Seating Marks

[jetjock07]

Need advise on what to do. I’m currently loading for 22BR and I am getting marks on my bullets while seating. I’m using a Forster micrometer seater with necked down Peterson 6BR brass then expanding mandrel to give 2thous neck tension. It’s not a compressed load.

 

[918v]

Maybe your necks are too hard

 

[TSULLI]

Maybe your necks are too hard

Seating stem would be my guess. How bad are the marks? Is it causing physical damage to the projectile? Or is it just a slight difference in the shine of the copper? Unless it is causing some kind of damage or deformation and its not affecting consistency down range , I wouldn't worry about it.

 

[jetjock07]

Maybe your necks are too hard

Brand new brass

 

[jetjock07]

Seating stem would be my guess. How bad are the marks? Is it causing physical damage to the projectile? Or is it just a slight difference in the shine of the copper? Unless it is causing some kind of damage or deformation and its not affecting consistency down range , I wouldn't worry about it.

It’s putting a slight indentation in the bullet. Loaded several rounds with light load to break in barrel and now I’m about to start load development.

 

[BJames]

What bullet? Might need to switch to a VLD seating stem. I had that problem with Redding dies and a-tips, Berger hybrids, and eldm. Was physically damaging the bullets. Swapped out the seating stem and the problem went away.

 

[jetjock07]

What bullet? Might need to switch to a VLD seating stem. I had that problem with Redding dies and a-tips, Berger hybrids, and eldm. Was physically damaging the bullets. Swapped out the seating stem and the problem went away.

88 ELDm

 

[BJames]

Not sure if you’ve seen this or not, but hope it helps. Don’t worry, it’s not a pic of Barry, straight from the Forster site. https://www.forsterproducts.com/pdf/Troubleshooting Bullet Seating.pdf

 

[diggler1833]

^ "Can be addressed in most cases with improved reloading techniques".

Those 'improved reloading techniques' are mostly centered around the friction interference or neck tension. I'm of the belief that the seating stems on most Forester dies aren't optimally shaped for most bullets, and anything more than .002 is going to score the ogive quite a bit. Fortunately you can get custom honed stems if you want from Forester.

I had hellacious rings on my 6.5x47 cartridges (120 Scenar-L, 123 Scenar, 130 Norma, 130 ELD-M, and 130 Berger) using virgin brass until I used a .262 mandrel just prior to priming and charging...that cured ~80% of my problem. I still get a bit of a ring though.

Prior to that I was using the expander ball on the FL die and just running the case neck over that. I'd be willing to bet that the interference fit was in the .003 - .004 range with just the expander ball on virgin brass.

The good news is that even with essentially putting a Tubb nose ring on my bullets when I first started out, they still shot extremely well...as in no difference in accuracy out to 385 yards. I had multiple groups of 5 in the .2s during development, and my load data hasn't changed since I added the mandrel step either.

Might try a .0015 or .001 mandrel with that 22BR just for giggles.

 

[jetjock07]

Not sure if you’ve seen this or not, but hope it helps. Don’t worry, it’s not a pic of Barry, straight from the Forster site. https://www.forsterproducts.com/pdf/Troubleshooting Bullet Seating.pdf

I have not seen that. Looks like my two options are 1. Run a .001 under mandrel, or 2. Get a custom seating stem from Forster

 

[918v]

Brand new brass

You sized down from 6mm to 22.

 

[Mike Casselton]

I'll throw this out there too.
Did you chamfer and deburr the case mouth?

New brass usually requires additional seating force. That will be transmitted to your bullet where the stem contacts the bullet.

Have you tried this on a once fired case?

A properly fit seating stem will not mar the nose, so either way, I'd recommend replacing the stem or polishing out the little burr that causes the ring

 

[TSULLI]

Might need to switch to a VLD seating stem. I had that problem with Redding dies and a-tips, Berger hybrids, and eldm. Was physically damaging the bullets. Swapped out the seating stem and the problem went away.

You can go the custom route but I would guess that you would be served well with a vld seating stem as stated above.

Do I need VLD Seating Stems?

When loading a Very Low Drag (VLD) bullet or a hybrid bullet, we recommend that you use a VLD seating stem to ensure load consistency.

bergerbullets.com

30 second read and has a side by side comparison of a standard seating stem and a vld seating stem so you can see the difference in how the stem contacts the projectile. Big difference. The vld stem is designed to work with a secant ogive just like the eld-m

 

[spife7980]

Agreed, with all the above.
You worked the necks, anneal them.
Then chamfer and deburr them.
Then run a brush through them to wipe the annealing oxide stuff and then finally polish the seating stem with a few sacrificial bullets.

Some actual measurements of the sized and loaded neck dimensions would be beneficial as well if it’s just purely too much interference fit, aka “neck tension”

 

[Atomic_Lobster]

Can my um friend use the sacrificial bullets in his rifle

 

[jetjock07]

I'll throw this out there too.
Did you chamfer and deburr the case mouth?

New brass usually requires additional seating force. That will be transmitted to your bullet where the stem contacts the bullet.

Have you tried this on a once fired case?

A properly fit seating stem will not mar the nose, so either way, I'd recommend replacing the stem or polishing out the little burr that causes the ring

Brand new Peterson brass. Necked down expanded mandrel, then trimmed chamfered and deburred.

I have not tried fired brass yet.

 

[Lawnboi]

Brand new Peterson brass. Necked down expanded mandrel, then trimmed chamfered and deburred.

I have not tried fired brass yet.

Fresh Annealed necks are very abrasive. Run that mandrel through with a wet lube or wax, I rub imperial on the rim, then dry tumble it.

You can feel the outside of the brass on a new case, that annealed area feels abrasive. The above method will smooth it out enough to make the first loading go much smoother.

I fought this for a while before figuring it out. Dry lube also dosnt work for crap in this application.

A perfect seating stem can mask the issue but really the problem is the brass is too grabby before you get some carbon in there.

 

[918v]

Brand new Peterson brass. Necked down expanded mandrel, then trimmed chamfered and deburred.

I have not tried fired brass yet.

But you sized down from 6mm to .22 which has the same hardening effect as if you fired and reloaded them.

 

[Bigfatcock]

Dropping brass from the annealer into a citric acid solution knocks all scale off.

Polish out the seating stem, or use epoxy to create a custom profile in the stem.

 

[jetjock07]

You sized down from 6mm to 22.

Correct

 

[918v]

Correct

That’s why you have excessive seating effort.

 

[918v]

A bullet will be harder to seat into a hard neck set to .002” tension vs a soft neck. The harder the bullet is seating the bigger the mark on the bullet nose. I never had to lap any seating stem.