Neck Turning Sinclair Style?

[antelopedundee]

Just got some items for Sinclair neck turning. For now I'll be sticking to .25-06 and 6.5-06 cases. To set up the die with an expander mandrel I assume to run a case all the way to the top of the press stroke and screw the die[sans mandrel] down until it contacts the case mouth and back off a turn or 2.

With the NT-1000 turner is there a preferred setting of the mandrel as a stop so that all cases get turned the same? Like the shoulder on the mandrel being flush with the inner surface of the turner body? Or as I expect, some trial and error rules the day? I'll be setting up the unit with some junk cases.

With .256 or .263 neck expansion, would you resize to a smaller neck diameter for hunting type loads or just use as is?

 

[adamsgt]

Well, the case mouth will sit against the shoulder of the mandrel and the mandrel will be moved in or out to determine how far along the neck you cut. Consensus is to just cut barely into the neck/shoulder junction

 

[retired]

for hunting rifles i would shoot for about a 50% contact/cut.
under size, size with their expander, turn on their turning mandrel
2 or 3 thous is plenty of neck tension, recoil and bullet weight is the issue

 

[antelopedundee]

Is it preferred to hold the case and turn the cutter or hold the cutter and turn the case? Prolly don't really matter I'd posit. So far so good. Probly order another cutter and have one for each caliber. FWIW I'll be loading 6.5-06 hunting loads into nickel plated cases just to make it easier to distinguish from .25-06 loads.

 

[retired]

i think you will have issues with nickle plated brass.
hard brittle
hopefully others well jump in

Is it preferred to hold the case and turn the cutter or hold the cutter and turn the case? Prolly don't really matter I'd posit. So far so good. Probly order another cutter and have one for each caliber. FWIW I'll be loading 6.5-06 hunting loads into nickel plated cases just to make it easier to distinguish from .25-06 loads.

 

[antelopedundee]

i think you will have issues with nickle plated brass.
hard brittle
hopefully others well jump in

I wasn't planning to turn the nickel plated stuff. Hopefully it will still shoot decent. If not, it stays home. They say that nickel plated cases will end up wreaking havoc on sizing dies. I assume the nickel flakes being harder than the die surface will eventually abrade them.

 

[brickeyee]

I wasn't planning to turn the nickel plated stuff. Hopefully it will still shoot decent. If not, it stays home. They say that nickel plated cases will end up wreaking havoc on sizing dies. I assume the nickel flakes being harder than the die surface will eventually abrade them.

Nickel plated cases will knock the cutting edge off real fast.

Like the first turn on the steel cutter.

The stop is on the mandrel.
You adjust it so the case mouth stops on it.

The little step on the mandrel.

My cutter actually has a 1/1,000 dial indicator opposite the cutter to monitor the process.

I use a 1/10,000 indicator to measure case wall thickness.

A slightly undersized (I use about 0.010) allows easy rotation of the case to check uniformity.

You zero the indicator on the side of this mandrel than measure all the way around.

When taking off more than abut 1/1,000 from the neck doing it in two stages gives better uniformity of surface and cut.

First cut gets it down to 1.0/1,000 over.
Final cut to desired diameter.

Note that most 'standard' chambers tend to be a little oversize and neck turning shells for them can make problems worse.
They will need at least a firing to expand back to actual chamber size.

There are some advantages to well executed tight neck chambers.
The uniformity of the neck wall thickness ensures the bullet is truly centered up in the bore
instead of being eccentric by the variation in the wall thickness.

 

[antelopedundee]

Nickel plated cases will knock the cutting edge off real fast.

Like the first turn on the steel cutter.

The stop is on the mandrel.
You adjust it so the case mouth stops on it.

The little step on the mandrel.

My cutter actually has a 1/1,000 dial indicator opposite the cutter to monitor the process.

I use a 1/10,000 indicator to measure case wall thickness.

A slightly undersized (I use about 0.010) allows easy rotation of the case to check uniformity.

You zero the indicator on the side of this mandrel than measure all the way around.

When taking off more than abut 1/1,000 from the neck doing it in two stages gives better uniformity of surface and cut.

First cut gets it down to 1.0/1,000 over.
Final cut to desired diameter.

Note that most 'standard' chambers tend to be a little oversize and neck turning shells for them can make problems worse.
They will need at least a firing to expand back to actual chamber size.

There are some advantages to well executed tight neck chambers.
The uniformity of the neck wall thickness ensures the bullet is truly centered up in the bore
instead of being eccentric by the variation in the wall thickness.

Thanks for the info. Got it figured out. I got the NT-1000 unit. I used a .012 thickness gauge to set up the cutter. I had some new PPU Priv Partizan .270 cases sized down to .264. On some almost nothing was removed, but others had almost 100% removal of something. The stop at the neck/shoulder junction is near perfect. The one gripe I have is that it would be nice if the cutter would make a slightly wider path, but I suppose there is a reason that it is the way it is. Seems like a wider swath would give a more uniform surface. This setup will be used for 6.5mm cases. I ordered another cutter to be dedicated to .25 caliber stuff.

Left is a new case; right is one fired several times.

 

[brickeyee]

The one gripe I have is that it would be nice if the cutter would make a slightly wider path, but I suppose there is a reason that it is the way it is. Seems like a wider swath would give a more uniform surface.

A wider cut would greatly increase the amount of force required to make the cut.
This would also increase the clamping force required to hold the shell from turning in the clamp.

I use a very small amount of cutting lube to improve the surface finish.

Make sure the cutter is clamped into the tool very tight.

Use a high quality hex key to tighten down the set screw.
It needs to flex a little bit to make the screw tight.

 

[antelopedundee]

A wider cut would greatly increase the amount of force required to make the cut.
This would also increase the clamping force required to hold the shell from turning in the clamp.

I use a very small amount of cutting lube to improve the surface finish.

Make sure the cutter is clamped into the tool very tight.

Use a high quality hex key to tighten down the set screw.
It needs to flex a little bit to make the screw tight.

Right. The reeded screw for tightening the case in the clamp is useless and murders one's fingers. I found using the allen screw to work best. Fortunately I had a wrench with a sort of handle from a book shelf assembly project that worked perfect.

 

[brickeyee]

Right. The reeded screw for tightening the case in the clamp is useless and murders one's fingers. I found using the allen screw to work best. Fortunately I had a wrench with a sort of handle from a book shelf assembly project that worked perfect.

I generally throw those out without a second thought and use a Bondhus
key or driver.

Having high quality hex tools is worth the additional money.

Correctly hardened, correctly sized.