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Sinclair Mandrels

Drewdemon

Online Member
Full Member
Minuteman
Feb 20, 2017
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I purchased a carbide Sinclair mandrel last year in 6.5CM (.264). If you read the description is says "Sinclair expander mandrels are made .001" smaller than bullet diameter." That said when i measure it with my Mitutoyo it measures .262, that's .002 not .001. Thinking i order the neck turning mandrel i ordered one recently but had the same result.

Any one else see this?
 
Same thing for me. Ordered expanding, not knowing I wanted neck turning until doing more research. Then was pleasantly surprised to find I had a .262 Mandrel.
 
I have expander and neck turn mandrels for several calibers. I'll measure a few when I get home
 
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I called them yesterday. They are doing a "tech-check" before sending a replacement. We'll see what happens.
 
The carbides are all .002 under bs the steel that are .001
 
The carbides are all .002 under bs the steel that are .001

That used to be the case, but I think they have started to offer carbide expanding mandrels in addition to the carbide turning mandrels. Brownell's lists both on their site.
 
Both sizes are available in stainless and carbide.
What I’m saying is I have carbide and steel. All my steel measure .001 under and all my carbide measure .002 under. That’s testing 5 sets
 
I use a Titanium Nitride Turning Arbor from 21st Century Reloading. Slick as butter and nice guy. Mom and pop, made in USA biz......
 
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What I’m saying is I have carbide and steel. All my steel measure .001 under and all my carbide measure .002 under. That’s testing 5 sets

There are two types of mandrels that Sinclair sells which were all part of their neck turning tool kit... Expanding and Turning mandrels. They are meant so you expand the brass with the larger one (expanding), then use the smaller mandrel (turning) for when you spin the brass on the neck turner for cutting.

The expanding mandrels are 0.001 under bullet dia, the turning mandrels are 0.002 under. You can buy both steel and carbide in either size.
 
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What I’m saying is I have carbide and steel. All my steel measure .001 under and all my carbide measure .002 under. That’s testing 5 sets

And what I'm saying is you bought the wrong one. "Neck Turning" is .002" under and "Expander" is .001 under.
 
I measured all my steel mandrels last night. The expander mandrels were all 0.001" thinner than the caliber diameter and all my neck turning mandrels were between 0.002" and 0.0025" thinner
 
21st Century is about to list mandrels in .0005" increments. Steel for now as I know, and no clue how far below caliber dia they will go, but this will give some serious options for people using this method.
 
when i measure it with my Mitutoyo it measures .262, that's .002 not .001.

Your Mitutoyo what though? Calipers aren't always the most accurate for measuring a round object down the the thousandth especially if you don't have a real good feel and or you're over squeezing. Did you try an OD mic or checking your calipers against a standard?
 
I talked to the folks at Sinclair and they worked with me on the phone. After talking to them i started to doubt the mandrel was the issue. Took my Mitutoyo (CD-6 ASX) calipers to a friend who is a mechanical engineer and after some testing discovered it was the calipers. Correcting them was an easy fix. "All" my mandrels are fine. The support guy at Sinclair was great.
 
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I talked to the folks at Sinclair and they worked with me on the phone. After talking to them i started to doubt the mandrel was the issue. Took my Mitutoyo (CD-6 ASX) calipers to a friend who is a mechanical engineer and after some testing discovered it was the calipers. Correcting them was an easy fix. "All" my mandrels are fine. The support guy at Sinclair was great.

I wish Mitutoyo had a “spa” clean, tune and calibration program......I know a knife maker who had that done at Starrett. When you use them a lot they really need that once in a while.
 
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Question, did you carbide mandrel truly element the need for case lube? Thank you.
 
Question, did you carbide mandrel truly element the need for case lube? Thank you.
Did you mean: "Did your carbide mandrel truly ELIMINATE the need for case lube?

I would like to know that as well.
 
I still need to use lube with the carbide mandrel, but less then the SS one.

Mike
 
I have used the carbide and the titanium nitride and the Ti seems much better to me. I use just a tiny bit of lube.
 
21st Century is about to list mandrels in .0005" increments. Steel for now as I know, and no clue how far below caliber dia they will go, but this will give some serious options for people using this method.

I so much want this to be true but I'll believe it when I see it. I was told they would be available to order on their website sometime the week of April 7th but while they show a photo of a set with a header proclaiming "New" on the website, clicking the link is a disappointing letdown as it just says "Coming Soon."
 
Old thread but I recently purchased Sinclair neck turning mandrels that are advertised to be .002” smaller than bullet diameter. I bought one in .223, .264, .284, and .308. They all come in incorrectly sized at .003” under bullet diameter. I measured bullets to verify and sure enough.

I’m going to return them and get the expander mandrels which are advertised at .001” below bullet diameter. Maybe these will come in .001” smaller and give me my .002” under diameter that I want. Just a heads up for any one that is considering these.
 
Old thread but I recently purchased Sinclair neck turning mandrels that are advertised to be .002” smaller than bullet diameter. I bought one in .223, .264, .284, and .308. They all come in incorrectly sized at .003” under bullet diameter. I measured bullets to verify and sure enough.

I’m going to return them and get the expander mandrels which are advertised at .001” below bullet diameter. Maybe these will come in .001” smaller and give me my .002” under diameter that I want. Just a heads up for any one that is considering these.
All my Sinclair carbide expanding and turning mandrels are dead on as advertised. At least with my Starrett .0001" micrometer. I bought them some time ago. so not current production.