Query: Brass concentricity?

[ELR LVR]

Assuming you have a decent quality FL sizing die, what do you do about brass runout if you encounter that?
Lets assume you don't have the funds to go out and buy a premium FL sizing die, you just have to try and make what you got work.

this has been covered before but...
... there is enough slop in the ram / to die threads / to shellholder to press/ to rim to shellholder
to align itself if you push the brass up first while its loose
then tighten down the lock ring
---
I have never seen and dont even know how my press could push the brass so sideways it would throw it out of concentricity.
it takes a lot of force to simply push a seated bullet sideways to correct concentricity by using v-blocks and a press (which I dont do, but just as an example)
---
unless you mean neck / bullet concentricity

 

[Thor357]

Your assuming run out is from a bad die. I would think they are made to about +/- 0.002".

When the bullet reaches the beginning of the rifling the chamber PSI is about 8000 PSI. This should make the case conform to the chamber. The forcing cone that the bullet passes thru before it hits the rifling land is only about 1 thou bigger than bullet diameter. The accuracy you need depends on what you’re going to use the rifle for. It takes a lot more than measuring a few things to make a rifle competitive. I only have to shoot about five shots to decide if my barrel has a chance at shooting under ½”. You have to decide what the rifle is capable of and l live with it. Reloading ammo only helps to a certain degree. You cann't make a factory rifle shoot like a competitive rifle by reloading ammo.

I was just trying to eliminate the die as being the source of the run out.

I'm not anywhere near your level of expertise and I may not live long enough to get there.

Yeah my rifle is "mostly" factory but I've done a few things that I think, maybe, make it slightly better than factory, maybe not by much though.
I don't have the money to buy a full custom rifle, have someone make one for me or even buy a nice used one let alone the skills or knowledge to make my own. And my goals are not to compete, just to shoot the best I can with what I got.

I started reloading about 5 years ago with the initial intention of saving money. Quickly learned that wasn't going to happen, I just ended up shooting more!
It became, some time ago, a hobby I enjoy. And shooting is the reward.

That's pretty much it. I'm just really looking to make what I got do the best it can and that includes my skills, or lack thereof shooting my rifle. That's all.

 

[Thor357]

Curious - why are you just now looking at run-out?

I dunno, probably because I watched some stupid YT video, heard about it, read about. I don't even remember why anymore!
I'm not the sharpest tool in the shed!

 

[Thor357]

this has been covered before but...
... there is enough slop in the ram / to die threads / to shellholder to press/ to rim to shellholder
to align itself if you push the brass up first while its loose
then tighten down the lock ring
---
I have never seen and dont even know how my press could push the brass so sideways it would throw it out of concentricity.
it takes a lot of force to simply push a seated bullet sideways to correct concentricity by using v-blocks and a press (which I dont do, but just as an example)
---
unless you mean neck / bullet concentricity

Yeah, in my last job we called that tolerance stacking.
Yeah I meant neck/bullet concentricity. I, just for grins and giggles, decided to see if the cases were concentric and they weren't so I thought maybe that's why my bullets wobble tad bit. After all the input folks have provided, it seems I might be fussing about something I don't need to be. My bullets for the most part wobble very little, from 0.000-0.004 at the most for only a few out of 50 or so. I don't know, that could be horrible for all I know. Plus the gage is the Hornady one and apparently I need to relegate it to being a nice new shiny paper weight!

 

[Thor357]

Since you have an aftermarket barrel, it's *probably* fine, but best to check and verify.

How do I "check and verify" a barrel?

 

[JEFFPPC]

Good ponit by Mulligan....keep your shell holder clean.

 

[DShortt]

How do I "check and verify" a barrel?

Oooooh, boy. Well this will open a can 'o worms.

If it were new or nearly new, I'd check the diameter at both ends using a lead slug. And slug the entire length checking for constrictions or loose spots. I'd also use a borescope to see how even the neck/throat/leade areas look.

But. Given that you've stated that the barrel already has 3K rounds down it, that won't tell us much now.

If you've had accurate groups with other powder/bullet combinations, why are you still experimenting?

Do you use wind flags?

Lots of possibilities that have nothing to do with run-out of your loaded rounds.

If you just want to load 50 rounds of this and 50 rounds of that and go shoot, that's fine. But that's not going to help with anything but trigger time.

What exactly are you trying to accomplish?

 

[ELR LVR]

Yeah, in my last job we called that tolerance stacking.
Yeah I meant neck/bullet concentricity. I, just for grins and giggles, decided to see if the cases were concentric and they weren't so I thought maybe that's why my bullets wobble tad bit. After all the input folks have provided, it seems I might be fussing about something I don't need to be. My bullets for the most part wobble very little, from 0.000-0.004 at the most for only a few out of 50 or so. I don't know, that could be horrible for all I know. Plus the gage is the Hornady one and apparently I need to relegate it to being a nice new shiny paper weight!

