Pro Tip - USAMU Sgt. Joe Hein on The Cold Bore Shot
When discussing cold bore shots it’s important to differentiate between a clean and a fouled bore. A clean bore is one that has been cleaned using your preferred cleaning method. A fouled bore is one that already has shots fired through it.
Before we start our test there are a few things we are going to need. A bench, you’ll also need a rifle rest, a rear sandbag, the ammunition you intend to use on the range, and a log book to tally your shots.
To begin I have a target at 100 yards. I’ll fire my first shot and plot it in my logbook. This is my cold bore shot. I’ll follow up with four more shots plotting each of these. You will see a group form.
After you finish head down range and view the target. Referencing my logbook I can tell this is my cold bore shot, there is a distinct difference to my follow-on shots to my cold bore shot.
I’m going to measure on the horizontal and vertical plane from the center of this group to the center of my cold bore shot. That will give me the offset. This test was performed at 100 yards, if I move this target to 200 yards the offset will double. This test was done for a clean bore.
If I want to test for a fouled bore, I need to give the barrel the opportunity to cool, and come back 24 hours later and perform the fouled bore test.
This group is slightly tighter than our previous test. Generally a fouled bore is more consistent than a clean bore. Even though my cold bore shot is slightly outside of the group it is still more consistent than clean bore.
I’m going to take this knowledge and apply to a shot at 300 yards. A cold bore shot can be compensated for. Use the techniques I’ve shown you today, and apply them to your rifle, and you’ll be ready for opening day. Until next time stay Army Strong.