Ken's Barrel Break-In Method
Ken's barrel break-in method is issued after a new cut-rifled barrel or rebarrel at Double H Gunsmithing in Blanch, North Carolina. It is for new cut-rifled centerfire barrels. It requires disciplined shooting and cleaning. Done correctly, it helps the barrel settle, preserves accuracy, and keeps copper from establishing in the bore. Most of that work happens in the throat, where the bullet first engages the rifling.
Fire from a solid rest. This is not a casual plinking session.
Related work lives on our Rifle Builds and Rebarreling pages.
Equipment needed
- Carbon fiber cleaning rod
- Nylon brush (caliber-specific)
- Patch loop
- Cotton patches (caliber-specific)
- Bore guide
- Copper solvent
- Kroil penetrating oil or a general-purpose bore cleaning oil
- Flashlight
- Safety glasses, nitrile gloves, and other PPE
What “clean” means in this method
- Use a nylon brush only. Do not use bronze, brass, or stainless brushes.
- Apply copper solvent directly onto the nylon brush from the bottle (do not dip the brush into the solvent). Run at least 30 strokes.
- Patch with oil. Kroil is preferred; any quality gun oil is acceptable.
- Dry-patch the oil out until the patch comes out clean and dry.
- A patch loop may be used. Confirm copper is gone with a flashlight at the muzzle.
Phase 1
Shoot one, then clean. Repeat 3 to 5 times.
This is the most demanding and most important stage; it is where the throat is conditioned. Fire at paper or into a backstop, but hold the rifle firmly. After every cleaning, inspect the bore from the muzzle with a flashlight. Do not advance until copper is completely gone at the muzzle.
Phase 2
Shoot four, then clean. Repeat until the group settles.
The first shot off a clean barrel will usually print slightly off. Use the last three shots of each four-shot string to judge the group. Do not chase the scope during this period. Watch the group shift until it stabilizes. When it stops moving, break-in is complete and zeroing may be finished. That typically occurs within ten four-shot groups or fewer. Expect approximately 30 to 50 rounds on the rifle when break-in is complete.
Phase 3
Clean only when needed.
After break-in, use the same cleaning regimen only when accuracy falls off, when ammunition is changed, or when the rifle has sat uncleaned for more than two months.
Phase 4
Put the rifle to work.
The barrel is ready. Hunt, compete, or shoot groups. Leave the bore alone until Phase 3 applies.
Questions
Call or text 336-694-5739, or email [email protected], if you have questions about this method after a new barrel or rebarrel from our shop.