Interesting Observation - Bullet Runout vs Case

[Phil3]

I have been trying to minimize bullet runout on my 223 Remington cases, always perplexed that bullet runout can far exceed neck runout, even when the neck wall thickness is pretty consistent. Both Redding and Forster micrometer seaters seem to give the same kind of result. It just seemed to me that the bullet was going in crooked. The test cases were Winchester 1x fired, and FL resized. On a whim, I decided to test a brand new Lapua case. Its neck runout was about .001". I did not check neck wall thickness. I figured bullet runout would be considerable like it has always been with other cases, but I was wrong. Bullet runout was .001, the same as the neck. I am not sure why that is, and need to test more.

If anyone has an explanation why the bullet would seat more straight with Lapua brass vs prepped cheaper brass, would love to hear it. Bullets are Sierra 53 grain flat based.

Phil

 

[Erik Cortina]

I have been trying to minimize bullet runout on my 223 Remington cases, always perplexed that bullet runout can far exceed neck runout, even when the neck wall thickness is pretty consistent. Both Redding and Forster micrometer seaters seem to give the same kind of result. It just seemed to me that the bullet was going in crooked. The test cases were Winchester 1x fired, and FL resized. On a whim, I decided to test a brand new Lapua case. Its neck runout was about .001". I did not check neck wall thickness. I figured bullet runout would be considerable like it has always been with other cases, but I was wrong. Bullet runout was .001, the same as the neck. I am not sure why that is, and need to test more.

If anyone has an explanation why the bullet would seat more straight with Lapua brass vs prepped cheaper brass, would love to hear it. Bullets are Sierra 53 grain flat based.

Phil

It's easy, Lapua applies pixie dust on their brass before they are shipped out.

 

[Steve Blair]

It's easy, Lapua applies pixie dust on their brass before they are shipped out.

[br]
There is no hard evidence that pixie dust exists. It is likely a myth fabricated to explain phenomena that people do not understand. That said; nothing of the above should be construed as disparaging of pixies or their dust. And, if I have benefited in any way from said dust, I am deeply grateful for it.

 

[Pres100]

Erik is correct.
However, try seating a bullet and then raise press handle, turn the case in the shell holder 180 degrees an then reseat. Recheck runout. It may not eliminate it, but it may consistently reduce it

 

[mysticplayer]

Reduce neck tension to around 1 thou and problem will likely go away in the Rem brass

Jerry

 

[aj300mag]

It's easy, Lapua applies pixie dust on their brass before they are shipped out.

I've discovered that if you adjust the seater die to compensate for coriolis effect it enhances the benefit of the pixie dust...

 

[Shynloco]

I have been trying to minimize bullet runout on my 223 Remington cases, always perplexed that bullet runout can far exceed neck runout, even when the neck wall thickness is pretty consistent. Both Redding and Forster micrometer seaters seem to give the same kind of result. It just seemed to me that the bullet was going in crooked. The test cases were Winchester 1x fired, and FL resized. On a whim, I decided to test a brand new Lapua case. Its neck runout was about .001". I did not check neck wall thickness. I figured bullet runout would be considerable like it has always been with other cases, but I was wrong. Bullet runout was .001, the same as the neck. I am not sure why that is, and need to test more.

If anyone has an explanation why the bullet would seat more straight with Lapua brass vs prepped cheaper brass, would love to hear it. Bullets are Sierra 53 grain flat based.

Phil

You get what you pay for. Now you know why most serious shooters use Lapua brass and seat using Wilson Inline Dies.... It's known as "QUALITY" AKA PIXIE DUST!

Alex

 

[CatShooter]

I have been trying to minimize bullet runout on my 223 Remington cases, always perplexed that bullet runout can far exceed neck runout, even when the neck wall thickness is pretty consistent. Both Redding and Forster micrometer seaters seem to give the same kind of result. It just seemed to me that the bullet was going in crooked. The test cases were Winchester 1x fired, and FL resized. On a whim, I decided to test a brand new Lapua case. Its neck runout was about .001". I did not check neck wall thickness. I figured bullet runout would be considerable like it has always been with other cases, but I was wrong. Bullet runout was .001, the same as the neck. I am not sure why that is, and need to test more.

