Coning a smoothbore

[David Price]

I don't want to start another long discussion on weather coning a rifle muzzle is good or bad.  Just for the record, all my rifles have coned muzzles and they will shoot with the best of them. Nuff said!!

I just finished up building a swivel breach smooth bore gun for a customer.  My customer wanted sights on both barrels.  Today I sighted it in without too much fan fair.  It has  32 inch 54 cal.  both smooth Green Mt. barrels with the factory finish on the muzzle  end.    I dumped 65 gas of 2f Black powder down the barrels with a . 020 pre lubed patch and a .530 ball.  The ball took a little nudging to  get it started but then it slid down quite nicely. All the patches I could find were in perfect condition.   At that point the Devil stepped in and said  "David do you think this gun would shoot a tighter group if the barrels were CONED"?

That's the question for all you smooth bore shooters, has anyone tried coning a smoothbore for shooting a round ball, and how do you think it would effect the pattern when shooting shot?

My target was a six bull target at 25 yards, and I shot from the bench.
It was not my intention to spend the day working up the best load for it, I just wanted to get it in close for my customer.  but I was quite surprised as to how good it did group.

I am attaching the pictures of the target, and the gun.

David Price

[David Price]

Sorry I din't get the pictures in. I'll try again.

[David Price]

I'll try the pictures one more time.




















free image hosting

[Flint62Smoothie]

OH MY ... stunning! Have never coned a smoothbore, but I myself have thought about it too.

Missed seeing you at the SoVT snowshoe MZL biathlon - hope you are doing well!

[LynnC]

Beautiful gun.

Coning a smoothbore would make it a “spreader choke” for shot loads and would open up the pattern.  I have no idea about how it would affect ball loads.

A smooth crowning job would be my preference........Lynn

[Greg Pennell]

Gorgeous gun, Mr. Price!  Superb work...but as to your question, I have no idea. But, considering those targets, I don’t think I’d be inclined to change much of anything...she seems to shoot very well.

Greg

[Daryl]

That is a lovely rifle, David. In each group, 4 of the shots would likely rival many fellow's rifle groups

I would "finish" the crowning job to get rid of the ugly machine cuts, is all.

Kinda like my 20 bore's muzzle.

[Elnathan]

Bob Spencer has a coned smoothbore that seems to work OK: http://home.insightbb.com/~bspen/smoothbore.html

6th paragraph.

Bob posts, or at least used to post, over at the Muzzleloader Forums under the handle Spence10.

[Kevin]

Good Evening,

I don't have any first-hand experience shooting a coned smoothbore but an old relic of a gun I have is so confirgured. The muzzle is approximately .58 but quickly, probably no more than 3/4 of an inch down, drops to about .55 caliber.  How long it was that way before being put away is anyone's quess.

Take Care,

Kevin

[Daryl]

The reason I mentioned crowning the muzzle instead of coning it, was due to the fact it was already shooting very well
and there is no reason to change anything, other than perhaps, to make it easier to start the patched balls.

[JW]

I had a 28 gauge with a coned muzzle and it shot like a rifle under 50 yards. Of course, it very well may have shot the same or better before. I received the gun after it was coned.

[old george]

Not sure about coning but the pictures are definitely "minute of deer" 

george