cutting and crowning a barrel

Wv_mingo327 · Tuesday at 1:58 PM

I’m in need of some help/ guidance. i recently picked up another cva mnt rifle appears to be older kit gun. my concern is the rifles crown or rather a small cluster of pitting about 1/4” directly inside the muzzle, the rest of of barrel is a mirror with no pits of rough spots i have shot the rifle with several different thickness patches as well as different powder charges and while it will group reasonable it just doesn’t group as well as some of my other mnt rifles. my question is do you guys think it could be from the small place near the crown? and will cutting say 1/4” to 5/16” off and re crowning affect the rate of twist? it has a 1/66. i’m comfortable with cutting it my self and crowning as far as doing the work goes or would i be better off to send it to someone and have it professionally done? I tried to get some pics but there not the greatest so i do apologize but you can see the place in barrel i’m referring to as it looks like a ring all the way around but the riffling is still visible all the way to the end of barrel.if for some reason some of the more experienced members feel this is not what’s affecting my groups i will try any suggestions before cutting/crowning.just looking for some help and any input or info will be greatly appreciated.

The Crisco Kid · Tuesday at 2:28 PM

One of Joe Woods coning tools will clear that right up and you will be able to toss your shorter starter.

https://www.muzzleloadingforum.com/threads/muzzle-coning-tool.121223/

Phil Coffins · Tuesday at 2:34 PM

I would cut and crown that barrel. How a barrel lets go of the projectile is important. If coning it I prefer a much shallower job then I’ve seen done with the Joe tool. The barrel on the left is how I crown a barrel and load without a short starter. The other may work well but you can see the cone doesn’t go deep enough for your issue.

IMG_0421 by Oliver Sudden, on Flickr

LonestarShootR · Tuesday at 3:04 PM

If you have a lathe with inboard/outboard spiders and can coaxially indicate the barrel to where the crown is absolutely perpendicular to the bore I would say go for it.

rafterob · Tuesday at 3:43 PM

Someone did a really poor crown job on that rifle. Also, I can't tell from the pictures what has marked the inside of it. I would say cut and crown also.

Wv_mingo327 · Tuesday at 4:32 PM

rafterob said:
Someone did a really poor crown job on that rifle. Also, I can't tell from the pictures what has marked the inside of it. I would say cut and crown also.

i was thinking the crown was pore quality compared to my others and the inside is my concern it’s a ring all the way around that’s clusters of pitting it’s no more than 1/4"-5/16” deep in the barrel

Wv_mingo327 · Tuesday at 4:34 PM

LonestarShootR said:
If you have a lathe with a spider and can coaxially indicate the barrel to where the crown is absolutely perpendicular to the bore I would say go for it.

i would be using a friends shop he’s a machinist by trade but told me up front he’s never messed with anything of this nature but i was more than welcome to bring it over and he would cut it where i wanted so that it was true then i would haft to recrown it myself

Wv_mingo327 · Tuesday at 4:36 PM

The Crisco Kid said:
One of Joe Woods coning tools will clear that right up and you will be able to toss your shorter starter.

https://www.muzzleloadingforum.com/threads/muzzle-coning-tool.121223/

would this tool be able to cut deep enough into the barrel cut out the pits without cutting the barrel shorter ?

Wv_mingo327 · Tuesday at 4:38 PM

Phil Coffins said:
I would cut and crown that barrel. How a barrel lets go of the projectile is important. If coning it I prefer a much shallower job then I’ve seen done with the Joe tool. The barrel on the left is how I crown a barrel and load without a short starter. The other may work well but you can see the cone doesn’t go deep enough for your issue.
IMG_0421 by Oliver Sudden, on Flickr

I had read somewhere before about some of the coneing tools but was unsure if it would be able to cut deep enough to clear it up it’s no more than 1/4"-5/16" deep into the barrel if i do cut it i wouldn’t haft to even recut the dove tail for the front sight just the barrel and underrib and shorten the ram rod maybe a tad

rich pierce · Tuesday at 4:40 PM

Back in the day we cut them off with a hacksaw, cleaned up the muzzle with a file, crowned the bore with a burr then sandpaper.

Flint62Smoothie · Tuesday at 4:43 PM

I'd re-crown 1st and see how it shot, as that crown is BAD!

But also, different barrels like different loads ... if you haven't yet tried this method ... you should.

https://www.muzzleloadingforum.com/...d-development’-to-find-the-best-group.169960/

Wv_mingo327 · Tuesday at 4:49 PM

Flint62Smoothie said:
I'd re-crown 1st and see how it shot, as that crown is BAD!

But also, different barrels like different loads ... if you haven't yet tried this method ... you should.

https://www.muzzleloadingforum.com/threads/importance-of-‘load-development’-to-find-the-best-group.169960/

i have tried a few different patches an lubes as well as different powder charges i’m shooting pyrodex select threw it and so far a .15 patch and .490 ball give my righted group at 50 yards which is around 3-4 inches but it seems that every 4th to 5th shot it throws a stray flyer that could be anywhere on paper that is my major concern with it. I never thought of it but one could re crown and try it then before cutting the barrel that may clear things right up.

ronaldrothb49 · Tuesday at 7:48 PM

Wv_mingo327 said:
would this tool be able to cut deep enough into the barrel cut out the pits without cutting the barrel shorter ?

With Joe's tool you can taper the bore up to 1 3/4" deep. In effect that puts the crown of your muzzle down into the bore. If you go that deep it pretty much takes the rifling out at the end of your barrel.

Greg Y · Tuesday at 8:18 PM

I chamber and thread rifle barrels for unmentionables at my shop. Here's a pic of how I setup and indicate before I cut on a barrel. Your machinist will understand.

Greg Y · Tuesday at 8:28 PM

I've also used 8ga copper to allow the pivot....but it's not as easy imo...but works well if you pay attention.

Greg Y · Tuesday at 8:32 PM

I don't have any pics of my heavy 10 lathe, but I have a similar spider on it. He could pound a bushing over the barrel and grab it in a steady also. With a lathe this will be 101 work.

Rawhide67 · Wednesday at 9:07 AM

Consider a back bore. I did this on an old lever action unmentionable. Made a world of difference in accuracy. You don't have to worry about the front site dovetail being moved, and the reamer leaves a nice clean recessed crown.

andy52 · Wednesday at 9:27 AM

If you don't have access to a lathe it can be done by hand with a hacksaw, squaring tool, hand cutter with a pilot, and a hand crowning tool with a pilot.

Greg Y · Wednesday at 10:17 AM

It's also worth try to run a lap through it. Pour the lap and let it tell you what it needs.

ZUG · Wednesday at 11:59 AM

I would try the least destructive method first. First clean up the bore - then shoot it if it does not perform well then cone it - then shoot it if it does not perform well then cut and recrown it.

cutting and crowning a barrel

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