barrel crowning

[oldpowderhorn]

imformation on how to/ and tools needed/ and where to find them?

 

[musketman]

Use any large drill bit and a pair of locking pliers to hold the barrel in place (forget the holding)... :haha:

All kidding aside...
This will run you through the steps of crowning...
http://riflestocks.tripod.com/targetcrown.html

Gunsmithing tools can be had at: http://www.brownells.com/aspx/ns/home/default.aspx
They sell crowning tools...

 

[LRB]

Crowning a barrel is relatively simple. Square the the muzzle as best you can, does not have to be perfect. Use a ball file, much larger than the bore, I use a 3/4" for .45 and up through .54, in a hand crank drill or a variable speed power drill, and cut it in with a slow speed to where you want it. If you have a quality, sharp ball file, no clean up is necessary. A sphere self centers in a cone, or round hollow, and is theoretically more accurate than a lathe cut for this purpose. A good ball file will cost from 20.oo to 30.oo, but will last a half a lifetime if used properly and cared for, and will crown many barrels.

 

might want to consider squaring up the barrel and coning the muzzle. Helps in loading.

 

[Zonie]

Having just cut off my Bastard Guns barrel with a hack saw, I will give my method for the whole process as I did it on a swamped barrel.
1. Coat the surfaces of the barrel about where you want the cut with dykum (The blue stuff machinests use when scribing lines on metal parts). What, no dykum? No problem! Go to the Office Supply and buy a black Felt tip Permanent Marker.

2. Set the blade on a adjustable square for the depth (distance) of the cut from the end of the barrel and lock the blade. Resting the square on the muzzle, scribe the "cut off" lines on all 8 barrel flats.

3. Holding the barrel in a padded vise saw off the barrel just ABOVE the lines you scribed.

4. Rotate the barrel in the vise so the muzzle is pointing up.
5. Using a good file, file the sawn surfaces down to the scribed line. File from different directions across the muzzle and check the location of the surface from the lines often to produce a nice flat surface.
If you take your time and just bring the surface just to the scribed line it will be square with the bore.
While the barrel is still in the vise, use the file to lightly break the sharp corners where the new muzzle meets the flats and points of the octagon. The amount or size of this break is totally up to you.

6. Buy a 45 degree conical grinding wheel for an electric drill. They usually have a 1/4 inch shank. (I found a package of 8 different shaped wheels from China for about $3 at Ace.) Do NOT buy the electric drill unless you need it for something else. You will Not use it for this process.

7. Holding the barrel in your lap, insert the 45 degree cone on the grinding wheel into the barrel and using ONLY finger pressure rotate it back and forth about 1/2 turn in the bore. Inspect your progress to varify that the rough burrs are gone and it is beginning to champher the edge of the hole.
Keep up this process, rotating the barrel 1/4 turn about every 5-10 twists of the grinding wheel. Also rotate the grinding wheel about 1/4 turn in the opposite direction from the barrel rotation.
Keep this up until the new crown is slightly larger than the rifleing grooves.

My reason for not using any power tools and using the method above is any power tool can remove too much material too fast and they can grind/turn/file off center without you even knowing it. If the crown is not concentric (running true) with the bore, the gun will never shoot where it's pointed.

8. Using finger pressure only, sand the new chamferd crown using 320 wet/dry silicone carbide paper until it looks uniform.

9. Repeat using 600 wet/dry paper and it will polish to a mirror finish.

There are a lot of ways to do this task, but this one has worked well for me several times.

 

[LRB]

Zonie, how do you keep the 45 degree cone concentric while turning in the bore?

 

[Zonie]

The idea is if you place a cone into a hole it will seek the center of the hole every time.
If you keep the grinding wheel shank (the part that would go in the drill chuck) pointed close (within 5 or 10 degrees) to the direction the barrel is pointing, the cone of the wheel will self center with the bore. In other words, as long as you are using just finger pressure to turn and guide the wheel it will remove material evenly all around the bore.
I don't know if it was clear on my earlier post but you should be applying a moderate amount of pressure to keep the wheel grinding away the steel just don't over do it by applying too much axial pressure or you may accidently force it off center.

 

[LRB]

Apparently it works for you, but I would not trust it, especially with a rock tool. If I wanted a coned muzzle I would buy the tool from the guy in Texas, If I want a muzzle crowned I'll do it with a ball file. Thanks for answering.

 

[JOHN L. HINNANT]

Greetings All,

I do not want to come across as a know-it-all, but I do have some problems with some of the crowning procedures posted here. The same accuracy factors that apply to modern center fire rifles also apply to muzzle loading rifles. Crowning is one of those factors. The prerequiste for both rifle types is to square the muzzle. This best done in a 4 jaw chuck on a metal turning lathe. Centering the bore is mandatory. Centering on the flats or outside diameter is useless and wrong. The ball exits from the bore, not the flats.

I use a 60d center in the muzzle and supported by the tailstock live center. A dial indicator is set against the 60d center and indicated to 0.000" on center. The breech end of the barrel also centered on the back end of the lathe also.

After centering, the end of the muzzle is faced square to the muzzle with a lathe tool. A barrel muzzle can not be squared any better than this, and hand squaring with a file can not match this degree of accuracy.

This is the step in crowning. The next step will be described in the next post.

john L. Hinnant