[g1_dropcap]T[/g1_dropcap]He following is an excerpt of our online training lesson, minus the accompanying video.
Coldbore Variations, Online Training Lesson
Three variations can show up as a cold bore shift when starting out with your precision rifle.
- Clean ColdBore
- Fouled Coldbore
- Cold Body Cold Mind
Clean Cold Bore is when the rifle has been cleaned, and it needs to replace the good copper that was removed.
We have good copper in the barrel that fills in some imperfections. Consider the example of the cast iron frying pan, where it has to be re-seasoned. A cleaned cold bore is often dependent on how aggressive the shooter was cleaning the rifle.
This is caused by a physical change inside the bore.
Fouled Cold Bore
A fouled cold bore is not a natural condition. If the rifle has been fouled and it still exhibits a cold bore shift, first look at the Cold Body Cold Mind definition. Next, consider checking the torque settings of the rifle. We have seen problems in both action screw torque as well as the barrel receiver mating.
In this case, there may be stress in the system causing it shift. Most of the time you will notice the group walk a bit. If you have a perfect, cold bore shift with the other four shots grouping together, again see the Cold Body. It’s not a natural state.
After checking the system, if the shift remains consider replacing the barrel. You will have to monitor and record this variation for future adjustment.
Cold Body – Cold Mind
This is essentially a first-round flinch. The body is not prepared for the recoil, and the brain moves to protect itself from the recoil and or sound of the gunshot.
We have tested this found with dry practice prior you can inoculate yourself from this first round flinch. You can also check this issue by bringing a second rifle to the range. Fire at least ten shots with the first rifle then move to the precision rifle with a perceived cold bore shift. More times than not, the shift will go away.
Cold Body Cold Mind is subconscious; it’s tough to see you are doing it. Thus a series of tests should be conducted.
Suppressors can also have a first round pop which will mimic a cold bore shift. Same basic principle but found inside the suppressor. If the suppressor is well used, it’s a design problem. If the suppressor is new, try shooting more and fouling it. I had a Gemtech Sandstorm with a first round pop, and after 500 rounds of carbon build it, the shift disappeared.
Track your rifle
Test and record your shifts, measure the distance and work to remove it. I recommend a paper target that travels with you in order to track the differences and changes. Since you can really only test it once, carry it with you.