Problem with Coned barrel

[mazo kid]

Kent, I am at a loss to explain the lack of a group also. I have several rifles that I have coned and all are great shooters. What I don't understand (and please correct me if I am off base), is, as I said, the lack of a group. If the cone is somewhat off, wouldn't that throw ALL the balls to the same impact area, as opposed to a scattering? A crown that is "off" will do this also but will throw the balls to the same point of impact, even if it is not the not the POA.

 

[SR James]

Beats me Kid. I shot five shot groups for most of the combos I tried. Of the five, two might be within a couple of inches of one another, the rest scattered over 6-8". Now that I think of it, there was one consistency: all shots were either centered or left of center relative to aim point. In other words, if you drew a vertical line through the bullseye, all shots were either more or less center or to the left of the line. None were right of the line. So it appears to shoot to the left of center. Vertical dispersion was random. The shots were randomly scattered within the left hemisphere of the target.

 

[jethro224]

Gusty winds the day you shot? :idunno:

 

[paulvallandigham]

Kent: What do the spent patches tell you? If the patching is too thick, or too thin, that can cause flyers. Same with different lubes. Thin lubes don't always work best with all barrels.

My brother tested different sized RBs in his .45, starting with .440", then .445" , then .451", then 454" and then .457". The bore diameter is .451"

Altho he had to hammer the oversized balls into the muzzle, he initially got smaller groups. But, as he tested the over sized balls further, they began to spray all over. I think he is now back to using a .445" ball in the gun. Along the way, he changed patch thicknesses, and tried a number of different lubes. Its been a year of tests, so I am not sure now if he is back to using the original lube, and patch material, or if one or both have changed.

He also has 3 or 4 .40 cal rifles, and each gun has proven to like its own loading components.

Looking at that picture of the inside of the muzzle, it appears that the coning only goes into the barrel about 1/4". Normally, I would expect the cone to be 1"-2" in length. At the 2-3 o'clock side of the picture, it appears that part of a land is not coned. If the cone is uneven, that can be your problem, and it should show up on your spent patches. Cleaning up the cone, by having it redone would seem to be the easiest and cheapest way to restore this gun's accuracy. :hmm:

 

That's a short taper cone, and doesn't look like a guide was used, and looks to only be about a 1/4"deep. It should be closer to 1 1/2 or two inches, and a very gentle taper. Instead of cutting it, I would consider getting a Joe Woods coning tool or borrow one for the .40, and recut to cone correctly. The crown itself looks to be very small, It may be a lot easier than cutting the barrel, and stock work. I think Keith Lisle cones all of his guns, and the fifty of his I have shoots 1" at a hundred yards. I've used Joe's tools to cone more than five guns with no degrade in accuracy. Looks like yours was done with a rat tail file, by hand with no guide. I don't have the .40, or I'd offer to loan out to you, Mine are all larger calibers. Cut the barrel, or recut the cone, or replace the barrel, seems like your three choices. Good luck!

Bill

 

[ApprenticeBuilder]

Though I am not a fan of coned barrels,

From the pictures you could either do as you initially thought, cut the barrel a tad and go on your merry way without changing the overall asthetics by much,

Or do as Bill suggests and cone it correctly which would clean up the mess that you aquired.

Being the person that I am I would probably just cut it back and re-crown it, problem solved.

 

[jtmattison]

I have coned a few of mine with no negative affect on accuracy.

Maybe yours is not symmetrical.

HD

 

[Bill Hall]

I thought about the muzzle being out of square, but I can see it has those typical GM factory tool marks, so I assume it's good and square.

That crown and cone doesn't look that bad to me. Of course it has to be exact, so who knows. Still, I just can't help thinking the problem is being caused by some unknown vibration.

I have a crazy idea. I've never tried this, or even heard of it before, but I wonder what would happen if you wrapped duct tape all the way down the barrel. Get that barrel really tight and snug. Kind of a pain in the you-know-what to do, and you would need to add a layer of something between the tape and gun (leg of panty hose?) so there would be no tape residue left, but that's the only troubleshooting approach I can think of. Wrap up the barrel, see how it shoots, if it makes a clear difference, you would then know which direction to go. And, if it helped, you could quit thinking about doing surgery on the crown. Just throwing it out there. Bill

 

[ApprenticeBuilder]

Its funny really,

but if you look at that picture he posted, really close, I mean enlarge it big, (great picture by the way, very crisp) you can see that the cone is very inconsistant.

In my experience the barrel carries the stock wood, the wood does not support the barrel.

With this in mind, you could remove the barrel pins from the forearm and have no loss in accuracy at all provided the tang screw is secure.

As was mentioned earlier, a correct cone extends approx. 1 1/2" to 2" into the muzzle. Looking at the muzzle pictured, at best it looks like its only a 1/4" or and I would speculate that it was accomplished by a hack.

 

[Fred_Dwyer]

Is that bedding compound oozing out of the inlet around the barrel?
If that is, I'd remove that before I cut off metal; bedding compound can be replaced if desired, metal? not so much.
The inconsistencies in the coning are at least consistent from land to land, as if as the rifling was cut; metal was raised on one side of the lands.

If it is bedded I'd get it free-floating before I started doing something irreversible.

 

[ApprenticeBuilder]

I just don't see the consistancy in the cone job, I see uneveness in the lands that are visible.

But then again I don't see any bedding compound ooozing out from under the nose cap though either, I see grime.

