Scratches on case

Ideal Tool · October 30, 2010, 10:52 PM

Hello Guys, I have a question I haven't seen posted before..When sizing rifle brass, I usually neck size, or partially full-lengh size if I don't have neck-sizing die, there are fine scratches sometimes left on case walls. Now these are not very deep..can;t really feel them with fingernail..but they are there. I usually take die apart & using 400-600 wet/dry paper polish them out on bench lathe..but this only lasts so long & their back again..I wonder if that isn,t caused by brass sticking to die walls? As they are mirror bright inside with no visible scratches. I am using good lube's..Corbin swaging lube, & Imperial. If I keep this up, I'll wear those suckers out! I even notice it with my carbide pistol dies. What do you guys think? Do they hurt anything besides looks? Am I being too fussy? Thanks guys!

lll Otto lll · October 31, 2010, 12:12 AM

Generally speaking, almost all instances of case scratching can be traced to foreign material that becomes imbedded in/or adheres to the inside surfaces of the die itself.

Go here: http://www.redding-reloading.com/tech-line-a-tips
Click on "Scratched Cases: Causes and Cures"

Jim243 · October 31, 2010, 02:16 AM

What are you using for media for cleaning your cases?? Tumbler?

wncchester · October 31, 2010, 06:20 PM

"..I wonder if that isn't caused by brass sticking to die walls?"

Exactly so. It's called galling. It occurs when dry soft metals adhere to harder metals under sliding friction and pressure. It starts harmlessly at the microscopic level but, once started, the bits will continue to collect brass from each case so it grows. Unless it's cleaned and removed (as you already do) the cases will be damaged. (I do lapping but I will eventually try plugging one end of the die and soaking the chamber over night with a copper solvent bore cleaner like CR-10.)

With case hardened steel rifle dies it's almost impossible to imbed anything in them; dies are as hard as files! So, it's galling or nothing.

Lapping dies with super fine grits of black silicon carbide papers, 400 to 600 grits seem to be perfect, as does the 3M green Scotchbrite pads your wife uses to clean pots and pans. It would take a LOT of such lapping to measurably change the dimensions of sizer dies. You do not need to mirror polish the interiors after lapping, a soft matt surface holds case lube better and that makes sizing effort easier!

Carbide sizer rings do exactly the same thing as steel and it can easily be corrected the same way with no fear of changing the carbide ring...unless you use a diamond grit!

Prevention of galling is better than correction. All you really need to do is make sure your case necks get a thin but complete layer of case lube. I've had virtually NO galling problems since I started applying Imperial lube with my finger tips as I pick up each case. Lightly lubing occasional pistol cases - maybe 1 in 10 - usually prevents galling on carbide and makes the sizing effort almost unnoticable.

Ideal Tool · November 1, 2010, 03:31 PM

Hello, guys, and thanks for input. I clean cases after each firing in vib. tumbler, using corn-cob grit With Flitz. The stuff is new. Every case is lightly coated with Imperial or what works even better for tough sizing/swaging Corbin lube. I have even went so far as wiping case necks with clean cloth befor lubing. I think Wncchester is right about galling as I don't think it is grit doing the scratching. Thanks again.

t45 · November 1, 2010, 06:51 PM

I had the same problem a few months ago and traced it back to having dust or some type of foreign material embedded in my lube pad. It must have picked it up from a few pieces of dirty brass. Just a thought.

demigod · November 2, 2010, 08:03 AM

A little dust on the brass from the media indeed. Shoot em up!!

Edward Horton · November 2, 2010, 08:40 AM

Just use J&B bore paste and Kroil or Iosso bore cleaner and a shotgun cleaning mop of the correct diameter chucked in a drill and polish the die clean. Make sure you wipe the cases off after coming out of the cases tumbler-vibrator to remove the cleaning compound off the outside of the cases. Clean or replace your lube pad and do not reload during sand storms.

F. Guffey · November 2, 2010, 09:14 AM

and I use a towel on a dowel to clean dies. When using white towels I have never had one come out clean the first pass.

Finish? After an engine has a 100,000 ++ miles on it and the pistons are removed most reach for the hone, the hone is used to remove glaze? and create cross hatches. I can not improve on the cylinder finish when it is as smooth as glass without taper, so I apply the leaver policy, I leaver the way I founder.

Embeddable, of the two materials the brass case is embeddable, the die is not.

