New Reloader Question - Bullet Comparator

[MikeRu]

Not sure that's ideal, depending on what you're trying to accomplish. I'd want the tool to measure as close to the actual ogive (the point in the bullet that first contacts the lands) as possible in order to minimize reading any ogive to nose variation in the bullets.

Yes but Curt is called the “mayor” for good reason!
Mayor of xxx but not gonna go there.

 

[Tesoro]

That’s going to be solvable, but best if you could have someone there to see the issue.

Possible issues:

Avoid the flat Hornady base, it causes issues —just use the naked caliper blade and the correct comparator.

Hold the blades closed against the empty comparator with your fingers, and then tighten the set screw.

Spin or wiggle the case/bullet until it’s base is flush on the caliper blade, giving the smallest length reading.

If there is play or wobble in your calipers then check the tensioner screws that hold the arms in alignment. The screws should be just snug and it should slide with light pressure.

One higher $ option is to use the Hoover Accuracy One bullet trimmer housing as a mount for your calipers. They slide back and forth in the mount, much less of an issue with thumb pressure as a variable.

Mitutoyo calipers are a nice upgrade. More $…

I have used the flat base without issues? I also bevel the comparator bullet hole so It seats better and that factory edge dosen't scribe onto the jacket. I seat my primers below flush.

OP needs to check that after attaching the comparator that the bottom jaw lines up with the center of the bullet hole when closed. I have one where it only aligns one way with the screw knob to the rear.

 

[Ccrider]

I have been using this for years. A well kept secret: https://bullettipping.com/products/seating-depth-comparator/

 

[old_heli_logger]

Make sure all of your primers are below flush.
Good luck

 

[Clay Callan]

Updated 4/10/2026:

I bought the Derraco bullet comparator set off of amazon and now I get consistent measuresments. The hornady comparator must be damaged or the wrong size/mislabeled. Solved.