Gunsmithing Question

[onehole]

I,m learning fast and pretty much all of my lathe work is self taught,,,trial and error and making some horrendous mistakes along the way has gotten me into making a good standard of fit and finish to some of the things I have been working on,,,,my question,,,,11 degree crowning,,,cutting the 11 degrees is easy and with a very sharp tool to fashion it ,,,,,so where do we go from there gents,,,I know there are crowning tools ,,,pilot assisted etc,,,but I have also seen the muzzle then worked on with a brass cones/balls and abrasive paste to deburr the edge.,,,Ive tried this with a home made brass cone but to date my best results come from using a steel ball bearing and 320 then 600 grade abrasive paste,,,this seems to give a truly burr free edge with a minute or two,s light touch on the revolving muzzle,,I generally forward and reverse turn a couple of times,,,,,am I doing the right thing or is there a better way? I must say the end result through a 10x lens looks "dare I say" professional so am I on the right road or making hard work of it.,,,,,Im not concerned with making more of a protected type of crown but any guidance on crown finishing would be good,,,,thanks,,,,O

[bradders]

Get a piloted crowning tool from the likes of PTG or Manson and find the correct speed and cutting fluid

 

Finish to internet "look at me" standard with 240, 320, 400 emery

[onehole]

Get a piloted crowning tool from the likes of PTG or Manson and find the correct speed and cutting fluid

 

Finish to internet "look at me" standard with 240, 320, 400 emery

Mmmm,,, saw that coming I guess,,,,For the little I do I,m pretty sure I,m getting a good result without the expense.....I do wonder how many factory rifles have the "burr",,,most I suspect but no doubt quickly eroded away especially with centrefire,,,,bet 22 RF,s run with it a while though,,,,,,,,Thanks for reply anyway Bradders,,,,,,,O

[Big Al]

I,m learning fast and pretty much all of my lathe work is self taught,,,trial and error and making some horrendous mistakes along the way has gotten me into making a good standard of fit and finish to some of the things I have been working on,,,,my question,,,,11 degree crowning,,,cutting the 11 degrees is easy and with a very sharp tool to fashion it ,,,,,so where do we go from there gents,,,I know there are crowning tools ,,,pilot assisted etc,,,but I have also seen the muzzle then worked on with a brass cones/balls and abrasive paste to deburr the edge.,,,Ive tried this with a home made brass cone but to date my best results come from using a steel ball bearing and 320 then 600 grade abrasive paste,,,this seems to give a truly burr free edge with a minute or two,s light touch on the revolving muzzle,,I generally forward and reverse turn a couple of times,,,,,am I doing the right thing or is there a better way? I must say the end result through a 10x lens looks "dare I say" professional so am I on the right road or making hard work of it.,,,,,Im not concerned with making more of a protected type of crown but any guidance on crown finishing would be good,,,,thanks,,,,O

 

 

 

I wonder if you are confusing a sharp edge for a burr?

 

The reason I ask is that crowning is a fairly simple facing operation and with a nice sharp tool you shouldn't get any burrs providing you start your cut from inside the bore and work outwards. By sharp I mean a ground HSS, HHSSCo or micro-grain carbide tool.

 

The only times I would expect you to get a burr would be if you have cut inwards towards the muzzle or used either a blunt tool or a carbide insert which tears more than cuts.

[ejg223]

I would second Alans view.

Just can't understand how some make a huge effort to centre the bore, cut a fantastic 11 deg crown and then finish off by ramming a counter sinker into the bore to remove the burr.

edi

[onehole]

Mmm,,,perhaps I should practice and check tool finishing a little better,,,I do cut from the inside and by eye it looks really good,,,yes sharp edge,,,,,thing is ,,,with a 22 barrel I,m able to pass a lead pellet through and up to the muzzle and every time the pellet stops right at the edge,,,,its so small this burr ,,,well at least that's what I,m calling it but its there every time and easily removed with a light touch of abrasive paste on a 3/4 " ball bearing.In doing this the pellet passes smoothly on and out. Yeah thanks Alan ,,,will be looking at my tools!!,,,,,,,,,O

[Vermincinerator]

Onehole i finnish all my bores with a brass spherical tool specially for the job that i got from Brownells, a problem that you may encounter using a steel ball is, because, the ball is harder then the barrel steel the lapping paste will imbed into the edge of the bore/crown that you are a lapping, thats why these tools are made of brass, now will it effect accuracy? i have no idea, probably not.

 

Ian.

[onehole]

Onehole i finnish all my bores with a brass spherical tool specially for the job that i got from Brownells, a problem that you may encounter using a steel ball is, because, the ball is harder then the barrel steel the lapping paste will imbed into the edge of the bore/crown that you are a lapping, thats why these tools are made of brass, now will it effect accuracy? i have no idea, probably not.

 

Ian.

