Crowning?

[longcruise]

I appreciate both points of view expressed on this topic!

My first thought was to simple cut the barrel off about a 1/4 inch and re crown it. Am not daunted on that score since having done it several times in the past with hand tools.

OTOH, it may be a good opportunity to try a round ball in a hand drill or brace. Worst thing that can happen is I'm no worse off than before and time to start cuttin and crownin.

My intuition says that KanawhaRanger is on the right track but at the same time trying the ball is a no lose situation. I know one guy whom I would trust to work on it in his lathe and he is off traveling for the summer.

I'm going to try this as soon as there is an opportunity. In my tool box is a ceramic round ball with a shank on it. It that the one?

 

[Tumblernotch]

I don't know about the ceramic balls, but a lead ball several calibers bigger than your bore will work. Actually any kind of material should work as long as it's hard enough. You wrap the ball in a patch and dip it in valve grinding compound and push it into the muzzle. Turn it back and forth 4 or 5 times. Turn the barrel 1/8th of a turn and repeat. You can use the flats for your guide. I polished a crown this way just this morning. First, I used a tool I made from a piece of wood coned at an angle. Using double backed tape, I stuck 320 grit sand paper to it. There is a 1/4 inch all-thread rod that goes though the wood cone lengthwise about 8 inches long. Two brass bushings the size of the bore are threaded to the rod to act as guides that keep the cone square with the barrel. I use the same technique as with the lead ball. If the crown is real rough you could use a coarser sandpaper or emery cloth and work down to a finer grit. You'll also need to put a nut on the end of the rod above the cone to keep the rod from falling through into the barrel. It does a pretty neat job.

The ball I used for my .50 was a .570. All you need if you do it that way is something just a little larger than your bore. The bigger you go, the bigger the radius.

 

[Kentuckywindage]

well after shooting the rifle at 200 yards today, im going to find a grinding ball and do it by hand. I dont want to screw up what i've got started! Shot beautiful, Just a plain to start the conical into the bore with it being sharp the way it is.

 

[dbutch]

On a larger bore, you can crown a muzzle by simply pushing a small piece of sandpaper or emery cloth into muzzle with your thumb and turning. I did a .54 this way, and it turned out great. Just get a small square, lay it on the muzzle like a patch, and push in the center with thumb. Then turn the barrel and your thumb back and forth. You dont want the sandpaper to actually enter the bore, it should stay on the muzzle, just the middle should be depressed to cut the crown. After it is cut, finish with progressively finer grit to get a smooth finish.

roklok Just finished doing a 58 cal gm dropin...found the barrels happy load--ball-patch..coned and finished off the factory crown with 1500 wet and dry ..thumb tool.
Love the ease of loading...Dan

 

[longcruise]

KanawhaRanger

You are pretty much describing the method I use to crown muzzles and give them a slight cone (not like the deep cones that allow thumb starting of the ball. I described that process here;

Barrel conditioning

I don't think my cones are going to straighten the offset crown though. It seems like it might just follow the existing crooked crown.

OTOH, maybe if I start with the most shallow cone and take the entire muzzle from the outer lip of the crown down to an equal point that is deeper than the existing offset crown, it could be a new beginning.

 

[Tumblernotch]

:rotf: Oh brother! What a small world! The coning tool I made is patterned off the one you describe in your Barrel Conditioning page! The only difference is instead of using the nuts as guides to keep the cone in line with the bore, I turned 2 brass bore fitting bushings that thread onto the rod. Using this method, I can turn bushings for different calibers and use the same tool. It worked real well. I used a round ball in a patch with grinding compound to polish it up.

What you're saying about going with the shallow cone and working down may be the only way to get it even. It should work. Let us know how it goes.

 

[longcruise]

Oh brother! What a small world! The coning tool I made is patterned off the one you describe in your Barrel Conditioning page

:haha: That's hilarious. I always wondered if anyone ever bothered to look at it.

It occurs to me that I'm going to leave the crown untouched for now and do test shooting with the barrel as is and then with a new crown (getting there with whatever method will work) just to see if there is any improvement.

I like the round ball in a patch for polishing idea. Can you give us an idea of how you created those bore bushings? Pitchers would be nice!

 

[Kentuckywindage]

well boys i was cleaning up the shop and found the perfect tool to crown my barrel! I found an old valve from a 1972 BMW! I make sure it was clean and then rubbed some Flitz polishing compound on it to keep things lubed and then i just went about it by hand. After i got it shaped i used some 220 grit sand paper, slid it up the valve stem and then wrapped it around the head of the valve and went at it again. I followed up with 400 grit sand paper at well.

Came out beautiful! Its just enough to allow the conical to slip right in and not give me any fits.

I decided to give the bore a scrubbing as well and used some O and OOOO steelwool lubed with Flitz and gave it 100 strokes of each grade SW.

I'll work on pictures as soon as i get this place cleaned up.

 

[Tumblernotch]

I just happened to Google "crowning tools" and the page with the tool and pictures showed up. Didn't say who did it or what. It was about the same idea I had for making one but you made the cone out of wood and I figgered that would be easier and probably better than turning one out some kind of metal.

