INSTRUCTIONS Straight & Curved O.A.L. Gauges. Max. Cartridge Gauge or a Cartridge Headspace Gauge (Hornady makes an excellent one.) Anyone ever use one of Hornady's Lock n' Load OALgauges and Bullet Comparator? I bought one, went by the instructions and the length from the bullet Learn how Hornady's OALGauge can be used to increasing accuracy in your hand loads. There are a number of ways to adjust bullet depth, however I will show you how to accomplish this task by using the Hornady comparator and OALgauge. Hornady Manufacturing, Inc. Team Hornady; Dial Caliper and OALGauge not included. Product Resources. OALGaugesInstructions; Reloading. I went to SW over the wekend and picked up a HornadyOALgauge they did not have a Remington 300 RUM dummy round in stock so when I got home I was reading the instructions that came with it and they said to send 2 pcs of fired brass to them and they could tap and thread it to fit the OALgauge my Make Your Own Modified Case for HornadyO.A.L. Gauge. whlile you drill and tap them for use on the OAL it-yourself instructions mention to Find best value and selection for your Stoney Point OALgaugeinstructions and modified case for 223 Remington search on eBay. World's leading marketplace. Amazon.com : Hornady C1000 Lock-N-Load OAL Length Gauge (Straight) : Gunsmithing Tools And Accessories : Sports & Outdoors OalGauges & Modified Cases. 3 Items. Hornady 6.5 x 55 Mauser Lock-N-Load Modified Case Permanent Link to Product Page. headspace gauge and complete instructions.