Thread: Redding S Type Match Dies - Bushing or not?

Originally Posted by Stag

So…..

I have opened the die and you can see the sizing is from the bottom of the neck down. That said the neck has to pass through top of the shoulder in the die so likely some sizing occurs.

My bushing is .291 and the new chamber is .298

Would it be correct in saying that I should be running a .296 bushing?

No, in the instance there is no relationship between the brass and the chamber other than one sits in the other. You need to either know the wall thickness atvthe neck and the projectile OD, or the easier method is measure the neck of a loaded round as this will be the sum of the two. Measure 5-10 off them and take the average. This is your loaded neck OD. For the brass to grip the projectile you need neck tension. Essentially it is an interference fit between the case neck and the projectile. I would sugest anything from 2-4 thou for a hunting rifle, and maybe 1-2 for a target rifle. I don't know what a 6.5 is going to measure but an example may be if a loaded round measured 0.295" and you wanted 2 thou tension your bushing would be 0.293". Expect about 1/2 thou spring in the brass so really a 0.293" bush may give closer to 0.2935" or only 1-1/2 thou neck tension.