Redding bushing die setup

I am probably not understanding this correctly and that's why I'm having trouble figuring it out. But from my understanding I have to purchase a bushing to use inside of my type s neck sizing die. The way to determine what size bushing requires measuring the od of a neck after seating a bullet, but without sizing first how can I seat a bullet to measure it?

Measure a loaded factory load, preferably one of the same brand of brass you are going to reload. From that total o.d. subtract .002"= bushing size

If you have a way to accurately measure your brass neck thickness you can figure it out.
Brass neck x2 + bullet dia. -.003 will get you started for a bushing

Example: I have a box of Winchester 300 wsm, I measure a round out of the box it is .336". Subtract .002 from that and your bushing is a .334". If you want less neck tension make it a .335" or .333" for more neck tension

Typically new brass will be grossly undersized and you can seat a bullet in the new brass and take a measurement. I run .002 "neck tension" but .003 would work. Some guys try different ones but I have never had any problem getting well under .5 moa with .002 so I do not see a need to tinker with it.

@birdiemc

Thought you might like to see this one..

@birdiemc

May as well check this one out, too...

If you have new brass just seat one..measure. New brass shouldn't need to be sized to do this.

bob4 said:

If you have new brass just seat one..measure. New brass shouldn't need to be sized to do this.

Click to expand...

I've done this ^^^^^^^^ many times. Works well.

In the end you will probably buy other bushings unless you consistently use the same brass. If you neck-turn to clean up the brass necks you will need a smaller bushing then you started with. If you grab some brass from another source it could easily be a bit thicker/thinner in the neck wall and you'll need to change the bushing.

I've got a lot of spare bushings at this point.

Varmint Hunter said:

I've got a lot of spare bushings at this point.

Click to expand...

grab bag in my caliber .

The bushing size and using the expander also depends on if you are neck turning your brass.
If you Google Redding bushing FAQ there is much more information like the neck thickness variations below.

Tech Line & Tips (FAQs)
Bushing Selection
https://www.redding-reloading.com/tech-line-a-tips-faqs/140-bushing-selection

"If the neck wall thickness varies more than 0.002", it may be necessary to use a bushing a couple of thousandths smaller than your calculations indicate, and then use a size button in the die to determine the final inside neck diameter."

NOTE, in the same Redding bushing FAQ it also tells you if you reduce the neck diameter .004 or more you can induce neck runout. Meaning how much the neck diameter is reduced from its fired diameter. And if the necks are not turned the runout will be even more due to the uneven neck thickness. Bushing dies work best with tight neck chambers and neck turned brass. And this is why the Lee collet die is so popular, because you can reduce the neck diameter more with very little neck runout. Or just use a Forster full length die with its high mounted floating expander.

So with the equipment and tools I have on hand here's what I'm thinking, check the case neck ID of once fired brass with pin gage, then measure OD with calipers, should get me to wall thickness. Then do the math and order the bushing. Does that sound reasonable? Or will I run into problems using this method?

What brass are you using?

Nosler. Bought 2 boxes of factory loaded stuff to play with/start barrel break in, so I could have some decent brass to start out with.
Lots of problems there, but that was a whole different thread. Bergara b-14 hunter, 6.5 creedmoor.
Had to fire the nosler stuff in a different rifle, so it's not even formed to my chamber. Not how I had intended things to go, but adapt and overcome right?