neck turning to remove high spots

[TackDriver284]

It's my first time turning necks to clean up high spots and minimize runout. I purchased the K&M and using the power drill to neck turn. I have read the instructions and a few links on the net. I just have one question. I read that you need to use a full sizing die to be able to size all the way to the shoulder because a bushing sizing die won't be able to. There will be a possible doughnut at the bottom of the neck where it meets the shoulder if I do not use a full sizing die ( non bushing). Is that correct? Of course after sizing I use a mandrel before neck turning. Then after neck turning run the cases through a tumbler and neck size it after. If I am doing it wrong, please let me know. Thanks for any advises.

 

[Darkhorse]

I do it this way and have done it like this for over 20 years. I use the Forster Original case trimmer with the outside neck turning accessory.
http://www.forsterproducts.com/product- ... cessories/
I work in batches, so the first thing is to full length resize with a standard RCBS FL sizeing die.
Then trim to length any case that needs it. Deburr as usual.
Then turn the necks to where approx. 85% of the case neck is cleaned up. I adjust the cutter to just blend with the radius of the case shoulder.
As far as I'm concerned the case is ready for use. I don't see where the tumbler operation is of any use at this point.
The case is already FL resized so why does it need to be neck sized?
This is the neck turning process I use with my equipment as part of my case prep process. I don't know anything about your choice of neck turning equipment so things may be a little different.
Don't overthink the process, all we are doing is removing excess material from the case neck.

 

[TackDriver284]

The case is already FL resized so why does it need to be neck sized?

After running the case through a mandrel, it opens the diameter of the neck to neck turn, so after neck turning you need to resize it back to the original diameter to seat bullets, full or neck size, correct? Which is best?

 

[jimbires]

a bushing die WILL NOT size the neck completely to the shoulder . yes you want to cut complete neck and touch into the shoulder barely . remember you are removing material from the neck. your die will not size the neck as small as it used to . if you're using a std sizing die you should be ok . if using a bushing die you'll probably need a smaller bushing . after cutting , I'd probably size at least the neck again , it's hard to say what size it is after the process . the case body should be fine . it doesn't take any longer though to full resize . be sure to clean your lube out of the cases after cutting the necks , so you don't harm the primers and powder .

 

[TackDriver284]

a bushing die WILL NOT size the neck completely to the shoulder . yes you want to cut complete neck and touch into the shoulder barely . remember you are removing material from the neck. your die will not size the neck as small as it used to . if you're using a std sizing die you should be ok . if using a bushing die you'll probably need a smaller bushing . after cutting , I'd probably size at least the neck again , it's hard to say what size it is after the process . the case body should be fine . it doesn't take any longer though to full resize . be sure to clean your lube out of the cases after cutting the necks , so you don't harm the primers and powder .

Before I made the post above, I remembered running the 6.5 Creed brass through a Redding neck sizer and when I ran them through the mandrel, it had very little resistance. Then on the turner the cases had a slight looseness or little wobble. So this morning I went out on my reloading table and ran a few 7 Magnum brass through a full sizer die, no bushing, and it had a lot more resistance on the mandrel, of course I used Imperial wax lube, then when put the brass on the turner rod guide, it fit like a champ, it did not have the looseness or wobble like the 6.5 Creedmoor brass had. The cuts were smoother and I figured that the full sizer die brings the neck back to SAMMI specs and the tighter fit on the mandrel pushes all the variances and doughnuts outside and you shave that off. It's my first time using the neck turner, so I need to learn my mistakes from it. Here is the pic of the cut the first time, does it need more cut into the shoulder?
http://imgur.com/a/bmWJR

 

[Darkhorse]

The case is already FL resized so why does it need to be neck sized?

After running the case through a mandrel, it opens the diameter of the neck to neck turn, so after neck turning you need to resize it back to the original diameter to seat bullets, full or neck size, correct? Which is best?

My Forster does not open the diameter of the neck after trimming or turning. I can go straight to charging and bullet seating. Maybe it's a difference in our equipment.
I would blend the shoulder cut so it's hard to tell where the cutter stops and the shoulder begins.

 

[jimbires]

it's a little hard for me to tell in the picture but yes , I think you need to cut a little closer to the shoulder . I can cut close enough to the shoulder that I get a slight scrape or scratch on the shoulder . try not to cut into the shoulder , the necks could be weakened enough to come off . like darkhorse said , you want to blend the cut into the shoulder . yes , you want a snug fit , no wobble on the mandrel . your cut looks a little rough , try feeding the case a little slower . you've got the idea just a little practice and you'll be fine . hold a piece of steel wool against your cut when finished . this will help polish your cut .

 

[TackDriver284]

Thanks, little mistakes I have learned from and learn from those with knowledge.

 

[257 Ackley]

I use FL bushing dies for most of my varmint and all my competition rifles. Some guys only neck size until chambering a round becomes an issue, but I prefer a .002 shoulder bump after each firing.

On new (unfired) brass, run a mandrel through the neck to open it up to fit on your turning mandrel (both should be from the same manufacturer). Some turn after the initial firing if they are forming a wildcat cartridge, (or turn to create a false shoulder) but most will turn prior to the initial firing. Don't take too much off with each pass. You are better off taking several passes than to try and take it all off at once. Do you know the measurements of your chamber? That can affect what you decide the necks need to be turned down to as well. You want .002 - .003 clearance around the loaded round inside the chamber. That allows the bullet to have a good release without the neck area being over-worked. What you are looking for is even neck tension all the way around.

A doughnut only becomes an issue if you are seating the bullet that far down in the case. Doughnuts have nothing to do with what kind of sizing die you use. I usually only find a problem with doughnuts when a parent case is reduced in size IE, 6BR to 22BR. You sometimes need to go a little further into the shoulder to take some of the "thickness" out of that area. Some guys use an inside neck reamer to remove doughnuts as well, but there are mixed results on how effective that is.

Early days of neck turning were done with a cordless drill, but found that the runout in the drill was not good enough for my needs. I went to this for all my neck turning: http://www.benchrite.com/cscart/index.p ... t_id=29789

Combined with an accurate cutting tool like PMA makes: http://www.pmatool.com/neck-turning-tools/ will give you really consistent, concentric brass. It's a big investment, but if you are looking at making tiny groups, it is important.

Not sure what the tumbling after turning is for. If you are trying to remove cutting oils from the brass, just use one-shot or similar lube on the inside of the neck and there will not be a need to tumble. You received good advice from Darkhorse on making sure all cases are trimmed to length prior to starting the neck turning process. They all need to have the same starting point.

 

[TackDriver284]

Thanks guys, really good information. Now to begin my little mission.