Neck Sizing Depth?

Apex Custom Rifles

Official LRH Sponsor
Aug 2, 2009
Southern MN
I have been reloading for about 4 years and just got into neck sizing the last year. I talked to a few guys that use to shoot LR competition and they said that back in the day they would just neck size with enough tension to just barely hold the bullet in place, and they would run the bullet into the lands.

I don't shoot competition yet, and failed to ask how far down the neck do you run the die. I have been only running it down about 2/3 from the mouth of the neck.

How far down you you guys run your dies on the necks 1/2, 2/3 all the way?
You don't say what kind of competition your friends shot and that matters. Such minimal sizing and soft seating might be useful in BR matches and single shot rifles. It's not practical anywhere else tho.

There is nothing to be gained by neck sizing below the base of the seated bullet.
I don't have a short answer of the length to neck size. Just some observations from 10 years of LR loading.

Full length sizing just bumping the shoulder is what I do for everything I load where accuracy matters. I use neck sizing dies in addition to FL dies in cases where a standard full length die with the expander ball removed does not provide enough neck tension on turned cases.

At "some point" neck sized only cartridges need to have the shoulder bumped as they will get too hard to chamber. Not a good thing to have happen during a competition. Then when you do change this variable by periodically full length resizing, how can you be sure the load will perform the same as it did when it was neck sized only? Full length everytime removes one variable.

Clean polished neck contacting surface, lots of neck tension, and bullets sitting in the lands have been a good rule of thumb for me. You can tell if you are doing everything right if you pull some bullets.

Bullet pullers: Found the $20 RCBS press mounted with collets best after some preparation. First thing you have to do when you get a collet is run emery paper between the slots to break the sharp edges of the slots. Clean it with gun scrubber and then chuck up the bullet you will be using in a drill and hone it using JB bore paste. Clean it again and try it. If it leaves lines in the bullet do it some more. Now you have a bullet puller that you can actually use the bullets that you pulled.... for barrel foulers and first round sighters of course.

Pull the bullets that you currently have loaded. If they look as they did in the box you are in good shape on your necks. If you can see where it has been seated in the case by digs and scratches, your necks aren't clean or smooth enough for consistent neck tension. I run a 7 wsm that has bullets that are held by 110 thou. I carry them in my shirt pocket while hunting. Lots of neck tension. I never could get the light neck tension to work well for me, ES is too high.

Good luck.
You don't say what kind of competition your friends shot and that matters. Such minimal sizing and soft seating might be useful in BR matches and single shot rifles. It's not practical anywhere else tho.

There is nothing to be gained by neck sizing below the base of the seated bullet.

He was a BR shooter @ 2-300 back in the early 60's back in the earlier years of BR shooting. He still makes custom rifles and shoots today but not in competition. He has many true "One Hole groups" to his name at 100 yards, meaning one hole the diameter of the bullet.

I always use to FL size my brass, but thought I would try the neck sizing to try and get a little more life out of my brass. On my Ruger MkII with hart #4 barrel custom, I am on my 4th firing with winchester brass with one FL sizing and 3 neck sizing operations performed. They are still chambering very well.

I don't shoot competition, I would like to in the near future, but as for now, I just use my rifles for punching paper and hunting. My last session with my .243 I shot a 5 shot 0.813 group @ 200 yards with neck sized winchester brass, nosler 95gr BT's and 38.5gr 4350 and CCI LRBr.

My custom 7mm Mag shot 0.374" @ 100 last time out. P-17 Enfield full custom, Douglas XX #7 barrel, timney trigger, fully trued, richards microfit stock, shooting Nosler 160 gr Accubonds with 59.0 gr 4831, WLRP, Winchster brass, seated 0.005" off the lands. FL sized once, Neck sized twice. This was a quick load that I threw together to go and test the rifle and it seemed to be shooting good so I have not done any further development on this.

I have shot my other rifles out to 550 yards, but neither of these yet. I just need to find time to get the ol' gong out and shoot somewhere.

As for the bullet pulling I pulled a few of the 6mm bullets and they did have some minute scratches on them. I have been reading up on fixing this problem, but to date the people I have asked are not concerned at all about an issue like this as I am. HoytemanPA I may have to try some of your suggestions to try an resolve this problem. I feel I am shooting ok with the two above mentioned rifles, but I feel they should be shooting better. I'll have to look at my dies (RCBS and Redding) and look at the expander balls to see how smooth they are, I am also playing with the idea of lightly polishing the inside of the case neck to achieve good nech tension. I don't turn my brass yet, but maybe some day.
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My focus has been low ES, and have settled in settings that provide this.
I neck size seperate from body sizing to produce .001" tension, one cal from the mouths.

This is enough tension that I can't change it by hand, but not so much that variance in tension is significant.
In contrast, if you use a lot of tension, then 10% variance of it is a lot.

Factors here; I don't seat into the lands, and I always shoot single shot.
I usually end up ~5thou off.
If I did seat into the lands, I would raise tension to 2or3thou. This, so I could exract rounds without pulling the bullets.

It will probably not show any measurable results on paper but it is a good thing to do.

This is what I have been meaning to do, but have not gotten around to it yet. Good video. I set up my drill press to do similar operations. Also my gunsmith the old BR shooter, with new brass, usually just adjusts his FL dies by the feel of the empty brass in a given chamber. I am not this experienced and I use the calipers, but he must be running his brass just near the max chamber dimensions. He said once you start to feel a very little resistance on the bolt closing, you are **** close to where you need to be. He also tests each piece of brass in the chamber to make sure it chambers. I still measure anyways!

Kind of getting off track, but I'll have to maybe try a batch of FL sized brass, and neck sized brass to see if there is any difference in my gun. I can see how doing the FL thing is going to keep your brass consistent over the life of the brass. I can also see how just FL sizing in a match quality chamber, with a die made the same time as the chamber is going to re-size the brass only a minute amount due to the fact that these chambers and dies are held to such tight tolerances. Where I am thinking that the neck sizing thing will help in my gun is that I don't have a custom FL die made with my barrel, and by FL sizing with a off the shelf die I will be working the brass much more than I need, and much more than the BR guys that FL size do. I know that the brass may eventually need to be FL sized but then it would require me to fire form again anyways. My gunsmith says that he has fired brass upwards of 40-50 times in his guns without FL sizing. My 7mm Mag was made by him, but the .243 was not, but should still have a good chamber.

I know some of this is like comparing apples to oranges, but there are many similarities among all these types of shooting styles.
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