I have three different bullet comparators in 22cal, all three measures the ogive at a different point on the bullet. The Sinclair is the best it repeats, and is made of stainless steel so it will not change in time. If seating the bullets deep it maybe a problem it has the largest hole of the three comparator I have . This comparator works great for me.

Hole sizing is incorrect on mine as well. And I'm not seeing an online way for tech support. Product is useless.

The hole in the comparator is that large the base of a bullet goes below the face of the comparator.

I had to give it a star rating but in reality it doesn't even qualify for the one star.

Advised to return it but International shipping is going to be more than the cost of the 3 comparator inserts.

I have the Hornady bullet comparator that I normally use. When my shooting partner and I noticed a .010 difference in our Hornady headspace comparator, I ordered the Sinclair bump gauge and the bullet comparator. The Sinclair tool is produced from quality steel and is well constructed.



My issue with the tool is that on Sierra MK and Berger Juggernauts, it slides all the way down almost to the base of the bullet. I can't get repeatable results with this tool, where I can with the Hornady tool which is only made of light aluminum. The Sinclair tool does not seem to be measuring from the ogive, but more from the bullet base. As another user reviewed, when used with Comparator body, it measure 1.1 inches, rather than 1.0 like the Hornady. Because of the inaccuracy and non-repeatable readings on the same bullet, I can't continue using this.

Excellent quality - much better than the competition - made of steel - much better that aluminum. Thanks Sinclair!

Simply does not work. When trying to measure SMK in 52, 69, and 77 gr, the comparator simply slides all the way over the bullet until it reaches the case.

I bought this comparator to use with the Sinclair XL Comparator body. It fits like a glove and gives accurate measurements from the ojive of the bullet to the base. Buy two of them and two bodies and you can also measure bearing surface of the bullet. I would definitely buy it again.

I was using this insert to sort 69 grain Sierra Match King bullets. The ogive on the bullet combined with the taper on the insert makes it hard to get repeatable measurements using a caliper. It's much too easy to cause the bullet to move further down into the insert while taking the measurement. The same thing happens with assembled rounds. For these bullets, the Hornady insert works better.

I have a bullet sorting stand and comparators on order, I hope that is more repeatable.

Also, I use a dial caliper. I can zero out the thousandth's but not the tenths of an inch. It would be nice if the comparator assembled to the insert would measure about 1.01 inches rather than 1.11 inches. It's easier to mentally subtract 1 inch from the measurement than 1.1 inches. If you use a digital caliper, it's not a problem.

Used with the Sinclair comparator body and a caliper to check OAL (base to ogive or datum point) on the bullet. Easy to use with repeatable results. Get two comparators with inserts and length sort the bearing surface area of bullets to help improve accuracy.

All the details in my rating for the 6mm comparator apply here too, but I've found a problem with the .204. To get optimum groups with my Cooper M21 20 TAC, some of my loads need to be seated very deep. The Sierra 32 gr MK and Hornady 45 gr SP achieve 0.25 MOA or better, when seated 0.100" off the lands. That's right, 1/10" jump! At this depth, this new comparator runs into the mouth of the case before it can come into contact with the bullet, so it's useless. And I'm not seating these bullets past their bearing surfaces. I'd like to see the geometry of this insert changed so that the max diameter of it's tapered hole would be 0.202". Right now I measure it at 0.211". In fact all of these new Sinclair inserts should limit their maximum taper diameters to (at most) the diameter of the bearing surface of bullet they are used for.

Measuring with a tapered comparator is much easier than with a 90 degree edge at the end of a straight hole. Using this insert with the Hornady LNL OAL tools yielded consistant readings on each test. No need to take multiple readings and find the average. A second reading to verify the first and your done. There is one difference though. Getting a reading is quickly done, but if you apply mild pressure and wait a bit you can watch the number go about .002 lower. It feels like your squeezing the air out from between the bullet and comparator surfaces. A tap on the side of the bullet's base is needed to release it from the insert. Rest assured, the insert left no marks on the bullets I measured. This review covers the 6mm insert used to measure 8 different bullets, 80 to 106 grains, by Berger, Sierra and Lapua.