 0.001") for the length of seating, or using harder alloy for projectiles.  Later wasn't an option for 38 HBWC, so I experimented (somewhat successfully) with hard cast DEWC, resulting in two different PTUs.  Same approach is transferred to 45.

Working hard on my shooting hobby!  Another 19999 of hours to go Going to test few "rubber bands" tomorrow.

AP

Soooooo ....

I've got the same problems with Redding dies. the case dragging in the seating die on the flare. Hadn't given it any thought as being the root cause of the shaving until reading about it here in the last couple weeks. And with the tools I need to possibly fix it 5 minutes from where I sit, like an idiot, I left the dies and brass 1700 miles away ...

Anyway, if Photoescapes parts can be modified to work with the Star press, and John's interested in experimenting, I'm up for the challenge.