Bullet run out

[SPAK]

Hey guys,

I've been trying to figure out where my bullet run out is coming from. I tested my fully prepped necks and most of them I can get between .001 and .0015" TIR on the necks. A few of them will read out to .002". More than that I'll set those pieces of brass aside.

I'm using a redding comp seater, and after seating my bullet runout varies from .001 to as much as .004" TIR.

The ones that were .003 to .004" I checked the concentricity of the necks (loaded round) and some of the necks were read .0015 while the overall run out of the bullet is .004"

Is this an acceptable level of runout for accuracy??
could some of the bullets themselves not be concentric?
Is there a way to sort for bullet concentricity before loading??
How much does this level of run out affect accuracy??

Thanks for the help, any input would be great.
case prep as follows:

lapua brass, skim neck turned

hornady 208 amax

rcbs JR3 single stage press

redding shellholder held in place with rubber o ring

redding body die

Trim and chamfer on wilson trimmer and with vld tool

clean ID of necks with nylon brush after tumble

lee collet neck die

redding comp seater, seat then rotate case 1/2 turn, then complete seating

 

[ChrisGarrett]

Re: Bullet run out

I have a Bersin concentricity gage/fixer for 7 RemMag and my personal standard is a TIR of 1.6/1000ths, so +/- .8/1000ths, which is easy to measure with a dial gage that has a resolution of 4/10,000ths.

Anything above this gets nudged back into alignment.

I measured rounds made with standard dies and TIR was anywhere from < 2/1000ths up to 11/1000ths, with most between 2 and 5. Rounds made with my Redding bushing neck dies and Comp seater were between nil and 3/1000ths.

From my research, runout seems to be caused mostly by unevenly made brass casings, which upon firing, give the case a banana shape to it, in essence bending the necks.

I plan on getting the bodies for 223/308 and perhaps 22-250 and 338LM. It's a great tool.

Chris

 

[Victor N TN]

Re: Bullet run out

Use a stiffer brush with 4/0 steel wool pushed into the bristles. I prefer bronze bore brush for the job. They will wear out too. Replace it when the fit gets too loose. Carbon fouling is a big culprit in runout when spinning.

I keep .004" for most things. .002" or less for match loads.

 

[SPAK]

Re: Bullet run out

I'll try the bronze brush. I've used them before, but like you said they wore out pretty fast...how do you put the steel wool on there? are you polishing the inside of the neck or just running it in and out to clean it?

 

[427Cobra]

Re: Bullet run out

I wrap the 0000 steel wool around the brush, and use a drill to spin it, I do it this way because it's faster, not trying to mirror polish the necks, just cleaning them.

 

[Furtaker_.223]

Re: Bullet run out

I bought a K&M neck turner to turn and tru up all my brass. The carbide guide has a dougnut cutter to trim any thickness inside the neck. Then bought the redding comp. neck sizing die. Really helped to get runout down to .001-.002

 

[Victor N TN]

Re: Bullet run out

I press the steel wool into the bristles with a gloved hand. I mount the brush in a RCBS "screw driver" handle. I twist pushing in and twist pulling out.

 

[SPAK]

Re: Bullet run out

I think I'll give that a go, when I clean with my nylon brush the inside of the necks are still black. They look clean, but perhaps I'm not getting them clean enough.

I'll clean out my seating die too and see if that helps some.

I'm on my 4th loading now, I think I'll need to anneal soon in the next two firings. That might change things as well.

 

[Rafael]

Re: Bullet run out

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Frogman77</div><div class="ubbcode-body">I'll try the bronze brush. I've used them before, but like you said they wore out pretty fast...how do you put the steel wool on there? are you polishing the inside of the neck or just running it in and out to clean it? </div></div>

I found that bronze bore brushes work great when I just push them in, twist, and pull out......by hand.
I have not found the need for spinning them with a power tool.

When they become too worn for bore cleaning they become my neck cleaning brushes.

This minor neck cleaning greatly reduced seated runout for me.

 

[SPAK]

Re: Bullet run out

Do you think the bronze brushes do a better job than the black nylon ones??

 

[Victor N TN]

Re: Bullet run out

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Frogman77</div><div class="ubbcode-body">Do you think the bronze brushes do a better job than the black nylon ones?? </div></div>

Without a doubt...!

You should not see any black on the cleaned case necks.

 

[SPAK]

Re: Bullet run out

Got it, I'm glad I asked, I stopped using the bronze brushes because I kept wearing them out cleaning my necks and the nylon seemed to be stiffer, but this is reason enough to go back. I'll try the steel wool too. Thanks for all the input guys!

