Comparator trick

[Tesoro]

I've been doing this forever and claimed this trick. But then I just saw today that Hornady makes an anvil base. Must be something relatively new? Anyhow for those who didnt know get one!! It's easy to measure like in the second stock pic and be off a few thou by not being vertically aligned. And esp for batching bullets. Plus it is faster.

 

[jaytee]

I use the anvil base but I still find that I have to measure it several times and I usually hold the base up to the light to help check for it being flush. I can get as much as 3 or 4 thousandths variance.

 

[Metal God]

Yep , I’ve had the anvil for years so it’s not new .

 

[Tesoro]

I use the anvil base but I still find that I have to measure it several times and I usually hold the base up to the light to help check for it being flush. I can get as much as 3 or 4 thousandths variance.

Do you mate the top and bottom together tight before clamping down the screws? I am rarely off more than a tho or two with this technique. When I get ready to measure I twist the case with my forefingers on the base as it seats into the comparator. With some bullets need to use a diff size comparator than the caliber to get closer to the ogive.

 

[6BRA]

Calipers leave too much variation on misalignment. Not accurate enough..jmo

 

[Blackthorn]

I have a set of dedicated calipers for the comparator. I have the anvil as well. I use a machinists bar to adjust the alignment. It really speeds up with making sure everything is parallel and the caliper is reading correctly. The set screw on the comparator and anvil helps with fine adjustment on the caliper jaws.

 

[jaytee]

Do you mate the top and bottom together tight before clamping down the screws? I am rarely off more than a tho or two with this technique. When I get ready to measure I twist the case with my forefingers on the base as it seats into the comparator. With some bullets need to use a diff size comparator than the caliber to get closer to the ogive.

Not sure I'd say tight but definitely snug and I try to use that same force when measuring. And I do rotate the case to try to get it to settle. What I've found that seems to help some is to try to hold the calipers as verticle and plum as I can as I'm tightening or closing the jaws.

 

[Tesoro]

Well its not ideal but what most of us have to work with. And two or three thou variation is not gonna make a diff for 99% of us.

 

[Tesoro]

Yep , I’ve had the anvil for years so it’s not new .

Being a self professed garget freak I am amazed that I never saw this before now.

 

[Ned Ludd]

I saw Hornady's anvil several years ago and thought it looked like a really good idea, so I bought one. In practice, I found it much more difficult to use reproducibly than the caliper jaw by itself, so I simply went back to using the naked caliper jaw.

With the caliper jaw, a little wiggling and slight thumb pressure on the jaw wheel is necessary to get the base of the case aligned square with the jaw surface (i.e. to reach the "minimum" and correct measurement). It takes a little practice, but over time it is not a difficult skill to develop. My gut feeling tells me that using the anvil is situation where some may like it a lot, and some may not. I had been using the naked caliper jaw for years and was accustomed to doing it that way, so the anvil seemed foreign and difficult to use. For anyone that finds using the naked caliper jaw difficult, the anvil may be just the right thing.

 

[7887mm08]

I would think you are now doubling your chance of error.

 

[Bill Norris]

I saw Hornady's anvil several years ago and thought it looked like a really good idea, so I bought one. In practice, I found it much more difficult to use reproducibly than the caliper jaw by itself, so I simply went back to using the naked caliper jaw.

With the caliper jaw, a little wiggling and slight thumb pressure on the jaw wheel is necessary to get the base of the case aligned square with the jaw surface (i.e. to reach the "minimum" and correct measurement). It takes a little practice, but over time it is not a difficult skill to develop. My gut feeling tells me that using the anvil is situation where some may like it a lot, and some may not. I had been using the naked caliper jaw for years and was accustomed to doing it that way, so the anvil seemed foreign and difficult to use. For anyone that finds using the naked caliper jaw difficult, the anvil may be just the right thing.

Agree 100%. I got the short Hornady base as well but realized I could do a better job with what you described. The extra base seems like it would in fact create more room for error. But in general these numbers we are getting are just a guide and probably are not the actual measurement.

I would think you are now doubling your chance of error.

 

[Metal God]

Yep I pinch them down before tightening set screws , I’ll add that I don’t use the push wheel to do so but rather actually pinch the caliper jaws them selves closed . This helps prevent deflection/flex in the tool as I do so

 

[Ranger007]

SELLING - Caliper Bases - $22.00 Shipped

Updated - 12.31.2024 - Current time from purchase to received - 3-4 days. Ensures consistent and repeatable measurements during the bullet seating process. See forum comments, reviews and feedback. PM me for additional information. 6061 Aluminum - Hard Anodized Black. Use in conjunction with...

forum.accurateshooter.com

 

[Metal God]

But in general these numbers we are getting are just a guide and probably are not the actual measurement.

Mine are not , my comparator measures my GO gauge/s .010 shorter then they are .

 

[dgeesaman]

Yep I pinch them down before tightening set screws , I’ll add that I don’t use the push wheel to do so but rather actually pinch the caliper jaws them selves closed . This helps prevent deflection/flex in the tool as I do so

Exactly. Then under very gentle pressure I rotate the piece of brass about 1/4 turn to help it align.

I do not see more than .0005 variance when I follow my process consistently. Anvil or not. But I generally have the anvil on my calipers and it tends to stay there.

David

 

[RustyInBend]

I use the headspace and bullet comparators from Short Action Customs ... they're cut to much more precise angles and seat much better than the Hornady versions. With the SAC inserts, it just takes a little jiggle on the base and they lock right into place for a clean micrometer measurement. The headspace comparator inserts are amazingly solid since you buy them to precisely match the shoulder angle of your cases. Highly recommend this product ... but it ain't cheap.

 

[Tesoro]

You get what you pay for in tools!

 

[HandgunHTR]

SELLING - Caliper Bases - $22.00 Shipped

Updated - 12.31.2024 - Current time from purchase to received - 3-4 days. Ensures consistent and repeatable measurements during the bullet seating process. See forum comments, reviews and feedback. PM me for additional information. 6061 Aluminum - Hard Anodized Black. Use in conjunction with...

forum.accurateshooter.com

This is what I use.

 

[hk-93]

Tesoro
Thanks for posting this Idea. I have been using this idea for some time now and I find that I get better consistency in measurements. I will add that using a "base" with a hole that is larger than the primer gives you the assurance that an errant high or inconsistent primer doesn't interfere with your measurements like a flat anvil would. Although I know we always seat our primers perfectly. LOL

I would like to add another trick that I have been using. When measuring bullets for sorting purposes I use an insert on the opposite side one or two sizes smaller and seat the BT base into the hole and I find that it lines up very quickly and accurately. Since we are using this as a comparison from one bullet to another and not a true measurement of length it works very well for me. This given you are measuring BT bullets. Doesn't work so well on flat base bullets. I am also assuming that the BT profile is consistent. Just trying to eliminate as many variables as possible.

In case anyone is wondering the thumbscrews are from a computer chassis much handier than setscrews.