Seating Die Marking Bullets

[bigedp51]

Your bullet is only touching on the seater mouth. You want the seater to also to touch the bullet tip, meaning you need the seater to fit the shape of the bullet.

Below the bullet is seated to the proper depth before the bullet is crimped. If the bullet is not seated to the proper depth before it is crimped, you will leave a ring around the bullet.

 

[bearhunter]

Your bullet is only touching on the seater mouth. You want the seater to also to touch the bullet tip, meaning you need the seater to fit the shape of the bullet.

Below the bullet is seated to the proper depth before the bullet is crimped. If the bullet is not seated to the proper depth before it is crimped, you will leave a ring around the bullet.

So how do you explain the ring when there is no crimp???

I do agree though that the tip and ogive contact should be happening at the same time, with a bit more contact on the tip.

Ogive contact should be minimal and maybe, IMHO, non existent.

 

[B]

You want as much contact as possible. With pistol bullets I don't feel it matters much where that contact is. You really shouldn't have to modify anything to load 9mm with that equipment. If his seating die is set low enough to begin or finish a crimp before the bullet is seated that could explain it but with the photos and info presented that doesn't appear to be a factor.

 

[Sniffer]

You want as much contact as possible. With pistol bullets I don't feel it matters much where that contact is. You really shouldn't have to modify anything to load 9mm with that equipment. If his seating die is set low enough to begin or finish a crimp before the bullet is seated that could explain it but with the photos and info presented that doesn't appear to be a factor.

Have to agree with this. Pretty sure my seater is marking the bullets at least in part due to the fact that all the force required is being focused on a small thin area.

If that same force were spread across a larger area (ie across the entire bullet) I doubt there would be any marks.

 

[tigrr]

Could the crimp force be starting before the bullet is fully seated. That would leave a mark from the seating stem having to increase force to seat the bullet.
So I would back off the seating die a smidge and insert the bullet seating stem a smidge. Keep doing that till it stops marking the bullet.

 

[Sniffer]

Could the crimp force be starting before the bullet is fully seated. That would leave a mark from the seating stem having to increase force to seat the bullet.
So I would back off the seating die a smidge and insert the bullet seating stem a smidge. Keep doing that till it stops marking the bullet.

I might be misunderstanding but I assume you are referring to a combined seating / crimping die?

I have never used a combo type die, I seat then crimp in two separate steps.

 

[bigedp51]

Bullet Seating Advice — How to Avoid Ring Marks on Your Bullets

https://bulletin.accurateshooter.com/2016/05/bullet-seating-advice-how-to-avoid-ring-marks-on-your-bullets/

 

[cokelon]

I had the same issue with Lyman dies, their solutions was for me to sand/polish inside of the die a bit. I told them off and returned it because I should not have to do something like that to a new product. I went with Dillon Dies for my xl750 and no issues there.

 

[Sniffer]

Update.

I have been limping along with this (had a TON of loaded ammo that I finally finished) so I figured I would try to fix it up.

I chamfered the seating stem a little and that helped (could still see the mark but it moved closer to the tip of the bullet and was less noticeable) so I went all out.

Took some metal epoxy type stuff I had kicking around and filled the seating stem with it, then shaped it to fit my bullets. Left it overnight and tried it today.

Zero marks on the bullets now which indicates that the issue was down to all the force being applied to a small area on the outside edge of the seater stem where it made contact with the bullet. When the force was spread over a larger area no more problem.

If this hadn't worked I was gonna pick up a Mighty Armoury 9mm seating die with Delrin insert (they have two different inserts - one for round nose bullets and one for flat nose / HP bullets). I still might pick up one of these but for right now this fix is working great.

 

[Canuck65]

Excessive neck tension is your problem. Your expander die or your process may be the culprit here, not the seater.

 

[kewp]

I have had the same rings on a couple different calibers that I load . Went with the polishing the seating stem method . I used a lathe , seating stem in the lathe chuck , bullet in the tail stock with valve lashing compound . Couple minutes and problem gone

 

[Sniffer]

Excessive neck tension is your problem. Your expander die or your process may be the culprit here, not the seater.

My experimenting suggested this was not the issue.

I tried flaring the case mouths more (went to comical lengths which just aren't practical to see if the marks would disappear and they did not).

 

[Quiet]

As mentioned, setting the belling die lower should be the first step. Next, sorting your brass to choose softer makes (like Rem headstamp) can often solve this without requiring permanent modification to the parts of your die set.

 

[Sniffer]

My experimenting suggested this was not the issue.

I tried flaring the case mouths more (went to comical lengths which just aren't practical to see if the marks would disappear and they did not).

As mentioned, setting the belling die lower should be the first step. Next, sorting your brass to choose softer makes (like Rem headstamp) can often solve this without requiring permanent modification to the parts of your die set.

Tried that. Didnt work.

I load ~20,000 rounds of 9mm a year so sorting brass isn't something I plan to do. The permanent die modification seems to be filling the gap pretty well.

 

[Janeau]

It has do do with the seating stem configuration..nothing else.. modify or replace.