 

[Rafael]

Re: Bullet run out

Victor knows what he is talking about......though I do not clean mine as well as he does. But then....I will never beat him in a BR match.

My accuracy requirements are pretty slack.

I find that just knocking off the loose fouling is good enough to achieve very low runout figures.....I leave the patina in the necks.

 

[Chanonry]

Re: Bullet run out

As you can see on another post I had a similar but more extreme problem. For what its worth:

I emailed Patrick Ryan at Redding and his suggestions included annealing the necks and ensuring I had a decent chamfer on the inside. Hardness wasn't this issue as the brass was once fired but putting a 'good' chamfer on the neck made a huge difference to seating induced runout. Runout is now <=1 thou from runouts of upto 9 thou

I have only ever had good advice and service from Pat

Andy

 

[SPAK]

Re: Bullet run out

I checked my chamfers using my wilson vld chamfer tool (hand crank lathe style) and some of the necks have an even chamfer all the way around and some have a small portion of the neck where it seems like there wasn't enough chamfer.

I thought about applying more pressure while turning the crank handle but I didn't want to cut away too much brass making that area too thin.

I chamfer after I trim using the wilson trimmer.

Any thoughts to remedy this? Is it possible I'm not trimming my brass enough to square the case mouths and thus not being able to chamfer all the way around?

Actually now that I'm thinking about it, It's probably my skim neck turning. I'm only turning my necks down to .0145" Some of the necks measure down to about .014" and the thinnest are down to .0135". The majority of the cases are between .0145" and .015" neck thickness.

I'm wondering if that's causing the variation in the neck chamfer...

 

[Victor N TN]

Re: Bullet run out

With the long slope of the VLD tool it will look like more than it really is. But yes a couple of thousandths will make it look like thin spots.

 

[SPAK]

Re: Bullet run out

So should I chamfer to make the cut even all around the case mouth or leave it as is. I'm not sure which is more important at this point...

 

[Victor N TN]

Re: Bullet run out

You're trying to keep the sharp edge of the brass from "shaving" the copper of the jacket when the bullet is seated. As long as the sharp edge is broken you should be fine. I do try to chamfer them all pretty much the same myself.

 

[SPAK]

Re: Bullet run out

Thanks victor, I appreciate your input.

 

[SPAK]

Re: Bullet run out

here's a small update. The steel wool definitely cleans the necks better!! I haven't loaded up my rounds yet but I'll report on the concentricity after the new neck cleaning...

however, I did find out that if I rotate my case in the wilson trimmer 180 degrees while I'm chamfering, I get an even cut all the way around the case mouth....I'll start doing it this way from now on.. but it does make me wonder if my trimer is really trimming square all the way around???

 

[SPAK]

Re: Bullet run out

ok, seated some bullets tonight. To start, 5 0ut of 22 cases measured .002" TIR on the necks and the rest were .0005-.001" TIR.

After seating, TIR on the loaded rounds varied anywhere from .0025-.007"

I even cleaned out my comp seater before seating to make sure that wasn't a variable.

Necks were annealed, cleaned out with steel wool wrapped on a brush, trimmed and chamferred with the wilson trimmer.

At some point I even loosened the locking ring on my die and let the die "float" to see if that made a difference but it didn't.

My results are worse than they were before.

just out of morbid curiosity I took a case that measured .001" on the case neck and seated a bullet using my lee seater die. TIR on the loaded round was .0015" I know it's only one case but even still that one result was better than all my results on the redding die.

don't get me wrong, the quality of the lee is no where even close to the redding, besides the fact I don't like the lee die.

Now I'm stumped...guess I'll call redding and pick their brain. I'm hoping it's just a stupid step in my procedure that I"m overlooking....

 

[Rafael]

Re: Bullet run out

Try this little experiment:
Seat the bullet a bit at a time, maybe 1/3 or 1/4 per pull of the press arm. After each pull, rotate the cartridge in the shellholder by the same increment.....1/3 for 1/3 or 1/4 for 1/4.

This "can" help with seating alignment but may also demonstrate a problem with alignment of the press/shellholder/seating-die.

Also....what are you using an o-ring for? Can you explain how it is used here? I have never felt the need for anything but the rams clip to hold the shellholder.

 

[Rafael]

Re: Bullet run out

Why did you turn the necks?
Also....it looks like you are using a Forster turner....is this the type that is used in the Forster lathe-type trimmer?

