mysterious longitudinal grooves on case necks

[tcr1146]

Still using the old fashioned method of rolling on an ink pad using RCBS lube. When I neck size, I use my fingers to make sure the neck gets adequately lubed. By the way, all the cases that have the "grooves/scratches" were sized and shot by the previous owner. thanks, Tom

 

[Dusty Stevens]

This is very common and doesnt really cause a problem its just a looks thing.

 

[Brians356]

This is very common and doesnt really cause a problem its just a looks thing.

I have a half dozen Redding bushing dies, and at least two dozen different bushings (mix of plain and TiN). If it's common, how come I've never seen it? I'm never that lucky. I've sized dry and with mica, but not with wet lube.

 

[Hntndad]

This is very common and doesnt really cause a problem its just a looks thing.

I agree. When sizing, keep an eye on the condition of your brass. Insufficient case lube causes galling. Newly annealed necks also can cause galling as well. When I notice the slightest hint of galling on my case necks I will take the die/bushing and chuck up a bore mop with a little flitz and polish it out. Doesn't take much. I keep dies clean.

 

[Dusty Stevens]

I think its embedded carbon in the bushings. The only time i see it is with tin bushings on br cartridges that may not be cleaned often during a match. Like htndad said a little flitz or iosso on a bore mop will straighten it right out if it bothers you. Or you can call bud mundy and get a carbide bushing.

 

[smoooth]

I just took care of my RCBS FL die that was marking up the necks (previously mentioned) using a bore brush and some 0000 steel wool on the end of it, chucked in the drill about 20 seconds on high. Cleaned the die, lubed a case and no more lines on the necks. Suppose it is possible that just a thorough die cleaning could have solved the problem, too, but I am pleased with the quick result.

 

[Mozella]

Still using the old fashioned method of rolling on an ink pad using RCBS lube. When I neck size, I use my fingers to make sure the neck gets adequately lubed. By the way, all the cases that have the "grooves/scratches" were sized and shot by the previous owner. thanks, Tom

Well, in that case it doesn't matter what you're doing, it matters what the previous owner did. I would guess he put the necks into a bushing without lube.

 

[1newmexkid]

I used J-B's bore-bright on my bushings. Works great.

 

[lpreddick]

Still using the old fashioned method of rolling on an ink pad using RCBS lube. When I neck size, I use my fingers to make sure the neck gets adequately lubed. By the way, all the cases that have the "grooves/scratches" were sized and shot by the previous owner. thanks, Tom

if this was mentioned, i missed it: bushings must float inside the die. if they are tight they can be off center. i was getting neck scratches recently in spite of floating the bushing. a tin redding bushing is extremely hard so i don't think we can "grind" and surface away but we can polish them. i did this with this one bushing, but still got some scratches(deburred the hell out of the case mouth also). i was concerned the die itself might now be perfectly centered, so i put a rubber washer under the lock ring(lee rings have a washer under them normally), annealed the cases and 4-0 steel wooled the annealing residue off the neck(gritty stuff inside the neck also), and ran it thru the bushing...smooth and SHINEY, not a mark any where. don't know if its the washer but i using it. problem here is the die is a type s fl bushing type and pushing the shoulder back with the washer is slightly tricky, but well annealed brass sizes easily. agree the scratches are cosmetic, but i want my brass to be prettier than an khardashian.

 

[LHSmith]

I think its embedded carbon in the bushings. The only time i see it is with tin bushings on br cartridges that may not be cleaned often during a match. Like htndad said a little flitz or iosso on a bore mop will straighten it right out if it bothers you. Or you can call bud mundy and get a carbide bushing.

That's my experience also. Once you use carbide bushings you'll never go back. They are available in 1/2 thou increments.....but the size selection is very limited. If carbide is not available, I had better luck with Wilson's steel bushings.TiN is much over-rated IMHO.

 

[Gaffshot]

Die is dirty and scratching the necks. Clean or replace. Happens to regular FL dies and bushing dies.
http://www.redding-reloading.com/tech-line-a-tips-faqs/149-scratched-cases-causes-and-cures

 

[Shaggy357]

If you haven't seen the tiny scratches in the case necks, or even down the case itself, then you are extremely regimented in case prep, cleaning, and die cleaning, or you haven't loaded much. One of the worst causes is dirty tumbler media. Folks pull out the shiny brass and assume it is clean. Dirt and carbon get in their lube and die. After a few trips to the loading bench, dirty dies leave scratches on the cases. Also seen with the loader who comes in from the range and sizes the cases before cleaning them. Carbon build up in the die. Automotive brake cleaner, computer compressed air cans and similar tips have helped me resolve a lot of this. Takes seconds to clean the die, wipe and blow dry at the end of the reloading session so clean when used next time. Brass rod, 0000 steel wool, Flitz, and hand drill can be your friend when polishing up die buttons an inside die walls. Gotta clean out all the residue tho.....fleece scraps from the fabric store work well for twisting up into the dies to help clean and/or dry. Even does nice job in getting any crud out of the threads......somebody was sizing with a dirty die, or dirty brass. Keep it all clean, and you likely wont get the scratches. Not saying dies dont have rough spots or that die bushings can't have burrs. That is possible, but usually results in scratches limited to one area of the case, not all the way around. Just another opinion to throw in the pot....

 

[powderbrake]

I recently had the problem of scratches on my 6BR necks as I was loading with my Redding Competition neck sizing die with a Redding TiN bushing. After about 50-60 cases it started to scratch the necks, I cleaned the bushing ( even though I have viewed it under a microscope and could not see any inclusions) and started loading again, and 50 rounds later the same problem.

I had never had this problem before with my 22-250, or my 223, which both had the same die setup. These were brand new, unfired 6BR cases, which I had trimmed on my Giraud trimmer. Then I thought, could it be tiny pieces of brass from the trimming?.

I tumbled the new, trimmed 6BR brass to clean off any trim dust, and proceeded to load 400 cases with NO problems..Note to self.......ALWAYS clean after trimming.

 

[6brnube]

This is very common and doesnt really cause a problem its just a looks thing.

I have to agree. I have been getting them on 6br lapua brass since day one. No amount of US, tumbling, and or hand cleaning has any effect.

Trimmed case or not - always "vertical" lines

Steel bushing, .003" neck tension - always "vertical" lines
TiN coated bushing, .001" neck tension - No vertical lines

It's a no turn chamber and honestly I'm not the world greatest shooter, so I can only share observations.

I cannot claim one way or the other on accuracy effects. I'm still too much of a variable in that equation, but I DON'T see any signs that I can pick up to indicate problem.

 

[6xcshooter]

Lack of lube will do this. What lube are you using? Are you sure you properly lubricated your test cases?

+1 this helped me put more lube around outside of neck and keep inside of die clean