[azcowboy]

I see Sinclair now has bump guages to measure headspace, they measure off the slope of the shoulder instead of the datum
line. Do you think these are more or less accurate than the Hornady inserts, I do know someone on here mentioned that they were using them and getting different results between the two. Anyone have a theory whats going on ( Tim W.)

Rhett in Az

 

[borderpatrol]

My personal opinion is that Sinclair's system makes the most sense to me. It actually measures based on the chamber's design. Both systems work just fine. Because people get different readings using the different tools doesn't mean that one is better or more accurate. Just don't mix data from one system with the other. They both work as intended.

 

[EWP]

I have the Sinclair Bump gauge inserts for my Hornady Bump gauge set and you wouldn't believe how much better the Sinclair gauge works. You can measure the shoulder of a fired piece of brass with both the Hornady insert and the Sinclair insert, bump the shoulder back .005" according to the Sinclair insert and the Hornady insert will measure you only bumped the shoulder back .001". The Hornady inserts are junk and there is no telling how much people have been bumping there shoulders back to get a .005" reading from the Hornady insert.

I recommend all to stop using the Hornady Bump gauge inserts if you have a Hornady Bump Gauge set and buy the Sinclair inserts for your 6.8 and .223, you'll be amazed how much better it reads and it also gives you a feel of how straight the shoulder is with the case when you turn the case in the calipers since you are turning against the actual shoulder instead of a single point on the sholder like the Hornady insert fits.

Now the Sinclair .277 cal Bullet Comparators are another story, instead of measuring from the ogive like it's supposed to it swallowed the whole bullet and hit the case mouth. In there defense I think they are designed for the larger .277 cal bullets that the .270 shoots, not the short light weight bullets the 6.8 shoots. I have already discussed this with them and made some dummy rounds using 110gr Nosler Accubonds seated at 2.285" and I also included a Hornady 110gr BTHP for them to redesign the insert to fit our smaller bullets. I'll let everyone know when they have the problem fixed and have them just for the 6.8, until then the Hornady insert does work OK for this task. The Sinclair insert will be much better though since it will fit the ogive profile like the bump gauge fits the shoulder of the case and we should get much more accurate seating depths when finished.

 

[jasonpeterson]

The only thing is if you measure with the hornady 1st and then bump back then only measure with the hornady. You will still have set it back the same amount. If you use both you are comparing apples and oranges. I have both and they are both just as consistent. They do give different readings because they work differently. If you stick to one. It works. I wouldn't stop using the hornady just because they read differently.

 

[EWP]

I am comparing apples to apples, you misunderstood what I am saying.

Take a fired cartridge and measure it with the Hornady gauge, then measure it with the Sinclair gauge. Now you have the fired measurement of that case with both gauges.

Now bump the shoulder back .005" using the die setting from the Sinclair gauge.

Now measure the headspace using the Hornady gauge, it reads you only bumped the shoulder back .001" compared to the measurement you took using the Hornady gauge to begin with. So according to this gauge and measurement you need to bump the shoulder back .004" more to reach a total of .005" headspace using only the Hornady gauge.

But you take that same case that is reading the shoulder bumped back .001" and measure it with the Sinclair gauge and it reads that the headspace (shoulder bumped back) is .005".

So if you ONLY had the Hornady gauge you would think you only bumped the shoulder back .001" and would set your die down more to get the other .004" needed to get the .005" total shoulder bump, when in fact you have already bumped the shoulder back .005" according to the Sinclair gauge.

So how is this comparing apples to oranges, both measurements were taken with both gauges before and after sizing and according to the Sinclair gauge the shoulder(since that is what it's really measureing) has been bumped back the .005" and the Hornady reads that it needs .004" more.

Both measurements were taken with the same brass using both gauges before and after, one says it's good and the other says it's not.

So how does one gauge say it's bumped back .005" and the other say it's only .001" yet you say both gauges read the same and are correct?

 

[marinesg1012]

I want to get a set of these I think I will call sinclair tomorrow.

 

[jasonpeterson]

I misunderstood that you were taking beginning measurements with both gauges. Both of mine are pretty close. So your hornady gauge causes you to set the shoulder back too far. I'm not seeing the same variances. Sorry I misunderstood what you were saying.

 

[mogunr]

http://www.sinclairintl.com/product/5574/Case-Gauges-Headspace-Tools

Is this the gauge that you all are talking about? Looks a lot similar to the Hornady.

 

[EWP]

http://www.sinclairintl.com/product/5574/Case-Gauges-Headspace-Tools

Is this the gauge that you all are talking about? Looks a lot similar to the Hornady.

I have the Hornady Bump Gauge set so all that is needed is the insert to fit the Hornady holder. The Sinclair insert fits the shoulder profile and gives a much better measurement of how much the shoulder is really being bumped back to minimize case sizing to save your brass from unneeded sizing.

http://www.sinclairintl.com/product/11264/Case-Gauges-Headspace-Tools

 

[mogunr]

I have the Hornady Bump Gauge set so all that is needed is the insert to fit the Hornady holder. The Sinclair insert fits the shoulder profile and gives a much better measurement of how much the shoulder is really being bumped back to minimize case sizing to save your brass from unneeded sizing.

http://www.sinclairintl.com/product/11264/Case-Gauges-Headspace-Tools

Gotcha.... it's a difference in the inserts. i wonder how a top notch company like Hornady could be off like that? QC slipping a bit? I guess now I'll have to buy the inserts and do my own checking.

 

[dlance13]

Not sure how much R&D Hornady has put into the gauges since they were originally by Stoney Point.

 

[EWP]

And some chambers may cause a different reading also, I could see were a chamber that is tight at the datum point not letting it move much but the actual shoulder still being pushed out to fit the rest of the chamber(.005" in my case).

My fired brass only has .005" more shoulder length than a new piece of the same brass(on average of about 10 pieces, most being the same), so I bump the shoulder back .003-4" to leave the shoulder .001" longer than when it was new. I feel this is a safe amount of headspace with the minimum amount of sizing on my brass.

I have my bump gauge zeroed at what the shoulder length is on new LC 07 NATO brass (since I have 900 pieces of new for loading after I figure out good loads for each of my bullets), and gauge all my headspace based on that measurement. When I get once fired LC brass I FL size it to the .004" headspace in my gun and it all runs just fine in both of my AR's(the 6920 has .008: headspace so the sized brass leaves .007" headspace in it).

This info is on .223/5.56 brass but I use the same principle on my 6.8, I have a separate caliper and gauge for it zeroed at what new SSA and Hornady brass headspace length and bump the shoulders on my fired rounds back .004" based on that #.