If there is in fact bedding compound at the muzzle end of this barrel it is most likely there to secure the nose cap, remove it and the nose cap will probably fall off.

I am curious though how one is supposed to free float a barrel that is designed to support the wood attached to it. Nevermind, halfstock.

 

[MSW]

I've coned a number of barrels using Joe Woods tools, and what you have here is way shorter than the results i saw on my rifles. My cones are about an inch and a half long, and the taper is much less angled. The cone in your photos seems steeper and way much shorter, and the shape formed by the removal of the lands is not consistent: the end of the land at the two o'clock position has a much different end pattern than the one at the twelve o'clock, and that's different from the on at the ten.

This would lead me to believe that whatever coneing tool was used was not square to the axis of the bore, which would be a possible cause of your problems.

I would think that you'll need to go one of two directions: either try to re- cone it with a Woods tool, or cut at least three quarters of an inch off of the barrel and recrown it. The downside of this suggestion is, of course, that if it doesn't work and you have to cut a bit off the barrel, you're going to have to take at least two inches.



I'd try the Woods tool, but that's just my opinion, and it's probably worth about what you just paid for it.

 

[Fred_Dwyer]

how one is supposed to free float a barrel that is designed to support the wood attached to it.

What you said; the barrel should support the wood, and that is just by a couple little pins in lugs with elongated holes so there's nearly no force up or down, fore or aft.

 

[Rifleman1776]

That's a short taper cone, and doesn't look like a guide was used, and looks to only be about a 1/4"deep. It should be closer to 1 1/2 or two inches, and a very gentle taper. Instead of cutting it, I would consider getting a Joe Woods coning tool or borrow one for the .40, and recut to cone correctly. The crown itself looks to be very small, It may be a lot easier than cutting the barrel, and stock work. I think Keith Lisle cones all of his guns, and the fifty of his I have shoots 1" at a hundred yards. I've used Joe's tools to cone more than five guns with no degrade in accuracy. Looks like yours was done with a rat tail file, by hand with no guide. I don't have the .40, or I'd offer to loan out to you, Mine are all larger calibers. Cut the barrel, or recut the cone, or replace the barrel, seems like your three choices. Good luck!

Bill

I believe this is the final answer.

 

[Grizzled Roberts]

One thing to try before using the hack saw. Use a larger diameter patch, not thicker but bigger around. with some coned muzzles, as the ball reaches the cone the patch can slip off the cone. With a larger diameter patch, the ball will not slip off early. I solved one problem child like this.
Another thing to consider, The picture looks like a too deep crown. A Joe Lane Woods hand coneing tool could take out this problem. I have such a cone on my .40 caliber Squirrel gun. It works fine. I use .45 caliber patches with this rifle.

 

[Billnpatti]

A properly coned barrel will not loose any accuracy. I have coned all of my rifle barrels using a special coning tool that uses a properly sized jag as a guide. It cones the muzzle very straight and has not changed the accuracy at all in any of my rifles. However, if the job is not done correctly, accuracy can suffer. I suspect the answer to your accuracy problem lies somewhere else though. The thing to do is to determine the absolute best your rifle will do by following Dutch Schultz Muzzleloading Accuracy Method. Carefully examine your rifle for any obvious mechanical problems such as loose sights, loose screws, broken or missing parts, a warped stock, etc.. Look closely at your touch hole. If it is too big, accuracy can suffer from lack of a consistant breach pressure and a resultant lack of a consistant muzzle velocity. If it is much more than a few thousandths over 1/16 inch, it may be time to replace the touch hole liner. Do all of your test shooting from a bench using sand bags to hold your rifle steady. Start with thoroughly cleaning your rifle and a powder charge equal to your caliber. That would be 40 grains of fffG for your rifle. Then vary the powder charge up and down a few grains shooting 3 to 5 shots at each charge to see if your group tightens any at all. Try 40 grains, then 35 grains, 30 grains and then start going up from 40 to 45 gr., 50 gr., 55 gr and 60 gr. When you discover the best charge for your rifle, go to varying the patch thickness until you find the best thickness. Then, using your best charge and patch combination, try changing your lube and shooting 3 to 5 shots with each lube. If you will do this, you will know the load that it likes and the best your rifle can do. If you have not found a combination that gives you good accuracy, you can then began looking at other mechanical problems and consider having the muzzle re-coned by a gunsmith using a lathe to be sure it is absolutely straight.

 

[SR James]

Billnpatti: With all due respect, if you read my previous posts, you will see that I have done all of those things.

In response to some of the other questions/comments:
the glass bedding is at the very breech end only. There is no bedding compound at the muzzle or anywhere else in the barrel channge.
Grzrob, I tried .45 caliber patches with the same result, so I don't think the ball was slipping off the patch.
At this point, I'm debating whether to cut & crown or obtain a coning tool and finish the job.

 

[Black Hand]

I was using Goex 3Fg, charges varied from 30 to 60grs in 5gr increments.

Why stop at 60gr?

 

[Billnpatti]

Oops, 'scuse me. I didn't read all of the previous posts so I missed that post. :redface: Just trying to be helpful. :idunno: Wish you were living closer because I have a very good coning tool and would be more than willing to lend it to you. :thumbsup:

 

[SR James]

Black Hand: Probably because I was getting tired!
But 30 to 60 grs in 5 gr increments seemed a reasonable spread. Not getting anything near acceptable results over that range suggested maybe I should stop and re-evaluate.