Advice needed with marks on neck

Mc Fraser

Well-Known Member
Joined
Jul 23, 2018
Messages
386
Location
Calgary, AB
Hello,
What could cause the marks on the neck? I can see them in almost every round, I have 8 of them loaded.

300WM 200 gr ELDX the pictures are from the same bullet.
Norma brass 1F, annealed and run though Forester seating and bushing bump neck sizing die. RCBS RC IV press, measured 2 thou runout, round never chambered.

TIA
 

Attachments

  • 20200328_210126.jpg
    20200328_210126.jpg
    468.3 KB · Views: 310
  • 20200328_210209.jpg
    20200328_210209.jpg
    531.2 KB · Views: 308
  • 20200328_210242.jpg
    20200328_210242.jpg
    222.7 KB · Views: 315
  • 20200328_210254.jpg
    20200328_210254.jpg
    194 KB · Views: 294
  • 20200328_210305.jpg
    20200328_210305.jpg
    141 KB · Views: 274
I get those too. The bushings are causing it. I ignore them because they cause no harm and don't seem to affect accuracy. You can lube each neck before sizing, then wipe them off after seating
 
I have had those at times - came from little tiny bits of brass building up and sticking to edge of the mouth of the bushing.

When looked at with a magnifying glass, it looked like the bushing was defective.

Soaking overnight in bore solvent removed it. A bit of lube on the case necks from time to time prevented it from coming back.
 
Below is a bushing that had embedded grit inside the bushing and then started picking up brass. If nothing is done more and more brass builds up and it can cause more and deeper scratches. The bushing below had been polished with 0000 steel wool and what you see is what was not removed. Meaning the embedded grit is still there and will just start picking up more brass.

Any copper bore cleaner will remove the brass and its strength will determine how long it takes. So use a bore cleaner that curls your nose hairs and makes your eyes water when you sniff it to remove the brass. Next take a snug-fitting bore mop and apply some J&B bore paste, automotive rubbing compound, Mothers Mag and Wheel polish, etc and polish the bushing or die. This will remove the embedded grit and polish the bushing or die.

This is a common problem on full length dies if the neck shoulder junction is not polished correctly at the factory. Then this rough area starts picking up brass and starts scratching the case neck.

LyFIQbw.jpg


Below a factory polished Forster full length die as a comparison.

vEmboge.png


P.S. CatShooter old buddy, if you didn't buy cheap bore cleaners you wouldn't need to soak the bushing all night............................Bazinga! :)
 
P.S. CatShooter old buddy, if you didn't buy cheap bore cleaners you wouldn't need to soak the bushing all night............................Bazinga! :)


I use Captain Morgan's Spiced Dark Rum... clean the bushings over night, and drink what is left in the morning. :))))))))
 
Below is a bushing that had embedded grit inside the bushing and then started picking up brass. If nothing is done more and more brass builds up and it can cause more and deeper scratches. The bushing below had been polished with 0000 steel wool and what you see is what was not removed. Meaning the embedded grit is still there and will just start picking up more brass.

Any copper bore cleaner will remove the brass and its strength will determine how long it takes. So use a bore cleaner that curls your nose hairs and makes your eyes water when you sniff it to remove the brass. Next take a snug-fitting bore mop and apply some J&B bore paste, automotive rubbing compound, Mothers Mag and Wheel polish, etc and polish the bushing or die. This will remove the embedded grit and polish the bushing or die.

This is a common problem on full length dies if the neck shoulder junction is not polished correctly at the factory. Then this rough area starts picking up brass and starts scratching the case neck.

LyFIQbw.jpg


Below a factory polished Forster full length die as a comparison.

vEmboge.png


P.S. CatShooter old buddy, if you didn't buy cheap bore cleaners you wouldn't need to soak the bushing all night............................Bazinga! :)
BAZINGA I love that show big bang theory sad it's done
 
Following along...

so on these dies with superficial scratches; is it feasible to polish with lapping compound to smooth it out? I've experienced these as well, but have yet to clean/replace the bushing. There's a reason I lurk here- to get answers & you guys always surprise me with things I don't know- THANK YOU!
 
Warning! This thread is more than 5 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.
Top