Hello,

here's my situation and please help me since elk hunting starts in 3 weeks.

I recently had a new barrel installed on my M70 and it's a 338 Remington Ultra Mag. The fired factory cartridge measure at .368 on the neck.

The virgin brass measure at .365 at the neck expanded with a Wilson expander.

Both the fired and virgin brass neck wall thickness are at .012,

What size bushing do I need for my Redding bushing dies?

Thank you!

.360

I usually measure a loaded round and subtract the desired neck tension, .002. Also if your fired brass is .005+ larger than your bushing choice you should size in two steps. Sizing down more than .005 at a time can cause some problems with concentricity.

quote:

Originally posted by steve4102:
I usually measure a loaded round and subtract the desired neck tension, .002.

This is indeed the way to do it, although I normally work with more than .002" of neck tension - in particular in a caliber as lively as the .338 UM. If you try to go as low as .002" you may well come to grief when your cases workharden a bit...

In general, and even more so if you are in a hurry and can't afford another week's wait for something you could have bought in the first place, it is rare one ends up with exactly one bushing for a given caliber/case brand combination. First off, you don't strictly know if varying neck tension might have an effect on accuracy. Secondly, as mentioned above, once your brass starts to workharden it is likely you may want a bit more sizing to overcome brass springback. Finally, I have never quite understood why, but I have experienced necks sized with bushing dies come out with dimensions which made no sense (e.g smaller) compared to the nominal size of the bushing. Were Redding's bushings mislabelled, I don't know??

If I was the one in this situation, I'd measure the neck diameter of 3-4 loaded rounds, and buy bushings .004, .005 and either .003 or .006 smaller than loaded round diameter - depending on whether you like to work with less or more tension.

- mike

You might want to use Wilson bushings. They have a larger lead in radius and will probably make for more concentric necks.

Wilson and Redding bushings are the same; they fall off the same production belt.

If you're not turning your necks, it's a good idea to use an expander button. When doing so, there is no sense in sizing the necks down any further than to the point where the expander will experience the least bit of tension. This usually the case when choosing a bushing which is .002 or .003 smaller than the loaded round. The more workhardend a case gets the tighter the bushing will have to be.

Norseman, I don't mean to get off the subject but did you ever find those Rem 7 1/2 primers that you were looking for?

quote:

Originally posted by McFox:
Wilson and Redding bushings are the same; they fall off the same production belt.

If you're not turning your necks, it's a good idea to use an expander button. When doing so, there is no sense in sizing the necks down any further than to the point where the expander will experience the least bit of tension. This usually the case when choosing a bushing which is .002 or .003 smaller than the loaded round. The more workhardend a case gets the tighter the bushing will have to be.

No they are not.
I have both brands and they are significantly different. Ask Redding or Wilson if you don't believe it.
Differences

1. Surface finish
2. Font used to mark the diameter.
3. Reddings have ring cut on the outside diamter.
4. Reddings have a smaller radius on the edge of the bore.

I load with my bushing dies as close as possible to .003" smaller than the bullet slip fits into the case neck. This bushing is usually .004" smaller than the initial slip fit because there is .001" of sping back.

I do not use any expander buttons with bushing dies. I decap with a universal decapping die.

Bshooter, no I never did find any Rem 7 1/2 primers even I check out Cabela's & Sportman's Warehouse in Boise area of Idaho.

To all those that responsed,
please allow me to re-explained.

I have about 120 "VIRGIN" 338 Remington Ultra Mag brass with a neck wall thickness of 0.12 with a outside DIAMETER of .0365 after being run through a Wilson expanding mandrel.

Howevever, with factory loaded ammunation by Remington, my fired case's have a neck wall thickness of .012 with a DIAMETER of .368

So what should I do? go .003 smaller bushing for the fired brass or should I go .003 smaller for the VIRGIN brass after being expanded?

Or go .003 smaller bushing for the loaded round in a VIRGIN brass

Or go .003 bushing smaller for the fired brass?

quote:

Originally posted by Norseman:
Or go .003 smaller bushing for the loaded round in a VIRGIN brass

Measure loaded round neck diameter and subtract the tension you'd like to achieve (figure approx .001 brass springback - varies as cases get workhardened).
- mike