Making Modified Cases, SEB Rest Upgrades, ChargeMaster Tuning

Erik Cortina is one of the nation’s top F-Class shooters. A member of Team Lapua-Brux-Borden, Erik has been a top performer at National and World F-Class Championships. Erik is also a very smart guy and a skilled toolsmith who has upgraded his shooting equipment in interesting ways. Today we feature three “How-To” videos from Erik. These show how to upgrade a SEB Coaxial Rest, how to improve the performance of an RCBS Chargemaster, and how to create your own Modified Case for measuring length to lands. Watch and learn…

1. How to Make a Modified Case for the Hornady OAL Tool

In this video, Forum member Erik Cortina shows how to create a custom modified case for use with the Hornady Lock-N-Load Overall Length Gauge (formerly the Stoney Point Tool). While Hornady sells modified cases for many standard cartridges, if you shoot a wildcat such as the 6mm Dasher or .284 Shehane, you’ll need to create a custom modified case. And even if you shoot a standard cartridge such as the .308 Win, you can get more consistent measurements if you make a custom modified case from a piece of brass fired in your chamber.

MORE INFORMATION: Want to learn more? We published a much longer story in which Erik explains in greater detail how to made the Modified Case. That article illustrates the 5/16″ – 36 RH HSS Tap required and shows how to set up the lathe to drill and tap your case. If you are serious about making your own Modified Cases, you should Read the Full Article.

2. How to Upgrade your SEB Co-Axial Joystick Rest

Joystick (coaxial) rests are used by top shooters in benchrest and F-Open disciplines. With coaxial rests, you can adjust both vertical and horizontal aim instantly in one fluid movement — there are no mariner wheels to spin or knobs to turn. Just gently stir the joystick to move up, down, or sideways. Erik Cortina explains: “If you want to get into F-Class (Open) and want to win, you should get a SEB rest. SEB makes an excellent product, but the one thing we upgrade automatically … is adding the F-Class feet. These have a bigger footprint and a spike on the bottom [so you can] dig the feet into the ground and make your rest a lot more stable.” In this video Erik installs a set of Blake Machine Co. F-Class feet. These feature a set-screw, so they are easy to attach and then remove for travel (no Loctite!). “Simple yet effective” declares Erik.

In the second half of the video (starting at 5:30), Erik installs a Dan Bramley Joystick Holder. This features two clamp-on cradles that hold the joystick crosswise below the top (see photo). This handy accessory ensures your handle always remains with the rest (and doesn’t get left at home when you travel to a big match). This joystick holder has been popular with competitors. Erik says, “The Bramley Joystick holder is $60.00 — money well spent.” To order, email Dan at dbramley [at] yahoo.com.

3. How to Make the RCBS ChargeMaster 1500 Work Better

Erik Cortina has been fiddling around with his RCBS ChargeMaster and he discovered something interesting. Through a series of tests he determined that the ChargeMaster dispensed slightly more precise charges when he trickled the last few 10ths of a grain on to the RCBS pan. Erik wasn’t expecting this result, but he confirmed there may be a slight benefit to this trickling method (as opposed to allowing the ChargeMaster to dispense the full charge). You can see Erik’s test procedure in this video:

We should note that Erik’s preferred method of weighing powder is to first dispense a slightly lower charge with the RCBS, transfer the pan to a laboratory-class Sartorius magnetic force restoration scale, then trickle up with his Omega (Dandy Products) Powder Trickler. However, if you don’t have a $800+ laboratory-grade scale, you might just try trickling on to the ChargeMaster pan.

MORE INFORMATION: We have published a more lengthy Bulletin Article that covers Erik’s Chargemaster Performance Findings in greater detail. That article has more photos plus a clever, bonus “Beep Defeat Tip”. If you own a Chargemaster, we recommend you READ the Full Article.