I never kept records in individual rifles till I became a Small Arms Test Director at Aberdeen Proving Ground and I went from 0 to 100 MPH overnight as we had to log everything that happened during test to include rounds fired, malfunctions noted, the round number it occurred on and classified per code (FTF failure to fire, FX fail to extract, FFD Fail to feed etc etc). Magazines were also numbered so when a stoppage occurred we had to download mag to determine the exact round in the mag that the problem occurred with. Then all testing stopped while I wrote up exactly what happened, when, mag number etc etc etc and a report had to be written up and sent to the agency paying for the testing. Once all my notes were complete the test continued.
Mag number recording is critical because if the same mag has a stoppage in a different weapon or more the mag is examined very closely and retired from service and the stoppage is charged to the mag and removed from the rifle.
Now on my personal rifles I got to Walmart and get little notebooks about 2 1/2" X 3 1/2" that have hard covers and are stitched so the pages don't get ratty and fall out. I drill about a 3/16 hole in top of book and loop about a 14" length of mason's twine (nylon) through it. On the outside is the rifle number/caliber. On the inside (on a new rifle) I record firing pin energy, erosion gage readings, rounds fired by day and any other thing I think of to write down. Every 500 rounds I run the erosion gage in the bore and record how far forward it has moved. Once the barrel is removed I make a notation of when, chamber reamer used, all data about the barrel (twist/manufacturer etc) and that way I know the rounds on the barrel and the rounds on the action. Each book is lock looped around the barrel so I have the data for each rifle all the time and can make notes on the line of anything I want to remember.
At the beginning of the shooting season I check firing pin energy.
Before going to Aberdeen I never kept any records but now I do. The little books run like 77 cents each. Drilling the holes is might best be accomplished with a piece of steel rod drilled out to make it hollow and sharpened on one end and put in a drill so you are cutting each page and not drilling through. I was lucky in that I was at a print shop owned by friends and they were retiring a hole maker and were going to toss it. I asked for it and they gave it to me. Been using it 20 years I guess.
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