Concentricity/Neck Turning/Culling Cases:

[Comancheria]

Folks,

I tried my best to research this question on the reloading page, but was unsuccessful in finding the answers to my specific question:

I have all the precision loading tools you could hope for. I will soon be reloading for .300 Win Mag and .300 RUM, using Berger Bullets.

I have a new inventory of 300 Remington cases in .300 RUM and 100 cases in the Winnie. I will soon be the proud owner of 300 rounds of Berger factory bullets--which, when shot, will be a source of what I suspect will be excellent cases for the future. I realize the Remington cases are not everyone's favorite.

My question is as follows: I have the Sinclair Case Sorting Tool and the Sinclair Concentricity Tool, each with its own dial indicator--as well as the Sinclair Case Turning Tool. It is my understanding (please correct me if I am wrong!) that I can use the Concentricity Tool to determine (1) Bullet runout on reloaded OR factory ammo, AND (2) neck concentricity with case, measured at the neck, either fired or re-sized). It is also my understanding that I can use the sorting tool to measure neck thickness for consistency.

So, OK--I am sitting down at my bench with say, 100 new cases in front of me. I measure them on both tools:

(1) At what point in non-concentricity of neck to body should I cull the case? Or should I resize the case no matter how out of whack it is, and remeasure?

(2) Same question with regard to inconsistency in neck thickness? Is there a recommended difference in thousandths at which one should give up on the case?

(3) I hear about "banana cases" and how they should be culled. I think the whole concept with which I am struggling here is this: How do you know when you have a non-salvageable case?

(4) With regards to neck turning, I realize that some people think is stupid EVER to turn and some who do it religiously. Question is: If you do turn case necks, after running an expander through the necks, how many thousandths out-of even

Thanks as always for your advice--sorry that it is such a one-way street!

Best regards,

Russ

 

[ar10ar15man]

simply the wrong choice in case maker to start with.
its gonna be some work.
my 300 win mag match brass was RWS
MY 338 is ADG
MOST ELSE IS LAPUA.
there is no rem nor winchester in match guns

 

[SidecarFlip]

simply the wrong choice in case maker to start with.
its gonna be some work.
my 300 win mag match brass was RWS
MY 338 is ADG
MOST ELSE IS LAPUA.
there is no rem nor winchester in match guns

+1 Junk cases equal junk loads.

 

[odoylerules]

I've gotten to the point where I start with who makes the brass when deciding on which caliber rifle to build. I'd rather make tiny little improvements to quality brass than working with junk. Lapua is my go to, ADG has got a good reputation going too.

 

[SidecarFlip]

Lapua or Nosler (300 WM) No punched primer hoes for me and no burrs either.

I have used PPU in 338 Lapua with good results but prefer Lapua brass overall.

 

[Alibiiv]

Hello Russ, I'm not a fan of Remington cases either, however if that is what you have that is what you work with. I have plenty of reloading components in the basement that I wished that I hadn't bought because I found out after the purchase that there were better choices I could have made. Plus if you are just starting out, learning on the most expensive components could me a waste of money. I recently bought some .270 Winchester brass that I wished I'd hadn't bought, however since I have it I don't mind when I mess something up while setting the neck turning tool up. I'm still learning, what you will find in the reloading process "when asking a question" that usually there will be a number of opinions, I suggest that you try the one/s that fit you best. For me that is part of the learning process when learning precision reloading. How long have you been reloading? What have you been reloading for, what cartridges? I'm not exactly certain about what you are asking for? No matter where I start out measuring, before I do anything I always resize the brass, new or old. Just because the brass is new, it doesn't make it right. When checking for concentricity of bullet run-out, I try to stay within .0005-001 thousandths; you will find some people feel that it doesn't matter. I don't have the neck thickness totally figured out as of yet, however from what I have read in the various posts, .0005 thousandths or less is a good place to be. I hope this helps answer your question.

 

[sedancowboy]

So let me get this straight in my mind. You have 300 Rem 300 Rum cases and 100 Rem 300 WM cases + 300 loaded cartridges from Berger? What cases do Berger use? Since they are part of the group I would assume they use Lapua if it is available. Lapua does not make 300 WM. If I understand correctly this is a nightmare in the making. What Berger loaded ammo do you have coming is it all for 300 RUM or 300 WM or some of both? You could have several brands of brass when it is all said and done. Pick one brand for each cartridge and stick with it.
Now to your question I would expand and then turn each case. I turn only until I have cleaned up about 80-90% of the case neck. Or in the case of too thick necks I turn to about .014-.015 that seems to be a good thickness for most bushing dies and chambers. next I would load a med load and shoot them to fire form them to your chamber. Now measure the runout on the neck and see where you are at. If your chamber is concentric you are golden. Now as you reload your fire formed case measure after each step and see if you can maintain the same runout as your fired case.
If not you have some work to do. I use a bushing die with no expander inside. If my necks are the same thickness them I don't need to expand before seating a bullet. How you seat the bullet can have a major impact on how concentric your ammo will be. I rotate the cartridge as I seat the bullet in steps. No less than two start the bullet and raise the handle and rotate the case 180 degrees and finish seating you can rotate and seat more times if you like.
Good luck the search engine is your friend and this subject has been discussed many many times.

 

[Comancheria]

Thanks for all your considered replies, Gentlemen. First a little bit of the back story: I have actually reloaded before—primarily during the 70s and 80s—creating pretty ordinary fodder for an AR-15 and some hunting rifles which I never shot beyond 200 yards. Everything worked. At the time, I was generally aware of more precise processes.