I am not real crazy about their turner setup.
Turning necks on that type of tool gives me little expectation of a straight or uniform neck since it indexes on the case-head instead of the neck..........how can you be sure the case-head is true to the inside of the neck?

I had one and either lost it, sold it, or gave it away.....on purpose.

 

[Victor N TN]

Re: Bullet run out

RAF

Doing the indexing thing was an old secret among high power shooter in the 1970s. I've done a LOT just like that.

I don't use O rings either. But I won't go into that.

 

[Short Round]

Re: Bullet run out

I was just getting back to my old .22-250 and couldn't figure out why my runout was through the roof.

At least mine was stupid, My seater lock nut was loose causing the seating stem to wiggle. I loaded up another batch and runout was near 1 instead of 8.

 

[Rafael]

Re: Bullet run out

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Victor N TN</div><div class="ubbcode-body">RAF

Doing the indexing thing was an old secret among high power shooter in the 1970s. I've done a LOT just like that.

I don't use O rings either. But I won't go into that. </div></div>

Yes, sir! I knew that. There are alot of little tricks like that which were left to us by our predecessors.
I never heard of the o-ring thing. Am curious though.

You know more about neck turning than I do....what do you think of tools that hold the case by the head and turn based on that fixture point?

 

[Victor N TN]

Re: Bullet run out

I have a Forester tool I mounted on a small block of wood. I would tighten the block up in a vise and not beat my knuckles bloody. BUT... Everything actually spaces off of the holding collet. Tightening it differently from case to case will make it turn differently. My tool uses a mandrel inside the neck to hold it. But it really wasn't that steady and repeatable. I'll try to get out in the shop this coming week and I'll try to get some decent photos I can post for you.

I bought the Forester tool in the mid 1970s I think. That lead to a home made turning tool I made after work one day. That lead to 2 different Sinclair tools when I started shooting benchrest. But my prize tool for turning case necks is the Neilson "Pumpkin" turning tool and inspection instrument. It's easily adjustable and REPEATABLE. You can adjust it to make 2 cuts in just a few minutes. If you mark the stops you can reset it in less than a minute. On the camming adjust side I put a piece of masking tape. with marks on settings. It litterally takes less than a minute to reset to a previous cutting adjustment.

 

[Rafael]

Re: Bullet run out

Yes, Victor.....I have a Forster tool like the one you have.

I would argue with you that unless the neck is true to the case-head, the turner will not be running into the the neck "true to the neck". The collet does not float, it centers in a cone at the fixture-end and if the perimeter of the case-head is not perfectly coaxial to the neck then the tool will not cut true.

Most peole are only removing a very small amount when they are doing a partial cleanup, but unless they are absolutely sure they are not working with even a slight banana-curve of the brass or a slightly distorted neck(from sizing or expanding) they may be doing more harm than good.

This is why I would prefer a turner like your pumpkin or the Sinclair NT3000 that I have....but have not used in some time since I do not have a tight-necked chamber and have found no appreciable improvement in lightly turned Lapua brass in my .308.
My loaded runout figures are very low for my shooting needs......less than .003" on the worst of them, less than .001" on the majority.

 

[Victor N TN]

Re: Bullet run out

On the Forester I have, if you tighten the handle on the back differently it changes the way the case is held. The tighter you make it the more difference in the way the case spins in it.

We may have different tools or maybe just set up differently.

 

[Rafael]

Re: Bullet run out

That may be.
Mine always centers the case head perimeter to the forcing cone on the body of the tool.

If yours spins the case, we certainly have different tools.
On mine the case is held stationary and the cutting tool spins.

 

[Victor N TN]

Re: Bullet run out

I'll try to get some photos for you tomorrow. We just got home from taking the grandkids home.

 

[Rafael]

Re: Bullet run out

No big deal, Victor. It's just a friendly discussion.....
...and your grandkids are certainly way more important.

Happy Fathers Day to you!

 

[SPAK]

Re: Bullet run out

I am using a forster neck turner but it's the kind that centers the neck on a center mandrel, and turn by hand.

I used the O ring on the shell holder at the suggestion of someone else with the thought that it would help with any mis alignment of the ram and die.

What are your thoughts on the lee collet die?? I'm thinking about trying a redding comp bushing neck die. I'm going to try another seater and shellholder and see what I come up with...I had a stuck case recently and I ripped the rim off with the shell holder. I doubt that it had any affect on the shell holder, but I guess I'm ruling out all the possiblities.

in the mean time I called redding and they said to send my seater back to them to take a look at.

I'm still willing to bet I'm missing something in my prep but, I just don't know..I do thank everyone for their inputs though..