I figured I would need a bushing to keep the cone lined up and your idea of using the nuts jammed on the rod would work just fine for my .50 and that's what I planned on using for this job. Then I got to thinkin', what if I want to crown one of my .40's or something else that those nuts wouldn't fit. I had some 1/2" brass stud bolts here that I turn jags from, so all I had to do was clean them up and thread them for a 1/4" all thread rod. One would be enough, so I figured two would be better. I just thread them onto the rod a few inches apart and they keep things lined up. For any other caliber all you would have to do is turn a piece of brass down to where it will fit fairly snug and thread it to fit the rod. Heck, a man could make them out of wood if he wanted to. Here soon, I'm going to make some for the .40 as well as some other calibers.

I still haven't had the chance to see if this job improved my barrel any. I had a little ding in my crown and I believe it was having some effect on my shots. It wasn't really deep enough to start with and I think my shortstarter may have caused the problem.

 

[Tumblernotch]

Well, now there's another good idea. Be sure to send the pics!
:thumbsup:

 

[Kentuckywindage]

Ok i got the pics. Not the best but you can see it. I didnt go crazy and give it a deep dish type of coning. This barrel mainly will shot conicals and some round balls for fun or simply for small game.

I shot it today at 100 yards and came away with a 2" 5 shot group. My first 3 shots were touching and the next to waddled over to the right and opened the group.

 

[Tumblernotch]

That's a pretty good group. Anything could cause a flyer. Apparently your crowning job didn't hurt anything. The crown on my chunk gun barrel may be just a hair deeper than yours. You don't need too much. That looks like a good job.

I might try mine out some time this weekend. I need to get it ready for a shoot in July.

 

[ozrkreb]

"My intuition says that KanawhaRanger is on the right track but at the same time trying the ball is a no lose situation."

Actually, basic geometry supports Wick's explanation.

Az

 

[longcruise]

I fully respect both of their opinions on this matter. I was going to go at it with a ball right now but decided to hold off till the gun is ready to shoot. Then I'll shoot with the factory crown before doing anything else.

I have also considerd making one of my shallow crown tools and mounting it on a 15 or 20 inch all thread with three guides attached along its length. One at the base of the cone, one centered and one at the end. Idea being to apply light pressure with a course paper until the factory crown is even with the square of the muzzle.

 

[JOHN L. HINNANT]

Good Evening All,

It has been a long time since my last post on the ML Forum, but thought this subject would be an interesting one to comment on.

I have been building and shooting muzzle loading rifles for 57 years and have some very strong opinions based on those years of experience.

I must respectfully disagree with Wick Ellerbe's statement that the muzzle does not have to be square to obtain a good crown. Birddog6 did a good job of illustrating the problem trying to crown a muzzle that is not square.

A properly squared muzzle with a concentric crown is absolutely essential to promoting the best accuracy from a muzzle loading rifle or a center-fire rifle. Of course, each person must determine their personal standard of acceptable accuracy.

As far as I am personally concerned, the best and most accurate way to square and crown the the muzzle of ANY rifle barrel is to use a lathe eqipped with an independent 4-jaw chuck. Even then certain protocols must followed.

Not only must the muzzle be centered in the chuck, but the breech must be centered. In my shop, a series of alumina collars are used. The O.D. is turned to fit snugly inside the spindle wth THE I.D. drilled then bored to closely fit around the corners of the barrel. These collars support and center the breech of the barrel at the back end of the lathe headstock spindle.

Without this centering, the breech will have a great deal of "run-out" even through the muzzle might be be perfectly centered in the chuck. This means the length of the barrel is not aligned to the center of the axis of the center of the lathe. The end result is that the muzzle wil not be perfectly squared after"facing".

When centering the muzzle prior to "facing", it is important to center the bore, not the flats of the barrel. A 60 degree angle centering bar is inserted into the muzzle. The opposite end of the centering bar is drill with a 60 degree combination center drill and is supported by a "dead center" in the the tail stock.

A dial indicator is set up to touch the the centering bar as close to the muzzle as possible. With the dial indicator, the bore can then be centered to a bare "wiggle" of the indicator needle.

At this point, the old crown is removed in a standard lathe facing operation. When all traces of the old crown are removed, the bore is centered a second time. Some "run-out" alwaysshows back up, because the first centering is indicated in on a faulty crown.

After the muzzle has been properly squared, the lathe compound is swiveled to 20 degrees. A small boring bar is used to turn a 20 degree crown in the muzzle bore. The crown is cut just deep enough to remove the sharp edges of the the botton of the rifling grooves.

It is very important to note that turning the crown in this manner absolutely dictates that the bore be perfectly centered to no more than 0.0005" run-out on the dial indicator. Otherwise, the crown will not be centered with the bore.

A brass lap with a 20\5 degree angle coated is used just briefly to to remove the sharp edge left by the boring tool.

All of this may seem like a lot of work, But I can square and crown a barrel in much less time than it took to explain and detail my method.

Is all of this work really worth the time and effort/ I can only quote the late Colonel Townsend Whelen, "Only accurate rifles are interesting" and "The proof of the pudding is in the shooting".

I have re-squared and re-crowned dozens if not a few hundred barrels of both center-fire and muzzle loading type over the years, usually after the owner has attempted to hand square and crown the muzzle. Every one of them has showed very significant improvement in the accuracy department.

I respect the opinions of all others on this subject, but there is no way a human being can hand square and hand crown a barrel as accurately as a good machinist can do the same job in a lathe.

For me the difference between hand crowning and my method is being satisfied to hit a coffee cup saucer at 50 yards or nailing a fifty cent piece at the same range shot after shot.

With the years of personal experience behind me, it is not a debatable subject.

I remain with all respect,

John L. Hinnant

"God and Texas"