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More Important Than Biden, Trump, Ukraine, Ballistol and Pietta Combined.....Muzzle Coning.

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My take is if you haven't coned a barrel and shot said M/L, any speculation on the possible disastrous results is null and void.

I on the other hand, I just coned my first barrel, one that was a poorly done rebore that had two loose spots from the rear sight down and bore so tight I had to order a .526 mold to have something I could start without a hammer. The barrel shot a 3" group at 50 yards and cut patches in spite of re-crowning the muzzle and giving the entire bore the scotch bright treatment.

I used a Joe Wood coning tool and opened the bore to the point I could thumb start a .530 ball half way in with a dry patch.

coning done.JPG


The coning did change the point of impact, with a little sight and load adjustment the barrel shot better than it ever did.

I was shooting low left and chasing holes with sight adjustment, hence the scattered holes to the left. I bumped up the powder to 85 gr to raise up the point of impact, I didn't want to file the front sight down anymore.

My front sight turned out to be bent, in the process of straightening it I wore the brown off and it was way too shiny. On my first shot the sun had come out behind me and I couldn't tell where the tip of the shiny front sight was against a white background, my guess was off and I shot a little high.

A great friend gave me all his B/P stuff when he died and I remembered a can of sight blackening spray in his range box. I found the spray and blackened my shiny front sight so I could see it in the sunlight and took two more shots, BINGO!

My last 3 shots are circled, 50 yards, .530 ball, .015 ticking patch cut at the muzzle and a dry wool wad over 85 gr of Goex 2F using a 6 o'clock hold off sandbags

I also have 75 year old eyes and recent cataract surgery on both eyes. I can't see a very clear rear sight, but the front is crisp and in focus.

coned haines.JPG


The tool;

coning sandpaper installed.JPG
 
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Let's argue about something so important that it may very well impact the longevity of America as we know her.

Let's argue about Muzzle Coning and the benefits or detriments of muzzle coning.

Personally speaking, I would never ever grind an angle at the muzzle of a rifle that would eliminate some of the rifling. Never. Ever.

I think a bore/muzzle/projectile should be as tight as a tick. I want no clearance/air space between projectile and bore. I want that projectile out of the bore and gone before the gases behind it even have a chance to think about exiting the muzzle.

When a muzzle is coned, you're giving a ton of hot gases a chance to pass over the projectile and create a possible disturbance in its flight path as the projectile is exiting the bore. The gap between the projectile and bore is tiny but it's still a gap.

I fully understand the desire to have a patch and ball below the muzzle for easier ramming. But at what cost?

Ready.....GO!
The folks at Rice barrel Co. would agree with you on that. Your better off buying their top grade bc they load so smoothly which I speak from experience
 
I have owned two Rice barrels; one was pretty slick (Kibler SMR) but the other needed a rigorous scotch bright treatment to get it to smooth out. I bought the rough one (new never used) off eBay 15 years before I bought the nice one in the Kibler rifle.

All my rifles are well used hunting rifles, thumb starting a ball in the heat of the battle is a joy compared to fumbling with a short starter.
 
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My Kibler SMR kit came with a .40cal 44" Rice barrel, coned by the manufacturer. If Jim Kibler is selling coned barrels as standard and his rifles shoot straighter than laser beams they cant be all that bad...

Chris
 
F.W. Mann's book The Bullets Flight deals quite completely with muzzle damage and how it affects group size and point of impact.
 
Real bullets with a rebatted base were designed to get the thing out the muzzle with minimum effect from the passing gas. Perhaps putting rebatted bases on round balls would solve the problem of much debate.
Shooters using techniques that involve passing gases? Would this cause unpleasant fouling?
 
To the naysayers, isn't coning just an exaggerated crown?

The muzzle on my Jaeger is crowned (only rifle I have that is) and it has won many matches shot off hand, which is the only type matches I shoot in with a ML.

