In consistent reading on Hornady Headspace comparator

[Migolito]

I'm pretty new to using a HS Comparator. I have/use the Hornady aluminum head space comparator and can't seem to get a consistent reading. I.e I'm loading a 145LRX 20 thou off so 2.6460. I'm using a clean Redding micrometer Comp die, a MEC press and using a Mitutoya caliper. I measure every few rounds as I seat for consistency. I'm coming up with 2.640, 2.650, 2.630 etc.

What am I missing? I can 'feel' the bullets kinda stick to the comparator. Feels like the copper and aluminum aren't real smooth together. I'm thinking the comparator isn't as accurate as I'd assumed. Any ideas? I'm looking at the Short Action Customs SS comparators.

 

[greghost]

Get a Sinclair comparator they are stainless steel from Brownells

 

[Migolito]

Do you know if the Sinclair can use the Hornady base

 

[cdgaydos]

Check that you are lined up square in the calipers… make sure the comparator has been installed square…

I put everything together and bring the calip together a little and tighten the set screw a little at a time making sure nothing is bound…

When taking a measurement it is absolutely necessary to make sure the head of the case is square and centered on the anvil.

Also, check primer seating variation…

 

[6bra1k]

i have used the alum for years...may i suggest just practice...and is your primer actually below flush.
is your seating die set up to be at the top of the stroke,,,

 

[greghost]

Do you know if the Sinclair can use the Hornady base

Yes

 

[Coyotefurharvester]

Do you see the same large range measuring coal of same cartridges? Are the case body(headspace) lengths changing after seating? Because I believe you are using the bullet comparator inserts after seating bullets(not the headspace body).

 

[LCazador]

The bullet comparator and headspace gauge are not one and the same. With the measurements you've given, differing by .010" it sounds like your caliper is whacky and maybe seating die too!

 

[Migolito]

Great info!
Yes, I'm using the Bullet Comparator to set the Jump( I thing I screwed up my original terminology ) So, yes, a 20 thousandths jump. Ive definitely squared up the base of the comparator anvil.

I'm thinking maybe the one size for the 7mm is a little off. So, as I square up and turn the cartridge I inducing whatever the variance is where the bullet touched the comparator.
I'm going to order some SInclair comparator and post up what I find. IF that doesnt work, I shoot a Vid and ask you guys again.
Thank you

 

[CSLR grandpa]

If you are checking bullet olive, turn the body of the comparator over, it has a thin and a thick side for the set screw.
(Top Grade Ammo)

 

[Bill Norris]

I'm pretty new to using a HS Comparator. I have/use the Hornady aluminum head space comparator and can't seem to get a consistent reading. I.e I'm loading a 145LRX 20 thou off so 2.6460. I'm using a clean Redding micrometer Comp die, a MEC press and using a Mitutoya caliper. I measure every few rounds as I seat for consistency. I'm coming up with 2.640, 2.650, 2.630 etc.

What am I missing? I can 'feel' the bullets kinda stick to the comparator. Feels like the copper and aluminum aren't real smooth together. I'm thinking the comparator isn't as accurate as I'd assumed. Any ideas? I'm looking at the Short Action Customs SS comparators.

When closing the calipers try to slip up on the ogive very easy to keep from jamming it too deep into the insert. It's very easy to go too far too fast. It takes a little effort and time to get a good feel for the tool. But, I agree the S S inserts from Sinclair seems to be easier to work with.

 

[6BRA]

Much better stuff than calipers out there. Accuracy One...Holland gold standard bullet comparator, Redding instant indicators...calipers leave too much room for human error..jmo

 

[Dave M.]

I'm pretty new to using a HS Comparator. I have/use the Hornady aluminum head space comparator and can't seem to get a consistent reading. I.e I'm loading a 145LRX 20 thou off so 2.6460. I'm using a clean Redding micrometer Comp die, a MEC press and using a Mitutoya caliper. I measure every few rounds as I seat for consistency. I'm coming up with 2.640, 2.650, 2.630 etc.

What am I missing? I can 'feel' the bullets kinda stick to the comparator. Feels like the copper and aluminum aren't real smooth together. I'm thinking the comparator isn't as accurate as I'd assumed. Any ideas? I'm looking at the Short Action Customs SS comparators.

The Hornady ones are junk. Save yourself the hassle and doubt and invest a few more bucks into SAC, Sinclair, 21st century, Accuracy One, etc

 

[6BRA]

For headspace/shoulder bump, I don't believe anything is as consistent as Redding Instant indicator....for setting jump it would be accuracy one. For bullet comparator...Holland gold standard...all use dial indicators..all are super accurate and super fast. None are 45 dollars.

 

[rijndael]

I find the SAC headspace measuring insert, with the built in shoulder, to be more repeatable and easier to use than the traditional datum style insert.

 

[rijndael]

FWIW: Before I got the SAC comparators, I tried the Sinclar ones. The Sinclar ones had machining flaws/dents on the critical surfaces. I returned and re-ordered and the new ones, those had flaws too. I don't know if it was a bad batch, or just typical COVID related drop in QC, but I was disappointed in them.

Here's a picture of the Sinclair dents. The one at 7:30, on the edge of the hole, was noticeable.

 

[GAnderson]

If you are checking bullet olive, turn the body of the comparator over, it has a thin and a thick side for the set screw.
(Top Grade Ammo)

CSL grandpa, It's shocking isn't it how many do not know that the slot in the body for the caliper anvil is offset and needs to be mounted one way for checking your length to touching the lands measurement and then turned over the other way to check your loaded round seating depth.

Gene

 

[SKWERLZ]

Make sure the primer is out
Spin it a bit to let it center up.
Consistent readings are combining the above with consistent pressure(not much) and feel.

 

[Dusty Stevens]

Its your bullets. Your seating stem contacts them at a different spot than the comparator. Measure the same one multiple times and see if you get the same measurement so you can rule out your calipers and comparator

 

[PJ1]

I have the same hornady hs comparator and tried the sac comparator ( I sent this back as quality was awful), and you usually have to guesstimate by rotating the cartridge and coming up gradually to the ogive. It is rather frustrating to say the least.

Now enter the AC1 bullet seating comparator.................Life gets a lot easier, but you still are going to get variance in the seating depth of 1-2 thousandths. Some has to do with manuf. and the rest is probably do to seating pressure. Even using Berger bullets, I have seen a difference in seating depths of 1-2 thou. For me it's just a fact of life and how much you want to drive yourself crazy with this stuff:

consistent base to ogive measurement

Seeking more consistent base to ogive measurements - is it the die or my own technique? Currently using .308 Forster BR seater die, have replaced the spring and the seating stem. Out of a typical batch of 25 reloads the base to ogive variance can be 0.003" with 155 gr Sierra 2156's...

forum.accurateshooter.com

Using a Wilson bullet seating die, I'm usually able to achieve a batch of ammo that has a spread of 10-12psi variance. The majority of my rounds are less than 3-5psi (0-0.0005" depth variance) for seating and that is where I really noticed the low es/sd's on the chrono. with sub .5moa. The above thread explains a lot of what I was seeing with regard to psi and bullet seating depth. Even at the higher psi's I am able to get at least 0.5moa. Sure it's a pain in the ass having to do all of this, but hearing that steel sing at 1000 yards is nirvana.

Lots of voodoo with this stuff and you have to find what works best for you............