Problem with RCBS 308 Seater Die

[CLP]

I started loading 308 recently. When seating bullets into cases (sized, trimmed, chamfered, deburred, and belled), the seater plug leaves circumferential marks on the bullet about a third of the length down from the meplat. I disassembled the die, cleaned it, and rubbed the seater plug mouth down with 0000 steel wool thinking maybe a burr or sharp edge was causing it. It made no difference. I'm not sure if it's only cosmetic or will affect accuracy and precision- I haven't shot any of them yet. It's affected bulk 150g BTFMJ, Hornady 150g SST, and Sierra 168g HPBT Matchking. Anyone seen this before?

 

[medalguy]

Never seen this on rifle bullets but you're right, it's from the seater plug. Contact RCBS and talk to their customer service folks. I'll wager they will send you another plug and stem at no cost.

 

[rcmodel]

Or, use a Craytex tip in a Dremel tool and polish the sharp edge off.

If you don't have a Dremel tool?
Chuck the stem in a drill and use black emery paper wrapped on a small dowel rod.

All you need to do is get rid of the sharp edge.

Also, make sure your die isn't set so low it is crimping the case before the bullet is fully seated.
That will foil the best seating stem in the world!

Also, chamfering the sharp edge inside the case mouth will make seating easier.

rc

 

[Strongbad]

Happens on a couple of my seaters... it's more cosmetic than anything else. You can polish it off if you want, but it's nothing I'd be overly concerned about.

 

[CLP]

Yeah, not crimping at all, it's backed out properly and lock nut is then tightened. I crimp with the Lee FCD

 

[joneb]

I chucked my seater in a drill press and used 600 grit wet/dry sand paper to ease the sharp edge.

 

[Zane]

I've noted this with my RCBS dies. When I take an extra second to make sure that the bullet is truly vertical and seat a touch more slowly, the rings disappeared. It adds about 2-3 seconds per bullet. It seems to happen more with the Hornady than with Sierra.

 

[Walkalong]

Polish it like rcmodel suggested. It will stop leaving the marks. They won't hurt anything, but it is nice not to have them there.