Sizing without lube, the case stick in the die, if it got hot enough to gall the reloader would need a fire extinguisher and gloves to handle and or cool cases then there is annealing, I suppose a reloader could get into mortal combat with the press when sizing and create heat, but, a stuck case would slow down the process long enough for the equipment to cool.

And then I am thinking of those machine guns, the ones the cases are fired in that stretch, now there is some fast in and out without lube, no galling of the case.

F. Guffey

chiefr · November 2, 2010, 09:33 AM

I too have had this same problem and agree that some foriegn material transferred from the case to inside my sizing die. I was given some used dies that had this problem and was able to polish the scratches out.
One of my other hobbies is auto restoration and I used the same procedure used in restoring stainess trim. 1000 to 2000 grit alum oxide wet sanding and water. followed up by 3M extra fine compound. I used a wooden dowel with a slit as a drill pilot to hold the sand paper. Took some time, but it worked.

F. Guffey · November 2, 2010, 12:24 PM

happened to me or something like that. I had a Winchester Model 70 in 300 Win Mag, I shot it, then called Winchester, they said I had to shoot it some more, I explained to them the chamber was too rough, to long and too large in diameter, they said I had to shoot it, I then took it to their warranty shop and explained to them the problem, I ask them what they were going to do to correct the problem, they said they were going to polish, shine hone, and etc. the chamber, then I ask how was any of that going to reduce the size of the chamber, there response, gotta do it, those are the instructions, I went to pick up the rifle, the warranty shop said the chamber was too larger, I then ask it it came in that way or was it something they did, the response, the rifle came in with a big chamber, now it is bigger, the rifle went back to Winchester and things got uglier.

If the die and or chamber has a scratch and or gouge in it and then the gouge or scratch is polished, honed and or what ever out..... no, I do not see how anything stayed the same size or got smaller.

If the die is that bad send it back to the manufactured, do not tell them an elephant stepped on it, I have used that excuse, they could cut the chamber to clean it up and then shorten the die, something like Winchester should have done with my barrel.

F. Guffey

October 30, 2010, 10:52 PM	#1
Ideal Tool Junior member Join Date: October 6, 2010 Location: Michigan Posts: 1,080	Scratches on case Hello Guys, I have a question I haven't seen posted before..When sizing rifle brass, I usually neck size, or partially full-lengh size if I don't have neck-sizing die, there are fine scratches sometimes left on case walls. Now these are not very deep..can;t really feel them with fingernail..but they are there. I usually take die apart & using 400-600 wet/dry paper polish them out on bench lathe..but this only lasts so long & their back again..I wonder if that isn,t caused by brass sticking to die walls? As they are mirror bright inside with no visible scratches. I am using good lube's..Corbin swaging lube, & Imperial. If I keep this up, I'll wear those suckers out! I even notice it with my carbide pistol dies. What do you guys think? Do they hurt anything besides looks? Am I being too fussy? Thanks guys!

October 31, 2010, 02:16 AM	#3
Jim243 Senior Member Join Date: January 5, 2009 Location: Just off Route 66 Posts: 5,067	What are you using for media for cleaning your cases?? Tumbler? __________________ Si vis pacem, para bellum

October 31, 2010, 12:12 AM	#2
lll Otto lll Senior Member Join Date: June 1, 2008 Location: Lone Star State Posts: 295	Generally speaking, almost all instances of case scratching can be traced to foreign material that becomes imbedded in/or adheres to the inside surfaces of the die itself. Go here: http://www.redding-reloading.com/tech-line-a-tips Click on "Scratched Cases: Causes and Cures"

October 31, 2010, 06:20 PM	#4
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	"..I wonder if that isn't caused by brass sticking to die walls?" Exactly so. It's called galling. It occurs when dry soft metals adhere to harder metals under sliding friction and pressure. It starts harmlessly at the microscopic level but, once started, the bits will continue to collect brass from each case so it grows. Unless it's cleaned and removed (as you already do) the cases will be damaged. (I do lapping but I will eventually try plugging one end of the die and soaking the chamber over night with a copper solvent bore cleaner like CR-10.) With case hardened steel rifle dies it's almost impossible to imbed anything in them; dies are as hard as files! So, it's galling or nothing. Lapping dies with super fine grits of black silicon carbide papers, 400 to 600 grits seem to be perfect, as does the 3M green Scotchbrite pads your wife uses to clean pots and pans. It would take a LOT of such lapping to measurably change the dimensions of sizer dies. You do not need to mirror polish the interiors after lapping, a soft matt surface holds case lube better and that makes sizing effort easier! Carbide sizer rings do exactly the same thing as steel and it can easily be corrected the same way with no fear of changing the carbide ring...unless you use a diamond grit! Prevention of galling is better than correction. All you really need to do is make sure your case necks get a thin but complete layer of case lube. I've had virtually NO galling problems since I started applying Imperial lube with my finger tips as I pick up each case. Lightly lubing occasional pistol cases - maybe 1 in 10 - usually prevents galling on carbide and makes the sizing effort almost unnoticable.

