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Sinclair or Hornady oal gauge

Ayoung1

Sergeant
Full Member
Minuteman
Apr 24, 2017
198
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I'm trying to decide which of these to get, I like the Sinclair because it doesn't require a bunch of threaded cases. Which do you use and what's the pros and cons of each?
 
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I prefer the Hornady gauge over the Sinclair because it references the bullet ogive. The Sinclair requires you use the length of the bullet, which can vary quite a bit bullet to bullet. I bought a tap (it's an odd size, but found one on eBay) and make test casings myself.
 
The simplicity of the Hornady for me, run it 3 times on a new chamber, get an average, shoot a few test rds, redo, you're looking for a baseline number, not exacts, you still need to find the exact seat depth your gun likes by adjustment.
 
I use a little of both. I use the Hornady tool when taking readings off the rifle but use the Sinclair comparator insert to do the actual measuring.

One downside to the Hornady tool is that THEIR case can vary in length (headspace) from a fired case from YOUR rifle. In my case I have to add .004' to the CBTO measurement I get when using the Hornady case. Making your own case by using a case fired in your rifle will negate the need for this correction.

I don't worry about their special tap size. I drill out the case head so it will just slip over the threads on the Hornady tool. I rub a little wax on the threads of the Hornady tool and then apply some J-B weld to to the waxed threads and a thin coat on the inside of the drilled out part of the case head. Put the case on the tool, wiggle back and forth a little to make sure the J-B is filling threads and case is seated. Put aside and let cure. Next day just unscrew case. Works for any caliber I have whether or not Hornady makes the "Specially Prepared Case". No waiting either other than cure time.
 
I drill out the case head so it will just slip over the threads on the Hornady tool. I rub a little wax on the threads of the Hornady tool and then apply some J-B weld to to the waxed threads and a thin coat on the inside of the drilled out part of the case head. Put the case on the tool, wiggle back and forth a little to make sure the J-B is filling threads and case is seated. Put aside and let cure. Next day just unscrew case.

Excellent tip.

 
I use a little of both. I use the Hornady tool when taking readings off the rifle but use the Sinclair comparator insert to do the actual measuring.

One downside to the Hornady tool is that THEIR case can vary in length (headspace) from a fired case from YOUR rifle. In my case I have to add .004' to the CBTO measurement I get when using the Hornady case. Making your own case by using a case fired in your rifle will negate the need for this correction.

It's still just a baseline measurement to go off, whether your bullet is .008" off by your measurements, but really .012" off is irrelevant. You have a number to go off now. Even if you shot your barrel out in 6 mos and had another chambered, just from reamer wear it will never be the same.
 
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I'd imagine the "technique" involved in feeling your way to the lands lends itself to a bit of error too.
 
I prefer the Sinclair. One, it uses my fire formed cases, can't fireform the Hornady cases. Two, I can get a better center-of-the-case measurement, the Hornady tool has a cutout but I still think the Sinclair is more centered. Using a bullet comparator attached to my micrometer gives me base to ogive measurements. Honestly, either tool will get you a pretty decent measurement.
 
I'd imagine the "technique" involved in feeling your way to the lands lends itself to a bit of error too.

I kind of like to give the adjusting rod in the Hornady tool a tap or two with a screw driver handle. Not hard, just enough of a tap that the bullet is definitely against the lands but not so heavy as to engrave the bullet. I can tell by the sound of the plastic handle hitting the plastic rod that there is no more movement. From "mushy sound" to "solid".

Readings are very repeatable when I do this.
 
I tried this but I'm not sure how to get the ejector out of my Tikka ctr bolt. It is hard to get a feel with the ejector putting pressure on the case.

Not familiar with the tikka bolt. Maybe try a sharpie and see when you stop getting marks from the lands all the way around on the bullet? I would expect some minor scratching from chambering but you should also be able to see the five or six square faces from the lands when you're in them and when they start disappearing should be just about as accurate as the hornady or Sinclair gauge would be that are based off of feel or jamming of the bullet instead of actually just touching.
 
I prefer the Sinclair. One, it uses my fire formed cases, can't fireform the Hornady cases. Two, I can get a better center-of-the-case measurement, the Hornady tool has a cutout but I still think the Sinclair is more centered. Using a bullet comparator attached to my micrometer gives me base to ogive measurements. Honestly, either tool will get you a pretty decent measurement.
I sent two fire formed Hornady cases to Hornady, and for $15 the threaded it for me. MOr eccurate then me doingti I am sure. Works like a charm.
 
Cheat! I didn’t take my ejector out either but I did a work around that made it easy. I did destroy a case tho but I got a repeatable reading that I’m confident in. Worked a treat! Just make sure the dummy round has low runout or that can give false readings.
 

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The cases that are fire formed that are being used... you guys don’t FL resize them correct, you just neck up size them enough so the bullet has just enough tension to hold the bullet in place when using whatever method/tool (hornady, Sinclair, is wheeler method)... correct?
 
The cases that are fire formed that are being used... you guys don’t FL resize them correct, you just neck up size them enough so the bullet has just enough tension to hold the bullet in place when using whatever method/tool (hornady, Sinclair, is wheeler method)... correct?
No, you do NOT resize it - fire formed means it has expanded after firing to conform to your chamber, and I t should be a first-time fired case - factory or reloaded. Having been fired, the bullet will easily slip in and out of the out of the case with no need to expand. . However, you need to have the base drilled and tapped to fit you OAL gauge.
 
I prefer the Hornady gauge over the Sinclair because it references the bullet ogive. The Sinclair requires you use the length of the bullet, which can vary quite a bit bullet to bullet. I bought a tap (it's an odd size, but found one on eBay) and make test casings myself.
Although the directions say OAL, theres no reason you can't just use a BTO measurement instead. Works just fine and less moving parts, so i find more consistent results w/ the Sinclair.