Question about Neck Sizing Bushings

[Solidsnake87]

Hello all

I'm confused about the proper size selection of neck sizing bushings. Why do I need to purchase a series of these things? Is it because the casing shrinks dramatically with use?

I also do not know which is a good size to start with. .244-.252 is the range the redding recommends for use. Also, is there really that much of an advantage in the titanium nitride coated bushings? I could double the amount of bushings by just getting steel.

Thanks for your help.

-Clark

[ar15barrels]

You have to measure your brass to know what size bushing to get.
Then you will want a couple bushings around that size in order to account for differences in brass hardness.

Start with a loaded cartridge.
Measure the neck diameter.
Subtract 0.003" from that to allow for springback.
Purchase that busing size and then each bushing on either side of it.

Example:
Loaded case neck measures 0.250"
Subtract 3 thousandths gets you 0.247"
Buy the 0.246" and 0.248" bushings as well.
Harder brass has more springback so it requires a smaller bushing.
Softer brass has less springback so you can use a larger bushing.

If you run different types or different lots of brass, you will need different bushings.

[rksimple]

In addition to brass hardness/softness, brass thickness plays a part. You'll need a larger bushing for, say, Lapua brass than for winchester.

And on a related note, confirmed by some testing this weekend, keep the expander ball in unless you are going to turn necks.

[Fjold]

I measure my fired cartridges to see what size my chamber is first. Typically the neck of the fired cases will be about .002"-.003" smaller than your chamber neck because of the spring back of the brass.

Then I measure the loaded ammunition that I have to compare to it. If the difference in diameter of your loaded ammunition is smaller than the chamber neck diameter by more than .005"-.006", a bushing die will not do you much good.

If the chamber neck diameter is to much larger than your ammunition, your ammunition is laying in the bottom of the chamber and the bullet will be sitting below the bore line. It doesn't matter how concentric your ammunition is, the bullet will never be in direct alignment with your bore.

The whole purpose of bushing dies is to get finished ammunition that fits your chamber as closely as possible so that your loaded ammunition aligns the bullet as close to the center of the bore as possible.

The problem is if you have a typical factory cut chamber the neck diameter will be too large to ever get a close fit to the ammunition that you are loading.

If you look at Pac Nor's list of wildcat chambers for 22 caliber barrels you will see custom neck diameters listed. The listed .250" diameter is commonly called the "no-turn neck" so that if you are using match brass (Lapua, etc) that is very consistent, you should be able to use a .245" diameter bushing to make loaded finished ammunition of about .248" diameter without having to turn the necks down. This will give you about .003" of neck tension and .002" of space in the chamber for the bullet release.

PacNor available neck diameters:
222 Remington .239 neck (requires neck turning of brass)
222 Remington .245 neck (requires neck turning of brass)
222 Remington .246 neck (requires neck turning of brass)
222 Remington Magnum .246 neck (requires neck turning of brass)
22-250 Ackley .250 neck
22-250 Remington .250 neck
22-250 Remington .253 neck (common factory size)

[Ahhnother8]

Question about Neck Sizing Bushings
Hello all

I'm confused about the proper size selection of neck sizing bushings. Why do I need to purchase a series of these things? Is it because the casing shrinks dramatically with use?

I also do not know which is a good size to start with. .244-.252 is the range the redding recommends for use. Also, is there really that much of an advantage in the titanium nitride coated bushings? I could double the amount of bushings by just getting steel.

Thanks for your help.

-Clark

All the above posts are correct, but do you want to know the real secret?





























Call Sinclair International, tell them what brand of brass you are using, and what type of rifle (ie. bolt gun, gas gun), then do as they tell you. Problem solved. Once again, it depends on what you are trying to accomplish. And companies like that will go out of their way to provide the best advice and products possible. Use them to the fullest, they like it.

Lane

[robbor]

bushings

The range that redding states is huge. You do not need 3 bushings. I always buy a bushing .003 smaller than a loaded round then one size smaller. I use 22-250 bushing dies and when i polled about 6 other die owners they were almost all using a .247 bushing as I am. I have a 247 and 246. The Tin is supposed to be smoother and or require less to no lubrication. I only buy tin ones. I have also bought 3 bushings and then sent one back after i get brass and check sizes. If you want you can try wilson bushings, they are supposed to be tapered as i recall .0005 tighter on one side, (they are only made in steel).
Dont worry, just get one .003 smaller than a loaded round and you will be fine, to many other variables. I also use molly and they saw more neck tension can be better.