November 1, 2010, 03:31 PM	#5
Ideal Tool Junior member Join Date: October 6, 2010 Location: Michigan Posts: 1,080	Hello, guys, and thanks for input. I clean cases after each firing in vib. tumbler, using corn-cob grit With Flitz. The stuff is new. Every case is lightly coated with Imperial or what works even better for tough sizing/swaging Corbin lube. I have even went so far as wiping case necks with clean cloth befor lubing. I think Wncchester is right about galling as I don't think it is grit doing the scratching. Thanks again.

November 1, 2010, 06:51 PM	#6
t45 Senior Member Join Date: January 29, 2010 Location: Foothills, NC Posts: 782	I had the same problem a few months ago and traced it back to having dust or some type of foreign material embedded in my lube pad. It must have picked it up from a few pieces of dirty brass. Just a thought.

November 2, 2010, 08:03 AM	#7
demigod Junior member Join Date: March 13, 2008 Location: AZ Posts: 1,129	A little dust on the brass from the media indeed. Shoot em up!!

November 2, 2010, 08:40 AM	#8
Edward Horton Junior member Join Date: October 12, 2009 Posts: 70	Just use J&B bore paste and Kroil or Iosso bore cleaner and a shotgun cleaning mop of the correct diameter chucked in a drill and polish the die clean. Make sure you wipe the cases off after coming out of the cases tumbler-vibrator to remove the cleaning compound off the outside of the cases. Clean or replace your lube pad and do not reload during sand storms.

November 2, 2010, 09:14 AM	#9
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	and I use a towel on a dowel to clean dies. When using white towels I have never had one come out clean the first pass. Finish? After an engine has a 100,000 ++ miles on it and the pistons are removed most reach for the hone, the hone is used to remove glaze? and create cross hatches. I can not improve on the cylinder finish when it is as smooth as glass without taper, so I apply the leaver policy, I leaver the way I founder. Embeddable, of the two materials the brass case is embeddable, the die is not. Sizing without lube, the case stick in the die, if it got hot enough to gall the reloader would need a fire extinguisher and gloves to handle and or cool cases then there is annealing, I suppose a reloader could get into mortal combat with the press when sizing and create heat, but, a stuck case would slow down the process long enough for the equipment to cool. And then I am thinking of those machine guns, the ones the cases are fired in that stretch, now there is some fast in and out without lube, no galling of the case. F. Guffey

November 2, 2010, 09:33 AM	#10
chiefr Senior Member Join Date: January 27, 2010 Location: AR Posts: 1,401	I too have had this same problem and agree that some foriegn material transferred from the case to inside my sizing die. I was given some used dies that had this problem and was able to polish the scratches out. One of my other hobbies is auto restoration and I used the same procedure used in restoring stainess trim. 1000 to 2000 grit alum oxide wet sanding and water. followed up by 3M extra fine compound. I used a wooden dowel with a slit as a drill pilot to hold the sand paper. Took some time, but it worked.

November 2, 2010, 12:24 PM	#11
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	happened to me or something like that. I had a Winchester Model 70 in 300 Win Mag, I shot it, then called Winchester, they said I had to shoot it some more, I explained to them the chamber was too rough, to long and too large in diameter, they said I had to shoot it, I then took it to their warranty shop and explained to them the problem, I ask them what they were going to do to correct the problem, they said they were going to polish, shine hone, and etc. the chamber, then I ask how was any of that going to reduce the size of the chamber, there response, gotta do it, those are the instructions, I went to pick up the rifle, the warranty shop said the chamber was too larger, I then ask it it came in that way or was it something they did, the response, the rifle came in with a big chamber, now it is bigger, the rifle went back to Winchester and things got uglier. If the die and or chamber has a scratch and or gouge in it and then the gouge or scratch is polished, honed and or what ever out..... no, I do not see how anything stayed the same size or got smaller. If the die is that bad send it back to the manufactured, do not tell them an elephant stepped on it, I have used that excuse, they could cut the chamber to clean it up and then shorten the die, something like Winchester should have done with my barrel. F. Guffey