Ok, yeah Tolerance stacking or error stacking
thats correct
---
And Im glad you meant Bullet Concentricity.
First the case needs to be fireformed to the chamber well
neck turning also help to ensure one side isnt thicker than the other
Neck tension is a big role player here
Think: the more neck tension, the more the shoulder collapses and springs back
So I go for light neck tension so the bullet slips in with less effort and doesnt deform the shoulder any
---
With this I usually get .001" or less concentricity
with new Lapua brass, the neck tension is so high, I get like .010" out of concentricity
.003" or less is great

 

[Thor357]

So I go for light neck tension so the bullet slips in with less effort and doesnt deform the shoulder any

Yeah, I go for light neck tension too. It's around 0.3065 vs 0.308.

 

[Thor357]

With this I usually get .001" or less concentricity
with new Lapua brass, the neck tension is so high, I get like .010" out of concentricity
.003" or less is great

I don't have any new Lapua brass on hand. But I do have 50 that I've used maybe 5 or 6 times that have been prepped awhile back that are at about 0.003 or less neck tension.

 

[Thor357]

If you've had accurate groups with other powder/bullet combinations, why are you still experimenting?

I'm not a hunter or a competition shooter, just a guy that likes to shoot a lot and sometimes I try other stuff because someone recommend I try this or that.
I try to keep my experimenting to a minimum because I don't to end up with shelves of unused stuff.

Think of it like this. Some folks go out and buy a new every few years and other guys like me keep driving what they got until it starts nickel and dime-ing them to death AND then buys another car. That's me.

 

[Thor357]

Do you use wind flags?

Yes but I need to put up new ones. The current ones are wore out.

 

[Thor357]

What exactly are you trying to accomplish?

To make what I got shoot the best it can...repeatedly.
That includes all the gear I have to reload.
It may not be the best stuff there is but I'm pretty sure it's not junk either.

 

[DShortt]

To make what I got shoot the best it can...repeatedly.
That includes all the gear I have to reload.
It may not be the best stuff there is but I'm pretty sure it's not junk either.

OK, well if you want to test the effect of concentricity/run out on the target with your rifle, I would only do that with a known, proven load and not with something you're testing.

Otherwise, you're changing 2 or more things at once which I would avoid as I mentioned earlier.

 

[RB64]

Actually there is. The instruction sheet that comes with the gage says to find the lowest result and then use the screw fixture to "push" on the bullet to just past the highest point that was measured. It works...sorta!
I found that if there is more than .005 runout, it can be tricky to get it to less than .002 and I sometimes can't get it straight at all.
I've got a LE Wilson seating die that uses an arbor press coming in Monday. Hopefully it'll help...hopefully!

Me again , I found that moving the bullet on a Hornady set up actually made groups worse . Most benchers shooters once the set the bullet will never move it again . If they do for some reason , they become foulers . I also have experience with Redding S bushing dies . If you're moving the neck more than .006 you will likely experience concentricity problems . Even Redding suggest getting 2 bushings to take it down slowly . I use a custom honed die from Forster and get fantastic results . Just fill out the paper , send three fired cases with die ( I send cases fired at least 3 times ) Take a accurate measurement of a loaded neck with a proper device and have them hone it around .004 from where you want to be . any questions call them . I have $300 die sets sitting in my safe that I oil every year and thats all I do with them . The bullet concentricity starts with the case . Hang in there !

 

[Thor357]

OK, well if you want to test the effect of concentricity on the target with your rifle, I would only do that with a known, proven load and not with something you're testing.

Otherwise, you're changing 2 or more things at once which I would avoid as I mentioned earlier.

Yep, I agree, I need to slow down and do one thing at a time to find what works.
I may be confusing folks though.
When I make a batch of ammo (50), I make everything the same as best I can with what I got and what I've learned.

OK, well if you want to test the effect of concentricity/run out on the target with your rifle, I would only do that with a known, proven load and not with something you're testing.

Otherwise, you're changing 2 or more things at once which I would avoid as I mentioned earlier.

OK, well if you want to test the effect of concentricity/run out on the target with your rifle, I would only do that with a known, proven load and not with something you're testing.

Otherwise, you're changing 2 or more things at once which I would avoid as I mentioned earlier.

Here's a pic of my ammo box that I shot on the 3rd. I checked 10 or so for run-out (banana?) and every single one barely moved the needle!
I'm not sure what that means but has to be good, right?

I color coded them so I know what powder charge I used for each row as I'm making them.
I knocked over a box of completed ammo a few years back with no color code and I had to take them back home and re-do them. It was a PITA and I vowed to never let that happen again so I came up with this simple solution just in case.

