This seems impossible

[Tiny Tim]

Tagging in. Having a similar issue with my Redding 243 ai bushing die. Just haven't got around to checking things out. Bow opener in 2 days.

 

[DUSTY NOGGIN]

.While seating some 140 Bergers I noticed that seating pressure was high and that a ring was being imprinted on the bullet's ojive. Loaded rounds had a neck diameter of .292".

What am I missing here?

you need grafite in the necks and a 289 to 290 bushing...

ive seen redding bushings be off but only by .001

 

[Varmint Hunter]

I'm typically working with about .003" neck tension and have never used a lubricant in a neck. I would have expected the .288 bushing to have worked fine but for some reason it didn't. It certainly "appears" that the bushing is much smaller than the stamped size on it. I ordered a .290.

I really hope ADG produces some brass soon so I can start fresh.

 

[cdherman]

This:

Reloading Measuring Tools: Comparators, Calipers, & Micrometers

Browse 130+ Reloading Measuring Tools Products including Bullet Comparators, Calipers & Micrometers, & Concentricity Gauges from premium brands including Redding, Whidden Gunworks, Hornady, and more!

www.brownells.com

Or this:
https://www.amazon.com/dp/B07KCRKHF5/?tag=lrhmag19-20

You really need to know neck thickness before you play with bushing dies. The tools to measure are helpful in so many ways. I start by measureing a bunch of necks in multiple spots with each new lot of cartridges. Tells me whether I have a problem that will requite neck turning, and it tells me what bushing will give me the tension I desire.

 

[30BR]

What's the wall thickness of the brass? You might want to try some different sized mandrels for setting the ID after the neck bushing. KM has a kit you build by sku, Whidden has sets of mandrels by caliber...

 

[DUSTY NOGGIN]

id get a neck turner and turn down to the size bushings that you have ..

were all of the seatings hard of just an occasional???

as said ealier ,annealing wouldnt hurt

 

[DUSTY NOGGIN]

(.292-.2645)/2=.01375

measure all seated in all directions and see if they are all .292

if you did a skim pass turn operation on that brass and got em down to .0125 that 288 bushing would be perfect

 

[Bob Wright]

(.292-.2645)/2=.01375

measure all seated in all directions and see if they are all .292

if you did a skim pass turn operation on that brass and got em down to .0125 that 288 bushing would be perfect

Dusty is correct.
Since I had the dreaded donut issue, I bought the K&M turner and reamer. Once I got done, all the necks were .0125, no taper and no thick or thin areas. The bushing does all my sizing now for a .002 neck tension. Whatever variation in wall thickness, the bushing is going to round up the o.d. and force any irregularities to the i.d. When you seat the bullet, it's not a happy fit. Shaving bullets when seating or uncontrolled neck tension is going to be the norm. The copper jacket is at the mercy of harder brass.
Annealing is a big plus too.
Lots of loaders use a mandrel die to size the i.d. of the neck, turned or not. Turning just guarantees wall consistency and uniform neck tension, 360° around.

 

[243winxb]

When you size down too far in one step, a bushing will tend to size below it's marked diameter

its on Reddings website.
Redding has sizing down more then .008" in 1 step.

 

[Mikecr]

DocDoc is right at post#7
It's a matter of angles. Too much sizing in one step creates high sizing angles that roll brass further inward. Redding may have claimed 8thou, but it can be seen with any sizing greater than 5thou at a time.
Given this as an incalculable variance(as far as I know), what's stamped on bushings or what you find checking with pins is only a starting point. Trial & error will show you the truths.

So you'll need an intermediary bushing (2-step sizing), and/or stop oversizing, and you need to better measure what you have and what you're doing.
More important still is to learn as much as you can from this.