If anyone has an explanation why the bullet would seat more straight with Lapua brass vs prepped cheaper brass, would love to hear it. Bullets are Sierra 53 grain flat based.

Phil

There are "rules" when making tests - not my rules, it is just the way things are done if you want what you say to be credible.

One of the first and most basic rules is, you have to do each step the same to all samples - you cannot compare a once fired case with a new case, cuz there are chamber and die issues that can be introduced to the fired case that are not present in the new case.

 

[wapiti25]

I believe that annealed cases shoot more accurately. I do not have evidence but if you believe, it makes things easier. I also believe that when you do a 70% clean up neck turn on std commercial brass it helps even in std chambers.

 

[BoydAllen]

What you are seeing is the difference between neck runout (at the end of the neck) that is angular (neck at an angle to case and parallel runout (neck ID centerline parallel to CL of case body). With the angular runout the reading increases as you take readings farther from the end of the neck. The angular runout is a function of how the cases were sized.

 

[Phil3]

I have been trying to minimize bullet runout on my 223 Remington cases, always perplexed that bullet runout can far exceed neck runout, even when the neck wall thickness is pretty consistent. Both Redding and Forster micrometer seaters seem to give the same kind of result. It just seemed to me that the bullet was going in crooked. The test cases were Winchester 1x fired, and FL resized. On a whim, I decided to test a brand new Lapua case. Its neck runout was about .001". I did not check neck wall thickness. I figured bullet runout would be considerable like it has always been with other cases, but I was wrong. Bullet runout was .001, the same as the neck. I am not sure why that is, and need to test more.

If anyone has an explanation why the bullet would seat more straight with Lapua brass vs prepped cheaper brass, would love to hear it. Bullets are Sierra 53 grain flat based.

Phil

There are "rules" when making tests - not my rules, it is just the way things are done if you want what you say to be credible.

One of the first and most basic rules is, you have to do each step the same to all samples - you cannot compare a once fired case with a new case, cuz there are chamber and die issues that can be introduced to the fired case that are not present in the new case.

I am well aware of the "rules". On some other previous post, I had spoken of heavy bullet runout using NEW unfired Winchester cases, and the runout was worse than on 1x fired Winchesters. The NEW unfired Lapua was better than any Winchester case, new or unfired, even Winchesters with minimal neck wall thickness variation. I need to test more, but Winchester NEW vs Lapua NEW, the Lapua wins easily for bullet runout. But, will test more for a better sample size.

Phil

 

[Phil3]

What you are seeing is the difference between neck runout (at the end of the neck) that is angular (neck at an angle to case and parallel runout (neck ID centerline parallel to CL of case body). With the angular runout the reading increases as you take readings farther from the end of the neck. The angular runout is a function of how the cases were sized.

Understood. It would seem then that even a top notch bullet seater can not seat a bullet straight if the neck is crooked. ??? It also seems that the only way to straighten a crooked neck on new brass is to fire-form it to the chamber. After firing, and to maintain neck straightness, a neck die w/bushings, a FL bushing die, a Lee Collet die, or a custom honed FL die, are the only ways to achieve that. A regular FL die may cause the neck to cock with the expander coming through. Am I understanding this correctly?

On another note, my initial testing shows that the neck runout is less using a Forster FL die vs the Redding. Most certainly, the effort required on the press is less with the Forster vs the Redding, even though the Redding has a carbide expander button. Both size the neck down to the same size before the expander hits the neck. More testing needed.

Thank you.

Phil

 

[aj300mag]

You're reloading for an AR Phil, not a Dwight Scott built LV rifle in 6PPC. Your Krieger barrel won't know the difference between ammo with .001" TIR to .003" TIR.

Besides that, the search function is your friend.

 

[mikecr]

I think you're closing in on it Phil3.
Trust me, it has nothing to do with brass brand.
Likely it is the runout your sizing is producing.