As I prepared for retirement, I stocked up on a really good and complete reloading setup.

Fast forward to the great Ammo and Component shortages attendant upon a certain previous political situation—Remington was about all I could get. (Also stocked up on RL22 and 25–together with all of its temperature sensitivity )

So yeah—I do understand what all of you are saying. Lapua would be nice, but they don't make cases for either of my two calibers. That's where I hope the Berger Win Mag 215 and 230 grain loaded Ammo I am stocking up on will come in—1: if the bullets work in my barrel, more's the better—and whether or not they do, I will have 300 presumably premium cases with which to work. (Norma? Nosler?—of course, Berger ain't talkin'!)

Meantime, my best (and expensive) hope is for Berger to grow their loaded product line to include .300 RUM. Wouldn't 230 grain OTMs be nice!

I did a little more research and here is what I am thinking as to my original question: Resize both new and fired brass—even though the new stuff is highly unlikely to even touch the sides of the dies. Then use the Concentricity Gauge to measure runout on the case necks—abandoning any cases over say, .001 of runout.

 

[Comancheria]

Sedan—the Berger Ammo is all .300 Win Mag. No .300 RUM Berger loaded Ammo available—at least yet. You are correct that Lapua does not make either case. I would guess it is all Norma.

If the Remington brass doesn't work well, even with culling, I may just buy a few hundred solids to use against the rusted-out 1950s Chevrolets loaded with freshly-emerged zombies as they speed toward the northern stockade of my house!

 

[entoptics]

I would disagree with the idea that the Remington brass is a lost cause. I've made plenty of loads that were better than the guns or shooters they were meant for, using scrounged brass of various kinds. That being said, if you have a serious gun and/or are a superb shooter, then maybe you will see a difference.

IMO, there is not much point worrying about concentricity of the brass until you've fired it once, let alone before even sizing it. Even new brass that is WAY out of spec (>0.005 runout or so), might be just peachy after you fire it.

If it were me, I'd weight sort the brass, select a few pieces with similar weight, and perform the following steps. Load those up, and do a direct comparison against the Berger factory ammo. If you get equivalent results, or better, then you know you can do fine with what you have.

1) Ream all the flash holes for "dangling chad" and uniformity.

2) Turn all the necks to the same thickness, with a tolerance of about ±0.0005. Unless the brass is excessively thick (>0.015"), leave as much as possible. If a piece of brass is so bad that you can't maintain a neck thickness of >0.0125" then it should be culled. As mentioned, you don't need to turn them down any more than necessary. When I'm done turning a new batch, VERY few, if any, of the necks will have been completely touched by the cutter. Just take off the high spots, so to speak. You may need to turn a few to figure out what the ideal setting is. Set it thick at first, turn a few, see how much is remaining, lower the cutter a smidge, rinse, and repeat till you find a happy medium.

3) Run through a bushing sizer. You may have to guess the right size bushing at first, or better yet, measure a fired piece of brass with uniform neck walls, then calculate the right bushing based on that.

4) Load up 20-30 of the above, and see if they give you consistent results compared to the Berger ammo. If so, do the whole batch, and enjoy. If not, toss the brass and buy a 6.5 Creedmoor, as I've read it's a 1 mile lightning bolt with cheap factory ammo...

 

[Comancheria]

Thanks, entoptics. The answers to your 2 threshold questions are as follows:

I have two serious rifles.

I am NOT anywhere near a superb marksman!

To hijack my own thread slightly, I saw a video by a very serious reloader and long-range shooter, in which he said that—unless you fire form, resize, and trim for length—weighing brass is essentially worthless.

I can definitely see that that might make the process more useful—but worthless?

 

[entoptics]

Thanks, entoptics. The answers to your 2 threshold questions are as follows:

I have two serious rifles.

I am NOT anywhere near a superb marksman!

To hijack my own thread slightly, I saw a video by a very serious reloader and long-range shooter, in which he said that—unless you fire form, resize, and trim for length—weighing brass is essentially worthless.

I can definitely see that that might make the process more useful—but worthless?

I'd say it's a matter of degree. The concept behind weighing the brass, is that if all exterior dimensions are the same, then weight is proportional to brass, and therefore interior dimension (i.e. volume).

In your case, I was suggesting the weight sorting as a "first approximation" of conformity. Indeed, if the neck thickness, body dimension, and/or OAL are dramatically different, then it's definitely gonna give you a large error in interior volume approximation. That being said, it's a good way to get a feel for how much variation there is in your brass.

In summary, I'd say add another step to my above recommendations. Length sort all the brass first. THEN weight sort from brass with an OAL of ± 0.001", THEN select a few dozen cases to try the rest of the steps.

 

[dok7mm]

Here is my suggestion......Sort your brass by weight, just an initial sort, into 3-100 rd. lots. Take the 100 + 20 extra from the middle weight group and store or sell the rest.

Fire form those 120 pieces, then size, trim only if necessary. Then you can refine the weights of your prepped brass into 2-50 rd boxes and use the 20 outliers for fouling rounds.

This is just one step, but those 120 cases will take you a long way, if you stay away from Max pressure.

 

[entoptics]

I'd add one more step to my recommendations...

Since you have the tools, I'd check concentricity on the Berger ammo, as well as the ammo you make to test. No harm in getting a baseline. Perhaps even sort by concentricity, and shoot groups with batches of increasing concentricity. If you get the same results with 0.001" runout as 0.004" runout, then you know it's not a factor for your rifles/skill level.