11 Degree Target Crown
Without a doubt, the crown of a rifle is essential for accuracy. A crown that does not run true to the bore can not only destabilize the projectile as it leaves the barrel, but also causes erratic behavior of the pressurized gases as they escape the bore. Remembering that rifle bore is never exactly centered in the barrel, this isn’t a cut you can index off the exterior of the barrel. While a competent smith can dial in the bore on his lathe using a four jaw chuck and a spider on the other end of his headstock, this cannot be accomplished if the barrel is too short. So how do you get a target quality crown without a lathe or, on a shorter barrel? Use a piloted crown tool.
In addition to a saw, vise, file, tape measure and marker, that we needed to complete this project; we ordered the following items from Brownells:
We began be ensuring our rifle, in this case a Remington 700 308 built on a new action with a Holland recoil lug and Shilen select #7 contour match grade barrel, was unloaded. The instructions that were provided, state that rifles do not need to be disassembled. Since our barrel action was already out of it stock, we decided to remove the bolt as well.
Our barrel was originally 25″ long, we decided a 20″ barrel would be more useful.
We began by marking our barrel where we will make the cut.
A barrel can be cut with a hacksaw or power saw. We used a portable, cut-off band saw; making sure we cut on the waste side of the mark that we made earlier. A little bit of Do-Drill oil was used to keep the blade lubricated for the cut.
This is how the barrel came off of our band saw. Pretty rough; no worries though.
We secure our barrel vertically in a vise with a set of blocks. A large file, coated in chalk to prevent fouling, is used to begin to true the face. We took our time and made sure our cuts are perpendicular.
The file does an excellent job removing the saw marks.
Placing a strip of 220-grit abrasive cloth against the file, we remove the file marks from the barrel.
The sawing, filing and sanding of the muzzle creates a burr in the bore that needs to be removed prior to using the refacing tool. To break the burr, we drop a pull-through patch puller down the bore and run a tight fitting patch up. This does an excellent job of removing it and clearing the way for the refacing tool pilot.
This is the Dave Manson Precision Reamers muzzle crown refacing kit. Available from Brownells in either a 2 (22. and .30 cal) or 5-pilot configuration (.22, 6mm. 7mm, .30 and .338 caliber). The kit includes 0 and 11 degree facing cutters, a de-burring cutter, 5 pilots, a brush, pilot wrench, screw driver and spring loaded drive tool. Unlike other facing tools that use a pilot rotating in the bore, this one uses fixed expanding pilots that prevent premature wear.
We insert the .30 caliber pilot into the bore.
Using the provided pilot wrench, we tighten the pilot into place.
We start with the 0 degree cutter. We apply a little bit of Do-Drill oil to the face of the muzzle prior to cutting.
We secure the drive tool over the cutter as shown. The pilot and body of the drive tool remain stationary. The handle is set in bearings allowing the handle to remain still. The handle is also spring loaded, so the operator does not need to worry about how much pressure is applied. This is a very user- friendly tool.
As we cut, we frequently take the time to remove the shavings from the tool with the brush that’s included.
After a few turns with the 0 degree cutter, we can see that we were actually pretty close to where we needed to be. Note the freshly cut shiny surfaces (left) next to the filed surfaces (right) that still need to be cut.
Note how the file marks disappear as the cutter trues the muzzle. Once the remaining file marks are cut (top right edge), the entire surface will be perpendicular to the bore.
The tool makes quick work of truing the muzzle perpendicular to the bore.
Next, we apply a little bit of Do-Drill oil and begin cutting with our 11 degree cutter. We clean the surface of the chips often. Stainless steel can spall if the chips become trapped, providing an unfinished look. Once we reach the proper depth of cut, we gently run the tool to give the crown a finished look.
With the desired crown now cut with the 11 degree cutter, we use the de-burring tool on the pilot to break the outside edge of the barrel. Once completed, we loosen the pilot and use our hands to remove it.
The finished 11 degree target crown. The entire process took around an hour and is quite rewarding. Since this was a stainless steel barrel, we don’t need to refinish it. Had this been a blued barrel, we would have used a little bit of cold blue on it.
This was a fun and rewarding project. Prior to reassembly, we took the time to thoroughly clean off any metal shavings from our barreled action. Now we can’t wait to shoot it!
Start up costs for the kit will set you back $360 (2-pilot version). While this may seem expensive, keep in mind how much a quality crown job will cost. In a few barrels the tools will pay for themselves, plus you’ll have the pride in workmanship of having done it yourself.
For quality gunsmith tools and accessories that are backed by a 100% lifetime satisfaction guarantee, make sure you check out Brownells.