How to use Hornady Comparator

[USMCM16A2]

Guys,



How does one translate the information one gains from the Hornady Comparator, and convert it to the bullet seating die. I understand that the calipers and the comparator will give one the length based on where the ogive is widest. But how does one set the bullet die based on this information. Thanks, USMCM16A2

[ocabj]

You use the bullet comparator in conjunction with the Hornady Overall Length Gauge. You use the Hornady OAL tool too find where that specific bullet hits the lands. Then measure that reading using the calipers and bullet comparator.

[USMCM16A2]

oc,



Thanks, but I need more specifics, so I put the completed round in the calipers, put the bullet in the comparator, the case head on the other end and get a reading off the calipers. How does this info translate over how to adjust the seating die?. Thanks,

[ocabj]

oc,



Thanks, but I need more specifics, so I put the completed round in the calipers, put the bullet in the comparator, the case head on the other end and get a reading off the calipers. How does this info translate over how to adjust the seating die?. Thanks,

That's exactly how you do it.

How do you adjust the die? Well, you set the die and measure the length. If the resulting round is too high, then adjust the seater stem down further and measure again. Setting your seater die by measuring the case head to ogive length is always going to be trial and error.

[Ahhnother8]

Setting your seater die by measuring the case head to ogive length is always going to be trial and error.

Not if you have a seater die with a micrometer. Well, not entirely true. Your first setting is a guess. Then just dial down however many thousandths you need with the micrometer. All other types are educated trial and error.

[ar15barrels]

Not if you have a seater die with a micrometer. Well, not entirely true. Your first setting is a guess. Then just dial down however many thousandths you need with the micrometer. All other types are educated trial and error.

I have made simple delrin discs with micrometer type markings for many of my Forester and RCBS dies.
They just thread on to top of the seating stem.
They look like a pizza cut into 31 pieces so I can easily turn the seating stem up or down a specific amount.

Only problem now is that I no longer have access to the CNC machine I used to make these on...

[ocabj]

Not if you have a seater die with a micrometer. Well, not entirely true. Your first setting is a guess. Then just dial down however many thousandths you need with the micrometer. All other types are educated trial and error.

Yes, you still need to do trial and error checking with micrometer seaters. The true beauty of the micrometer seater is being able to change the seating depth quickly, accurately, and repeatably, when you record the corresponding reference marks on the micrometer die for the desired seating depth (with that specific bullet).

[westcoastr]

I have made simple delrin discs with micrometer type markings for many of my Forester and RCBS dies.
They just thread on to top of the seating stem.
They look like a pizza cut into 31 pieces so I can easily turn the seating stem up or down a specific amount.

Only problem now is that I no longer have access to the CNC machine I used to make these on...

too bad, you should sell these!

a slight highjack here but does the straight Hornandy OAL gage have a solid inner rod that doesn't compress much when you put a force on it? i bought the curved version for the lever and auto guns and found out i don't need it. but the inner rod is very compressible, so it is difficult to take consistant readings as you have to put the exact same pressure when settting it and when using the caliper. the rod is solid steel rod wrapped in thin brass wire (it appears) and either the rod compresses or it bends in the tube (as there is some play between it and the ID on the gage) or both, which makes it hard to get a consistent measurement