Sinclair International Hex Style Bullet Comparator #1 22-30 Caliber

The Sinclair International Hex Style Bullet Comparator #1 is a precision reloading tool that lets you measure bullet seating depth the way match-grade ammunition builders do. Machined from stainless steel and featuring throated holes that replicate actual rifle throats, this comparator works with your digital calipers to give you repeatable, accurate measurements from the bullet's major diameter back to the case head. Whether you're fine-tuning seating depth for a hunting load or chasing consistency on the bench, this tool eliminates guesswork and helps you dial in performance that matters.

This particular model handles the most popular rifle calibers in the .22-to-.30 range, making it a go-to choice for reloaders working with common hunting and match cartridges. The hex-style design sits flat and stable during measurement—no clamping to your calipers, which keeps them free for other tasks. Sinclair has been refining this design for over two decades, and it shows in the precision of each throated hole.

If you're serious about ammunition consistency, seating depth is one of the few variables you can control shot-to-shot. This comparator gives you the precision to measure it accurately, then use those measurements to adjust your bullet seater with confidence. It's the kind of small tool that compounds into better accuracy over time.

Key Features

• Stainched stainless steel construction for durability and corrosion resistance
• Throated holes engineered to match actual rifle throat dimensions
• Works seamlessly with standard digital calipers
• Does not attach to calipers, leaving them free for other reloading tasks
• Precision measurement from bullet major diameter to case head
• Enables accurate seating depth adjustments for improved ammunition consistency

Specifications

Frequently Asked Questions

What calibers does the Sinclair #1 comparator work with?

This model is threaded for .224, 6mm, .257, 6.5mm (.264), .270, and .30 caliber bullets—covering the vast majority of centerfire hunting and match rifles in the popular mid-range category.

Do I need special calipers to use this comparator?

No. The Sinclair Hex Style Comparator works with any standard digital calipers you already own. It doesn't clamp or attach to them, so your calipers remain free for other reloading measurements throughout your session.

How is this different from other bullet comparators?

The throated holes are cut using actual throat reamers to replicate the geometry of a real rifle throat, giving you the most accurate representation of how your bullet seats in the chamber. This precision has been refined over more than 20 years of design and manufacturing.

What measurement does the comparator give me?

It allows you to measure the distance from the bullet's major diameter back to the case head, which translates directly to seating depth. You can then use that measurement to make precise adjustments to your bullet seater for load-to-load consistency.