 

[dboyles]

On another note, my initial testing shows that the neck runout is less using a Forster FL die vs the Redding.

Funny how things work versus how they're "supposed" to, right? I have also seen excellent results with a Forster FL sizing die, in my case using a polished expander ball.

 

[Phil3]

You're reloading for an AR Phil, not a Dwight Scott built LV rifle in 6PPC. Your Krieger barrel won't know the difference between ammo with .001" TIR to .003" TIR.

The AR may or may not care about some bullet runout (I am not convinced either way), but I am enjoying myself finding out. Further, I derive enjoyment out of making the finest ammo possible, regardless of whether the gun can appreciate it or not. I am not one to do something so it is "good enough".

Phil

 

[thefitter]

You're reloading for an AR Phil, not a Dwight Scott built LV rifle in 6PPC. Your Krieger barrel won't know the difference between ammo with .001" TIR to .003" TIR.

The AR may or may not care about some bullet runout (I am not convinced either way), but I am enjoying myself finding out. Further, I derive enjoyment out of making the finest ammo possible, regardless of whether the gun can appreciate it or not. I am not one to do something so it is "good enough".

Phil

Then you are in the right place! This is the home of some of the most anal retentive OCD mofos on the planet.

 

[lpreddick]

so many times i would measure "no" runout of case neck, seat bullet turning case when bullet half seated, then measure r/o of bullet... .002-.003! is the bullet going in crooked? my observations...a flat based bullet has the pressure ring usu measuring .0005 greater diameter than bearing surface. this ring is the main "stretching" component of the bullet. most, if not all, brass necks get a little thicker as it reaches the shoulder. i can feel the tightening as the ring goes deeper into thicker neck and you can see the slight buldge the ring makes in the neck. in short necks i wonder if the ring is like a pivot point for the bullet allowing it to ever so slightly cant until it's bearing surface encounters the lip of the neck. i have found a correction of .003 bullet runout to .001 if seated .020 into lands. measure, chamber, and remeasure. i have even corrected and over corrected this runout by pressing the bullet against a soft surface. there is a runout correction device that works on this principle. i can't accurately measure neck thickness but have noted the difference when inside neck reaming. the reamer will enter the neck 1-2 mm before engaging brass and as i go down the neck the resistance increases. this latter experiment is to see if reaming a neck that was sized with a bushing will produce a neck of uniform thickness and allow bullet seating with "no" runout. no conclusion yet but initial impression is that the resistance to bullet seating is uniform.

 

[savageshooter86]

Interesting thread. I was informed that runout is not as important as other parts of the reloading process. This person(who knows how to shoot and wind on national levels) purposely used loaded rounds with up to 007 runout and ones with near perfect runout. Shot them both under same conditions at 1000 yards. And what do you think he find out?..................... He could not tell the difference on paper. So to me this tells me it is a waste of time to pull hair out over 002 runout, or heck for some people 001 runout lol

Most people are not capable of shooting THAT consistent or have good enough technique to see a difference on paper by doing some of the "extreme" case prep and measuring

 

[Barlow]

Interesting thread. I was informed that runout is not as important as other parts of the reloading process. This person(who knows how to shoot and wind on national levels) purposely used loaded rounds with up to 007 runout and ones with near perfect runout. Shot them both under same conditions at 1000 yards. And what do you think he find out?..................... He could not tell the difference on paper. So to me this tells me it is a waste of time to pull hair out over 002 runout, or heck for some people 001 runout lol

Most people are not capable of shooting THAT consistent or have good enough technique to see a difference on paper by doing some of the "extreme" case prep and measuring

I always wondered how straight is straight enough. Does one or two or 5 thousands make much difference after the abuse a bullet takes while going down a barrel. I was shooting against a guy who was shooting a worn out 6BR a couple years ago, the throat was so worn he had the bullets seated out so far they were just barely in the neck. Not straight at all. He put 15 shots in the 10 ring at 300 twice and won the 300 no problem. I'm holding all my match loads at .001 or less, but Im not sure why. Barlow