Scratch my neck

[Link]

I must have picked up a little hard carbon after annealing. My necks have light scratches. I can remove the scratches with a slight turn with steel wool. I cleaned the bushing with JB, no help. I guess I will buy another bu. If I had a nitrate bu instead of steel maybe this wouldn't have happened?
OH WELL. ;{

 

[alf]

Use a brass brush wrapped with 0000 steel wool chucked in a drill, a little Flitz on it won't hurt either.

 

[Leeman]

Are you sure it's not from oxidation on the surface of the necks after annealing? It's reported quite often and I also experienced it. Now I just tumble the cases in corn/rice after annealing before any other operations and don't get any scratches on the necks during sizing.

 

[Webster]

I must have picked up a little hard carbon after annealing. My necks have light scratches. I can remove the scratches with a slight turn with steel wool. I cleaned the bushing with JB, no help. I guess I will buy another bu. If I had a nitrate bu instead of steel maybe this wouldn't have happened?
OH WELL. ;{

Examine the bushing with a magnifying glass, you should be able to see anything that would cause a scratch. Any tiny burrs of brass on the neck o.d. opening get dislodged and dragged down the neck.

You must lube the necks when sizing some guys don't. The neck is the most heavily sized part of the case. It only makes sense to lube it.

I used steel bushings for 30 years without a problem. I don't think an expensive nitrided bushing will help. The scratches have to be created by particles being dragged down the neck.

If the bushing is clean and the case neck is chamfered clean and lubed you shouldn't have a problem.
Possible high points or particles.
1. Junk adhering to the bushing. Easy to verify.
2. Neck o.d. not chamfered. Easy to check
3. Junk on the neck surface. Clean and size.

 

[divingin]

I clean bushings (when necessary) by wrapping a small strip of 800 grit sandpaper around a bore mop. put a bit of oil on it, and spin it for a few seconds with a power drill.

For me, scratches are usually caused by deposited brass, usually after trimming and chamfering. I suspect grit and carbon from sizing cases generally get pushed out of the way rather than adhering to the bushing, though that's just a guess.

 

[Webster]

I must have picked up a little hard carbon after annealing. My necks have light scratches. I can remove the scratches with a slight turn with steel wool. I cleaned the bushing with JB, no help. I guess I will buy another bu. If I had a nitrate bu instead of steel maybe this wouldn't have happened?
OH WELL. ;{

Take the top of the die off and look for copper adhesions in the neck area from galling. If there is Cu it's probably caused by not lubing the necks.

 

[Fire Dog]

I will also add from my own experience, that using either of the the two “Dry” neck lubes commonly available, I have had them scratch and do permanent damage to neck bushings that fortunately I was able to remove {I stopped after the second case} with the same trick that divingin uses, a bit of {in my case} 1’220 grit wet/dry paper rolled into a tube and lubed with a dash of BoreTec.
Now, perhaps 0.0005” larger.
My opinion is that the ceramic balls used to suspend the dry lubricant are shedding particles or are already in the mix when they are dropped into the jars.
The scratching only started when I used the dry lube and never before those two cases and never again once I went back to a whisper of Imperial Die Wax and now Ballistic Case wax…

 

[PhilC]

I will also add from my own experience, that using either of the the two “Dry” neck lubes commonly available, I have had them scratch and do permanent damage to neck bushings that fortunately I was able to remove {I stopped after the second case} with the same trick that divingin uses, a bit of {in my case} 1’220 grit wet/dry paper rolled into a tube and lubed with a dash of BoreTec.
Now, perhaps 0.0005” larger.
My opinion is that the ceramic balls used to suspend the dry lubricant are shedding particles or are already in the mix when they are dropped into the jars.
The scratching only started when I used the dry lube and never before those two cases and never again once I went back to a whisper of Imperial Die Wax and now Ballistic Case wax…

Am glad you posted this as I'm experiencing the same thing in my Forster sizing die after switching to dry neck lube. I can polish the scratches off necks with 4/0 steel wool but is a PITA to do. Going to toss the dry lube.

 

[Fire Dog]

Am glad you posted this as I'm experiencing the same thing in my Forster sizing die after switching to dry neck lube. I can polish the scratches off necks with 4/0 steel wool but is a PITA to do. Going to toss the dry lube.

I suggest that you will now have to try and smooth out either the bushing if it is a bushing die or the neck area of a standard die as the scratching will now have put problems in that area of the die. I used 1’200 grit wet & dry rolled into a tube along with a bit of paint thinner though perhaps a copper solvent would be a help as there may be embedded brass as well as the metal of the bushing/die neck.

 

[PhilC]

It's a non-bushing benchrest die. Tried polishing a die once before and didn't go well so for the $9 Forster charges I'll let them do it.