Issue Seating 9mm Bullets

[Crowcifier666]

I'm having problems when seating MBC's 124gr Small Ball 9mm bullets. I used to load on my RCBS Rockchucker Supreme, with no problems, but have since set up an old Lyman All American turret. I'm using a Lyman bullet seating die. Since switching to the turret it appears the die is shaving lead off the projectiles.



I am belling the neck generously with a Lyman powder thru expanding die. All bullets are seating consistently to equal depth. The issue seems cosmetic, really, and doesn't seem to affect performance, but it kind of bugs me.

Could the issue be slop in the turret? All components are the same except for the press used.

 

[LiveLife]

If you are using sufficient amount of flare and seating/taper crimping in the same step, I would decrease the amount of taper crimp to not shave the bullet.

Since MBC bullets are sized .356", I would use .377"-.378" taper crimp.

.356" (bullet diameter) + .011" (case wall thickness) + .011" = .378" (taper crimp)

 

[Crowcifier666]

Thanks, but the bullets are shaving upon seating. I taper crimp separately, so the crimp has no impact.

I'm inclined to believe that it's either that the bullet seating die is somehow off (still new to this), or the turret holding it has slop (none felt, seems solid).

Leaning towards the older, used, turret, as the sourceof the problem; because I had no issues with my NIB Rockchucker single stage.

 

[LiveLife]

It can't be the seating die because you used the same die with the single stage press without shaving the lead.

Are you using same or different shell holder?

Perhaps the turret is tilting during operation?

Can you measure any turret deflection with and without ram force applied during operation to tilt turret relative to shell plate to seat the bullet at an angle?

 

[Tilos]

I would try the seating die in a different turret position to see if it still shaves the bullet.
The mis-alignment could be in the indexing mechanism for the station you use to seat the bullet.
I'm not familiar with that press, but most modern indexers have some amount of float for self alignment.
Does that scrape always show up in the same spot/position (12,3,6,9 o'clock)?
jmo

 

[sl33py]

I had the same issue with some coated lead bullets, and it was simply not belled/flared sufficiently.

I would argue that it does impact function -did you case gauge those? Mine wouldn't seat fully in my case gauge as the lead buildup on the case lip did impact that seating area. Usually easy to scrape off with a fingernail or knife, and then they seated properly.

Can you take a pic of the bullet after it seats but before it crimps? So it still has the bell/flare? I also like the idea of trying a different position to see if it's misalignment!

GL!

 

[rcmodel]

I don't think it can have anything to do with case mouth bell.
Because the scraping is well above the case mouth.

I think the seating die is screwed down too far and the end of the taper crimp section is scraping coating & lead off the bullet.

Try unscrewing the die about 1 1/2 turns, then run a good loaded round in it and then lock the lock ring.
That will center the die.

Then, screw the seating stem down a like distance to get the correct OAL again.

You probably had it adjusted correctly when it was in the RCBS, but now it's adjusted to deep in the Lyman.

rc

 

[Crowcifier666]

Thanks gents, lots of good input. I like Tilos' idea of trying a different turret location.

RC, I will try readjusting the die, though I'm almost positive I adjusted it when I moved it to the turret. Your diagnosis sounds legit. Is it possible that the die and press aren't compatible? I do remember it being seated really low in the threads on the turret.

Sl33py, I will try and post some pics you requested this week.

Appreciate the help!

 

[Tilos]

I don't think it can have anything to do with case mouth bell.
Because the scraping is well above the case mouth.

I think the seating die is screwed down too far and the end of the taper crimp section is scraping coating & lead off the bullet.

Try unscrewing the die about 1 1/2 turns, then run a good loaded round in it and then lock the lock ring.
That will center the die.

Then, screw the seating stem down a like distance to get the correct OAL again.

You probably had it adjusted correctly when it was in the RCBS, but now it's adjusted to deep in the Lyman.
rc

Good call, die body UP, seating stem down.
You can see a ring on the ogive where the stem is pushing the bullet, and it kind of lines up with the scrape.

Edit: There could be something in the shell holder groove, that keeps the case from centering, or even the wrong holder.

 

[TimSr]

Quote:
Originally Posted by rcmodel
I don't think it can have anything to do with case mouth bell.
Because the scraping is well above the case mouth.

I think the seating die is screwed down too far and the end of the taper crimp section is scraping coating & lead off the bullet.

Try unscrewing the die about 1 1/2 turns, then run a good loaded round in it and then lock the lock ring.
That will center the die.

Then, screw the seating stem down a like distance to get the correct OAL again.

You probably had it adjusted correctly when it was in the RCBS, but now it's adjusted to deep in the Lyman.
rc

Good call, die body UP, seating stem down.
You can see a ring on the ogive where the stem is pushing the bullet, and it kind of lines up with the scrape.

^^^^x3

 

[scythefwd]

^ x4

 

[Crowcifier666]

Thanks gents, I took rc's advice and backed the die out a bit and no more shaving!

Rcmodel, thank you for being so generous with your knowledge, this isn't the first time you've solved one of my conundrums. You are a great asset to this forum.