I have a redding competition necksizing die that I need to get bushings for. I read how I should take measurements of loaded bullets and subtract .001 or .002 from the reading and get THAT bushing for good sizing of the necks. Problem is I am getting too many readings. Im thinking that I will have to maybe get a bushing for the 155 nosler match bullets....a bushing for the 110 v-max bullets...and a bushing for the 168 nosler and sierras I am reloading. Does this sound right? The bullets that I reloaded and measured came from regular rcbs dies using a rockchucker press.

Hmmmm, no, it doesn't sound right.
You should measure the neck diameter of loaded rounds. Even with different bullets, the measurement shouldn't vary much, if any, as bullet diameter won't vary much at all.
What you might be running into is different neck thicknesses of your cases. If that's what the problem is, a light neck turning to get uniform neck thickness might be in order.
Try this: take an empty case, size it, and seat a bullet (no primer or powder). Measure the neck diameter, as per Redding instructions. Record that measurement. Now, pull the bullet, resize the case, and seat one of the other bullet styles. Repeat the measuring.
Do that for each bullet with the SAME case. See if your measurement varies (I kinda think it won't)

Hi Yooper

I don't have a competition die - I use a standard set of Redding - so I can only help you so much.

Thing is, I don't really understand what it is that you are trying to do. The overall length of the cartridge is what we are after. That in it'self is a bit misleading because to be precise, you are looking to measure from the head of the case - where the primer goes - to the point where the ogive (the curvature of the bullet it'self) touches the lands of the barrel. that's what we need to adjust.

What we want to achieve is that the bullet is about 0.002 - 0.005 of an inch 'off' the lands. this means that there is no time when the bullet is in free air. If it's not in the case then it's in the barrel. Some folks say that this leads to increased accuracy.

If you get a stoney point measuring device you can measure this exactly. Or, make up a round with no primer or powder and colour in the bullet with a marker pen. Then start to chamber the round, do it slowly and feel is the most important. The lands - the rifling of the barrel - will scratch the ink. If that happens then the OAL is too much. Put the round back in the press and increase the seating depth by a couple of 'thou. Try again.

If you've got a Precision die for say .308 then you won't need anything else. It will load every .30 cal bullet into a .308 case no matter what make or model.

Hope this helps.

D

Here is a bit of information that may be usefull. One thing to remember is that you will need to ream or turn your necks to a uniform thickness for best results and not use an expander button in your dies.


Leading benchrest die makers such as Neil Jones and L.E. Wilson solved the problem for precision reloaders decades ago by introducing dies fitted with interchangeable neck sizing and shoulder bump bushings -- dies that could be tailored exactly to the thickness of the brass in the neck. While L.E. Wilson focused on hand dies requiring the use of an arbor press, Neil Jones adapted the design to standard 7/8-14 presses. Both makers still turn out beautifully machined dies that are highly favored by precision reloaders.

What's interesting is that the interchangeable bushing die design has recently been picked up by major firms such as Redding and Hornady, making this advanced design more well known and more available to the average handloader.

What's the advantage of interchangeable bushing dies? Well, it's math time and you can easily make these same measurements with your own dies. In fact, you should. It's a very educational exercise.

The following measurements were taken from once-fired brass in a Model 70 Winchester .308 Featherweight, which was then sized in a standard RCBS full-length sizing die.

Neck diameter of the loaded .308 round: 0.336"

Neck diameter after firing: 0.349"

Neck diameter after sizing with expander button removed: 0.329"

Total reduction of neck after sizing: 0.020"

At this point, we have worked the brass down .020". Now we draw the expander button (measuring 0.307") back through the neck and increase the neck diameter of case to 0.335". In short, we have worked the brass down and then back up .026" (actually a bit more because of the brass spring back).

A More Modest Approach

With a bushing die, the outside neck diameter of the loaded round is taken as a constant reference point: 0.336". A hushing is selected with an inside sizing diameter 0.002" to 0.003" smaller than the neck of the loaded round -- 0.334".

Neck diameter after firing: 0.349"

Neck diameter after sizing with 0.334" bushing: 0.335"

Total reduction of neck after sizing: 0.014"

In this case, the brass in the neck has been worked down only .014", and the use of an expander button that can create distortion and concentricity problems all of its own has been eliminated. (Redding and Hornady do offer expander buttons in their die lines to add uniformity to cases that vary in neck thickness.)

The advantages of modern bushing dies that are available in increments of .001" are that neck sizing can be minimized, brass worked less, neck concentricity maintained, and expander buttons eliminated in most cases.
Uniformity of the brass you begin with is the real challenge. The most uniform brass lately comes from either Lapua or Norma. It's pricey, but it's quality. You need to begin with brass that varies not more than 0.003" in the neck. If it does, we suggest using Sinclair's power screwdriver system to turn your necks to a uniform thickness before employing bushing dies.

When neck sizing only with either bushing dies or standard neck sizing dies, the shoulder will progressively move forward, so eventually you will have to full-length resize or use a Neil Jones or Hornady shoulder/neck-style sizing bushing to set the shoulder back 0.002" to 0.003". In fact, Neil Jones recommends setting the shoulder back every time the neck is resized to maintain its fire-formed position. Jones, Redding and Hornady also offer full-length sizing dies that incorporate their interchangeable neck bushings.

Bushing dies represent one of the great advances in precision reloading. For the serious handloader, they're an invaluable tool for maximizing the accuracy of ammunition while prolonging case life. By all means send for the catalogs of Neil Jones, L.E. Wilson, Sinclair, Redding and Hornady, with their detailed descriptions of bushing dies and recommended reloading procedures.

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