 

[Thor357]

Even Redding suggest getting 2 bushings to take it down slowly

Yeah, I got 5 of the bushings. 2 below the required one and 2 above just in case.
As of lately, I'm seeing 0.002-0.0005 movement so the problem I had has gone away since I bought a better gage (Sinclair). My sizing die and seating dies seem to be doing a good job. I got an LE Wilson inline seater die the other day and it produces excellent results as well.

 

[DShortt]

Yep, I agree, I need to slow down and do one thing at a time to find what works.
I may be confusing folks though.
When I make a batch of ammo (50), I make everything the same as best I can with what I got and what I've learned.



Here's a pic of my ammo box that I shot on the 3rd. I checked 10 or so for run-out (banana?) and every single one barely moved the needle!
I'm not sure what that means but has to be good, right?

I color coded them so I know what powder charge I used for each row as I'm making them.
I knocked over a box of completed ammo a few years back with no color code and I had to take them back home and re-do them. It was a PITA and I vowed to never let that happen again so I came up with this simple solution just in case.

If you have next to -0- run-out on the fired cases, re-check after sizing. If still next to -0-, check a final time after loading. Still should be next to -0- run out.
If you DO find run-out, then you'll know what step it occurred in.

 

[Thor357]

If you have next to -0- run-out on the fired cases, re-check after sizing. If still next to -0-, check a final time after loading. Still should be next to -0- run out.
If you DO find run-out, then you'll know what step it occurred in.

You're one of the "good guy's" aren't ya!
I really appreciate you taking the time to work with me.
You've been very helpful.
So much info has been offered and I'm trying to keep everything sorted but man! It seems I have soooo much more to learn. Thanks again!!!

 

[ShaunBrady]

The way I approach concentricity is anything under 0.003" TIR is in the noise on a half moa gun.

With neck turned brass, it's easy to keep it all under 0.002". Anybody's fixed neck sizing die and a Lyman M die as an expander mandrel. Brass prep includes annealing, chamfering, lubing the inside of the neck with Imperial. I have a rack for a cheap big ultrasonic cleaner that I use to remove the lube after sizing. In the past, I kept a separate tumbler with clean walnut shells to remove the lube. In the winter, I'd heat the brass with a heat gun to melt the lube before dumping it in the tumbler.

The brass will never be straighter than it comes out of the chamber after firing. On a bulk basis, runout only increases through the loading process. The idea is to minimize that.

"Overworking" the brass is thrown around a lot and seldom defined. Let's open with 0.010" change in neck diameter from fired to the smallest point in the sizing process. If I'm in complete control of the process, I'll spec the reamer for 0.006" neck clearance. The brass is sized 0.004" undersized, then brought to 0.002" before seating the bullet. Sometimes I'll order a fixed neck sizing die to make that land right. Sometimes I'll start with an off the shelf die and work from there if it doesn't require too thin a neck to work.

If the brass isn't neck turned, 2X the difference in neck thickness is added to the sizing process induced runout. The reason the fired brass will still be concentric is that variation was pushed to the inside of the neck. If you use a bushing to size to seating neck tension w/o a mandrel, the brass will still look as concentric as the turned brass. Until you seat the bullet. I don't know where you guys are getting all that perfect Lapua brass because they sure the hell won't sell it to me.

After that, the best metric I can come up with to gauge potential runout is sizing effort. The more the brass is worked, the more the runout is likely to increase. Working the neck 0.010" is usually OK if the brass is annealed. If not, 0.006" - 0.008" is a better number after a few firings, depending on neck thickness. I'm not sure what the correction should be for expanding the necks dry? Pretty much ignore concentricity? Graphite is a half measure. If I'm necking down a case to wildcat it, I'll go in 0.006"-0.008" steps. 338 to 308 in one shot gives runouts over 0.010".

An interesting exercise is to set the bump on the sizer die and then measure the shoulder position with and without the expander ball, lubed and unlubed. An unlubed expander ball pulls the shoulder back up more than you'd expect.

On expander balls and mandrels, I've run into guys who were told to lose the expander ball or use a mandrel, but not in the same sentence. One dropped the expander ball in a fixed neck die but didn't replace it with a mandrel and was seating bullets with 0.006" neck tension. The other started using a mandrel but left the expander ball in the sizing die. Both reasonably intelligent and mechanically inclined people. Don't be those guys.

Straightening loaded ammo is the worst idea I've heard in a while. Take a medium sized pair of lineman's pliers and cut a bullet in half across the bearing area. Report back on how much support you now think the jacket is providing. It's not even a condom for the lead core. It's the lubricant on the condom. Pushing on the bullet, or neck with the bullet under it, is only going to produce a flat spot or bend it. You'll make a much larger accuracy problem than the 0.003" runout you started with.