Being too clever for oneself?

[LRHWAL]

In South Africa we have an Afrikaans expression: "Slim vang sy baas" - literally translated " Clever catches it's (his) boss".

This is just a comment to maybe remind us that we need to try to match certain techniques with certain shortcomings in our equipment / skill etc. Not to suggest that we accept anything less that perfect though, but to try to match the processes.

I rate my reloading skills as above average (learnt a bunch here, thank you!). I use the "better equipment" and "tools" that I can afford and try to keep learning and reading as I go. My results are generally pretty good and I'm probably even a little too compulsive about some of the things that I do in the loading process.

I've not been able to get a run out gauge here and have a friend making me one - that will no doubt answer many questions, and give rise to a bunch that I'll ask here, but that's a thread for another time.

Anyhow, the point is that I bought a Wilson 30° uniform inside deburring cutter. All good and I like the trimmer very much.

I neck sized some 3 times fired cases in a Redding bushing neck die. Trimmed on the Wilson and went to work inside deburring. Cases are sorted Winnie (.300 WM) with less than .002" neck thickness variance.

Imagine my surprise to find that the cut of the chamfer was totally uneven (I'd love to blame the tool), implying to me that the necks are out of alignment (I'd think). So I'm cutting around a different axis to where the neck is centred; tool centre and neck centre don't co-incide. This means that the bullet release will likely be less consistent than with my previous hand turned de-burrer. I suppose that at that angle the 2 thou neck thickness variation can make a bit of a visible difference - but not this much.

Just a thought - the inconsistencies in certain processes may be treated in a less foregiving fashion by certain precision tools - in fact I guess you may be worse off. Sure, I now know that there's a problem that I suspected anyway, but that's another point altogether.

Expect a bunch of run out questions shortly! :-)

[Winchester 69]

There are screws through the base that retain the tool parts. Check that these are tight. I can't imagine what else would cause misalignment of this tool, unless the brass is banana-shaped. Since you are neck-sizing, is it possible that the neck of the brass is not perfectly aligned with the case body? If something has been mis-made, then notice to Wilson would be in order.
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[Delta Hunter]

I don't have that particular tool, but here's my take on it. You may be sizing your brass with perfect concentricity on the outside of the neck, but with that die the difference in neck thickness will be tranferred to the inside of the neck and therefore the inside surface of the neck will not be concentric to the axis. So, when you chamfer the neck with the Wilson tool, there's no way the chamfer is going to be even around the mouth of the case. This apparently you already know.

I've used the Redding neck die you're talking about and never got the desired concentricity I wanted without turning the case necks first. So, either turn the necks or use a handheld chamfer tool. Actually I'd turn the necks regardless of what else you do in order to get less bullet runout.

Then again, you could just get a Lee collet neck die which indexes off the inside of the neck instead of the outside.

[LRHWAL]

Originally Posted by Delta Hunter

You may be sizing your brass with perfect concentricity on the outside of the neck, but with that die the difference in neck thickness will be tranferred to the inside of the neck and therefore the inside surface of the neck will not be concentric to the axis.

Thanks for the replies.

That's partly my take on it too. Just to be clear, I'm not doubting the Wilson tool at all.

I'll run a K&M mandrel in a few necks over the weekend (don't have a die in 300WM with an expander) and see how that changes things. However, the relatively consistent neck thickness makes me wonder if that's the "full story".

I'm not wanting to get ahead of myself with a thread for later once I have a runout gauge, but I suspect that the necks are a bit shaped like this () on fired brass. I'm not sure why - maybe the chamber has too much clearance for the thinnish Winnie brass (have no idea if that will do it), but the runout gauge will tell me if that's so. That may increase runout and lead to peculiar results when run into a neck only sizer.