 

[Rafael]

Re: Bullet run out

If your Forster tuner is like mine, the case is held still while the tool and mandrel revolved around/within the neck. Yes, the case neck is centered on the mandrel but the neck may not be straight.....and you could actually cut the neck in such a way that you are actually creating a neck of irregular thickness.

Other neck turners do not rely on the case being held in a fixture and the mandrel follows the inside of the neck to create a uniform thickness.

I doubt the o-ring will hurt anything, just never heard of it before.

I used the Collet die a long time ago and it can make some good ammo. I have moved on since then. I switched to Redding bushing dies so I could control neck tension and relieve myself of the need to keep the Collet die lubed. You cannot just switch components with the collet to achieve different tension....you can alter the mandrel.....but you cannot go back once you do this.....without buying a new mandrel.

 

[SPAK]

Re: Bullet run out

Yes, with my forster turner the case is held by my hand or chucked in a drill rather and I spin it while the mandrel is in the neck. I see your point though about the case neck not being straight. How would you remedy this? Can you give me an example of a neck turner that doesn't use a mandrel inside the neck that I could look at?


I use an expander mandrel from sinclairs first before neck turning. I usually measure after neck turning to check case neck and the thickness as far as where I measure goes is pretty consistent.

Is there a way to straighten the neck prior to neck turning? I suppose sizing the body and neck with a bushing die, then expanding the neck with the mandrel prior to turning??

 

[Rafael]

Re: Bullet run out

We may be talking about two different things here.

On my Forster trimmer/turner the case is held tight in a fixture that mounts on a frame that also holds the mandrel/cutter/crank handle. It is this arrangement that, I believe, is inferior to other turners.

Here is a link:
http://www.forsterproducts.com/catalog.asp?prodid=623128

If your tool does not hold the case on a frame that the mandrel/cutter shares....then you will not have the issue I am talking about here.

Many handheld trimmers have a tool that contains the cutter and mandrel that is held in one hand and the case is rotated independently of the cutter and mandrel....this should allow the mandrel and cutter to follw the neck properly.

Here is an example:
http://www.6mmbr.com/catalog/item/1433308/892387.htm

 

[SPAK]

Re: Bullet run out

Hey Rafael,

My neck turner is not the one in the forster link. Mine is simply hand held similar to the sinclair or the k&m.

I think that's where the confusion was

 

[ljmontano]

Re: Bullet run out

I have a Hornady 50 cal press and was using it to reload 338LM and i was having problems with run out and was using Forster dies, so I then got the Large jaws for my Forster coax press and my run out was cut down. I would reload 20 rounds and have 2-3 with over .0004 run out. I also use a Hornady concentricity gauge which allows you to correct the run out by applying presure to the high side of the bullet. I took several rounds of 260 which I corrected using the Hornady concentricity gauge and was able shoot 1/2 or better. For a 100 bucks I would go with the Hornady concentricity gauge and save some time and money

 

[SPAK]

Re: Bullet run out

I'm thinking about biting the bullet so to speak and buying a coax press. I have suspicions that maybe my old rcbs jr3 press just might not be cutting it.

 

[SPAK]

Re: Bullet run out

Another small update. Redding sent back my die and replaced the seat stem. I also started using a redding comp neck bushing die. My concentricity oy sized necks is at the worst .001". However, my comp seater is still scratching my bullets on one side near the case mouth and my run out is still any where from .0015 to .007" tir with most being around .004". I have a Forster coax on order and a k&m chamfer on order as well. My Wilson chmfer tool is still cutting uneven on all my brass. Cleaning the necks with steel wool definitely made for more uniform seating pressure but my runout issues still remain.

 

[astro3006]

Re: Bullet run out

I see Redding replace the seating stem. That's where I found my runout was coming from. I was reloading the .284 180 vld Bergers and nose of bullet was bottoming out on seating stem. I drilled seating stem deeper and my runout went away.

 

[SPAK]

Re: Bullet run out

I think I might have figured something out, although it's still problematic.

I took a known case to have low runout, seated a bullet 5 times and consistently got a seated round TIR of .001 or less.

So I think my sizing and seating process is sound.

then I annealed the case to see what would happen.

after annealing, my sized neck TIR still remained .001"

but after seating my TIR on the loaded round measured .0025-.003"

I'm using 650 deg F tempil stick about 1/4" below the shoulder and a propane torch. Rotating the case in a drill until I see the tempil stik just change.

Why would annealing cause increased runout??? Could it be because I annealed when it wasn't necessary? Would that change the characteristics of the brass that much??

Any Thoughts??