February 5, 2023 How to Craft a Modified Case to Measure Length to LandsOur friend Gavin Gear just released an excellent video that shows how to make a threaded Modified Case to use with the Hornady Lock N Load Overall Length Gauge. Gavin makes a Modified Case from start to finish. Gavin has some great tricks. To hold the cartridge case while threading, he uses a sizing tool. He then uses two drill bits to make the hole larger before threading the brass. He then locks the tailstock and leaves the threading tap IN place. Finally, he “gently pulls” on the quill to remove the brass from his lathe.
Hornady has chosen an unusual thread type for OAL Gauges. It is unlikely that you will be able to find the correct 5/16. – 36 RH HSS tap at your local hardware shop. This tap can be ordered from Amazon for $9.99.TECH TIPSModified Case Q&A — TECH TIPSWhy do you need a modified case?
A Modified Case is essential for any serious reloader. This is because it allows you to measure the length-to lands in your chamber with precision. With some practice and the Hornady OAL gauge, you should be able get repeatable length to land measurements within 0.015?. We usually do 4-5 measurements with OAL Gauge, and typically 3-4 will be “on-the-money”. NOTE: The pusher rod should be pressed gently and easily. Do not push too hard, or the bullet will be jammed into the lands. This can lead to inconsistent results.
Hornady offers a variety Modified Cases that can be purchased on Amazon or through retailers like Midsouth. Hornady offers modified cases for most standard cartridges. However, if you shoot a wildcat like the 6mm Dasher, or.284 Shehane you will need to make a custom modified case. Even if you shoot a standard cartridge like the.308 Win or.284 Shehane, you can get consistent measurements with a custom Modified Case. You’ll need to start with a case that has been fired in your rifle. This will ensure that you get the best fit for your chamber. You won’t have to expand the neck to allow for bullet clearance. Next, drill out the primer pocket. Tap the base of your case to match the threads in the Hornady OAL gauge tool. You will likely lose one of the cases you make, so make at least two modifications.
Similar Posts
