Lathe cut crown...does it need deburring?

[noload]

I m getting ready to chamber and crown my first barrel. A couple questions keep popping up in my head concerning the crown. If I cut it with a sharp tool, should I travel from the center of the bore to the o.d., or cut to the center. I'm asking because of the creation of burrs as slight as they my be , will they need to be lapped with a grit paste of sorts? or do ya shoot the burr off ? Or will there be no burr??? I was thinking on a counter bore and 90 deg. type crown. Trying to get my ducks in order. Any advise will be appreciated. Pat

 

[butchlambert]

I indicate the bore and cut from the center out with a sharp tool. I just touch the crown with a cratex stick.
Butch

 

[noload]

Thanks Butch, are those rubberized cones in a dremel set the same as cratex ? can I touch that to the crown without the tool ?

 

[butchlambert]

I buy them from McMaster Carr. About .750X12". They come in different grits. Probably the same as a Dremel thing.
Butch

 

[STS]

Cut from the bore out. I have several ball end brass laps of different diameters that I use to lap the fresh cut crown with. I use 800 grit garnet lapping compound and it leaves a perfect finished edge on the crown. Run the lathe forward and in reverse to get both leading and trailing sides of the lands. Hope this helps.

 

[noload]

All your info was very helpful, I figured there as a couple ways to skin this cat. Hearing the different variations is a great help. I've got a couple barrels that need set back, problem is I won't have enough diameter to put a thread on it if I do a 2" cut back. do ya think pushing the reamer in 1/2-3/4" will help the accuracy from where its at now? Both barrels have about 3000 rds thru them, they have lost their peek performance (a 6br and a 6.5x47), I do not have a scope to check the condition of the throat. I'm assuming it will help accuracy but for a shorter duration. I'd like to get about 1000 more out ea. barrel before putting them in my garden. I've be shooting about 4000-5000 rds a year (practice and f-class 300-1000yds) Its been real fun but my bank acct. has been telling me to slow down. I think doing those barrels would give me good practice before doing my new Kreiger. Pat

 

[Larryh128]

It's just as easy cutting a recessed 11 degree (79) as a 90 & looks better.

 

[shortgrass]

All your info was very helpful, I figured there as a couple ways to skin this cat. Hearing the different variations is a great help. I've got a couple barrels that need set back, problem is I won't have enough diameter to put a thread on it if I do a 2" cut back. do ya think pushing the reamer in 1/2-3/4" will help the accuracy from where its at now? Both barrels have about 3000 rds thru them, they have lost their peek performance (a 6br and a 6.5x47), I do not have a scope to check the condition of the throat. I'm assuming it will help accuracy but for a shorter duration. I'd like to get about 1000 more out ea. barrel before putting them in my garden. I've be shooting about 4000-5000 rds a year (practice and f-class 300-1000yds) Its been real fun but my bank acct. has been telling me to slow down. I think doing those barrels would give me good practice before doing my new Kreiger. Pat

If ya' cut her off about 2" behind the crown ya' might!!!!!!!!! 3000rds.! She's done dude! They don't last forever.

 

[dennisinaz]

It's just as easy cutting a recessed 11 degree (79) as a 90 & looks better.

The 90s look better to me!!! ;D

 

[sailhertoo]

It's just as easy cutting a recessed 11 degree (79) as a 90 & looks better.

Not if you got a chit-com lathe and the compus or what ever it's called is backward and side ways, you don't know what is 11 deg from what.

But I'm thinking it don't matter what kind of crown you use as long as it's con-sin-trick.

 

[Larryh128]

Good reason not to get one. ;D