December 24th, 2024

Craft Your Own Length-to-Lands Measuring System

case OAL gauge home made

Make Your Own Length-to-Lands Gauge to Check Bullet Position
Here’s a tip we feature every year or so, because it is something that costs nothing, yet can be very useful in the reloading process. With a simple, easy modification to a fired case, you can determine the length to lands in your rifle barrel. As long as you set the tension right, the measurements should be repeatable, and you’ve just saved yourself $47.98 — the combined cost of a Hornady C-1000 commercial OAL gauge ($41.99) and Modified Case ($5.99).

To achieve best accuracy with a rifle, you must control bullet seating depth very precisely, so all bullets end up in the same place relative to the entrance of the lands, every time. There may be multiple cartridge OALs which prove accurate. However, with each, you first need to determine a “zero” point — a reliable, and repeatable OAL where the bullet is “just touching” the lands.

There are tools, such as the Hornady (formerly Stoney Point) OAL Gauge, that will help you find a seating OAL just touching the lands. However, the tool requires that you use a special modified case for each cartridge you shoot. And, while we find that the Hornady OAL Gauge is repeatable, it does take some practice to get in right.

Make Your Own Length-to-Lands Gauge with a Dremel
Here’s an inexpensive alternative to the Hornady OAL tool — a slotted case. Forum member Andris Silins explais how to create a slotted case to measure length to the lands in your rifle:

“Here’s what I did to find length to lands for seating my bullets. I made four cuts into the neck of fire-formed brass. Then I pressed the bullet in lightly and chambered the entire gauge. As the cartridge chambers, the bullet slides back into the case to give you length to lands. It took less than five minutes to get it cut and working. A little light oil in the barrel just past the chamber helps ensure the bullet does not get stuck in the lands. It works great and is very accurate.

How to Adjust Tension — Length and Number of Neck Cuts
I made the cuts using a Dremel with a cut-off wheel. You can adjust tension two ways. First, you can make the cuts longer or shorter. Longer cuts = less tension. If you used only three cuts instead of four you would get more tension. The trick is to be gentle when you open and close the bolt. If you ram the bolt closed you may wedge the bullet into the lands. When you open the bolt it helps to keep a finger or two near by to guide the case out straight because the ejector wants to push it sideways.”

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