Bench guns are............well, they are bench guns.
 
It depends on who is doing the altering and the equipment they use. For instance, I have never gotten an even crown with sandpaper and my thumb so I made a simple crowing tool out of hickory with a tight fit bore guide that cuts a very even crown.

crown cutter.JPG


crown 2.JPG




I would never try to jug choke my own expensive fowler barrel, I don't have the right equipment or knowledge.

I can handle coning a barrel, the right tool and instructions make it pretty much foolproof and hardly a crapshoot. To make sure, I did searches on barrel coning read the posted results of a bunch of people who had used the Joe Woods tool, I didn't find one negative response or anyone whose barrel was damaged in the process. After researching the matter I ordered the tool.
 
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It depends on who is doing the altering and the equipment they use. For instance, I have never gotten an even crown with sandpaper and my thumb so I made a simple crowing tool out of hickory with a tight fit bore guide that cuts a very even crown.

View attachment 193739

View attachment 193740



I would never try to jug choke my own expensive fowler barrel, I don't have the right equipment or knowledge.

I can handle coning a barrel, the right tool and instructions make it pretty much foolproof and hardly a crapshoot. To make sure, I did searches on barrel coning read the posted results of a bunch of people who had used the Joe Woods tool, I didn't find one negative response or anyone whose barrel was damaged in the process. After researching the matter I ordered the tool.
Yes, whether crowning or coning if you do not know what your doing find someone who does to do it for you.
 
I have coned 2 barrels. One is a 54 and the other is a 40.
Both are hunting rifles and both shoot just as well for me as they did before the coning. I also have a very fine 50 cal match rifle that I will not cone. No use messing with something that nice and that accurate.
 
I have coned 2 barrels. One is a 54 and the other is a 40.
Both are hunting rifles and both shoot just as well for me as they did before the coning. I also have a very fine 50 cal match rifle that I will not cone. No use messing with something that nice and that accurate.
If I had a dedicated match rifle, I wouldn't mess with a gall darn thing. My rifles that I shoot off hand is a different story. I've crowned two rifles, and I see no difference. Being able to start a ball and patch by hand and using a ramrod to drive the ball home without the benefit of a short starter is A-OK in my book.
 
What is cone vs crown? At some point a crown has enough taper to make it a cone.

Semantics aside, I do my crowns on a lathe. The bore is indicated to be true and centered. I then make a crown/cone that takes the lands over about 1/8" from bore to groove diameter. Then the edge is gently rounded over. It is done with a sickle shaped cutting tool. The polishing is done to 600 grit paper while in the lathe. The angle of the crown is progressive from a few degrees to 90*. The shape is like a micro version of a trumpet bell. I always get good a result with this. So far my rifles are very accurate and easy to load. I had an exception recently. The bore on that one was defective and was replaced by the maker. The crown had nothing to do with it.

Because of my perfectionistic tendencies I would never do any crown or cone with unguided manual tools. I also have nice lathe : ) . In the modern target rifle world a tiny crown defect can be disastrous. I infer that a messed up crown can only have a negative effect on ML accuracy.

 
I had recently re-crowned the barrel of my first build with the above tool, before I recrowned it, it had a history of throwing fliers, I also added a homemade peep sight because it had been at least 13 years between when I made the gun, my eyes had passed 73 and had gone downhill a bit.

I envy anyone who has the lathe tools to do top notch work but these are out of the question for most of us hobby builders so we make do with what we have.

When I re-crowned this rifle (it cut patches on ball starting) with my thumb and sandpaper, it looked terribly off center. I made the above crowning tool with a tight bore guide to keep it centered and recut the crown.

I shot the gun a good bit after the second re-crowning (a flintlock), no more fliers, I flinched a little with the first shot on this target which was the latest one from a few months ago, then I settled down for the next two at 50 yards.

Like I previously said; some of us have to make do with what we have.

peep group 2F.JPG
 
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