 

Thank you Ian,,,y es I was wondering why brass was being used,,,mmmm?,,,,,cant see any detriment in using the steel ball,,,,finish looks impressive but I will have a practice using some brass..........Like above comments and some PM,s to me are suggesting my tooling is not to the correct standard yet,,,,will be addressing this in the near future and have some more practice.,,,,its just one self taught operation that I would like to get spot on..regds ,,,O

[onehole]

Today !! off OP,,,but I have mastered the 4 Jaw,,,,,,,again self taught with the help of U Tube,,,,,on the "face of it" it looked really difficult but it really isn,t,,,couldn,t bear to keep looking at that tool in the box under the lathe any longer,,,,,,another door opens,,,,,,,,,,,Tell you what I,m glad I,m just a hobby machinist,,,I would hate to be stood over a lathe all day!!! I,ve noticed my ankles swell a bit at the end of a day on the lathe,,,not good ,,,but I guess the age is there!!......O

[Big Al]

Today !! off OP,,,but I have mastered the 4 Jaw,,,,,,,again self taught with the help of U Tube,,,,,on the "face of it" it looked really difficult but it really isn,t,,,couldn,t bear to keep looking at that tool in the box under the lathe any longer,,,,,,another door opens,,,,,,,,,,,Tell you what I,m glad I,m just a hobby machinist,,,I would hate to be stood over a lathe all day!!! I,ve noticed my ankles swell a bit at the end of a day on the lathe,,,not good ,,,but I guess the age is there!!......O

 

 

If you dont already have some try these cushioned mats, it makes standing on a hard floor all day a bit easier. I find them nicer than the older wooden duck boards we used to use.

 

http://www.ebay.co.uk/itm/ANTI-FATIGUE-HEAVY-DUTY-RUBBER-ANTI-SLIP-FLOOR-WORKSHOP-GREENHOUSE-MAT-5FT-X-3F/222602747478?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D20140122125356%26meid%3Dbba4f195bbe045e0a20d47d40488e736%26pid%3D100005%26rk%3D2%26rkt%3D6%26sd%3D131348045350&_trksid=p2047675.c100005.m1851

 

It also pays to have a tall stool handy, when Im profiling barrels I will sit and watch the machine to take the weight off my feet and back, it makes a big difference when you can. Also some air cushioned soles like Dr Martin work shoes are a good investment.

[onehole]

Aww bless,,thanks Alan!,,,yes I must take better care and consideration of myself,,,,should do ...worked in care for 10 years and the damage that can build up......neck and upper back areas too have started to be painfull,,,,,,hate getting old!!!!kind regds ,,,O

[Andrew]

For what it's worth, when I was in school they taught that you only feed the tool from the bore outward when crowning. Sharp tool. Light cuts. It has always worked for me.~Andrew

[Vermincinerator]

 

Thank you Ian,,,y es I was wondering why brass was being used,,,mmmm?,,,,,cant see any detriment in using the steel ball,,,,finish looks impressive but I will have a practice using some brass..........Like above comments and some PM,s to me are suggesting my tooling is not to the correct standard yet,,,,will be addressing this in the near future and have some more practice.,,,,its just one self taught operation that I would like to get spot on..regds ,,,O

I doubt very much that it would have any effect, i polish the bore at the muzzle so that a tiny witness of a few thousandths is visible on the edge of the grooves.

 

Ian.

[onehole]

I doubt very much that it would have any effect, i polish the bore at the muzzle so that a tiny witness of a few thousandths is visible on the edge of the grooves.

 

Ian.

have spent ages on lathe lately practicing with some barrel offcuts,,,,,what fun!!!,,eh?,,,,tell you what I,ve gotten my cutting tool as sharp as I can get it and have also tried various shapes and angles,,,,locked down as much movement in anything that moves other than what I need to move but I still get this minute burr that has to be dealt with......especially if its a rimmy or air rifle barrel,,,,lead aint gonna wear it away too quickly....You cant see this burr even with a lens ,,,but its there,,,,,,I can remove it with method as mentioned above and like you ian I have extended my final finish with an edge polish now using 800 grit paper on a shallow cone of brass or ball,,,works the same.......I really don,t think I can do this any better and just as you say it does leave the tiniest polished marks right on the edge....thank you for your input,,,,,,,,,,O

 

Could you share how you polish please ?

[bradders]

A trick I was once shown is to uses cotton bud to check if there is a burr.

If there is one then it should snag the cotton and pull a few wisps off

[Vermincinerator]

have spent ages on lathe lately practicing with some barrel offcuts,,,,,what fun!!!,,eh?,,,,tell you what I,ve gotten my cutting tool as sharp as I can get it and have also tried various shapes and angles,,,,locked down as much movement in anything that moves other than what I need to move but I still get this minute burr that has to be dealt with......especially if its a rimmy or air rifle barrel,,,,lead aint gonna wear it away too quickly....You cant see this burr even with a lens ,,,but its there,,,,,,I can remove it with method as mentioned above and like you ian I have extended my final finish with an edge polish now using 800 grit paper on a shallow cone of brass or ball,,,works the same.......I really don,t think I can do this any better and just as you say it does leave the tiniest polished marks right on the edge....thank you for your input,,,,,,,,,,O

 

Could you share how you polish please ?

Firstly, i use a freshly ground HSS tool and cut the crown from the bore back to the edge this way you will not create a bur but a sharp edge, i polish the crown with successively finer grit emery cloth down to 400grit, the edge of the bore to the crown is then polished with two brass ball lapping tools one loaded with 360 grit lapping paste and one with 600 untill the witness of a couple of thou can be seen on the edge of the groove.

 

Ian.

[onehole]

Firstly, i use a freshly ground HSS tool and cut the crown from the bore back to the edge this way you will not create a bur but a sharp edge, i polish the crown with successively finer grit emery cloth down to 400grit, the edge of the bore to the crown is then polished with two brass ball lapping tools one loaded with 360 grit lapping paste and one with 600 untill the witness of a couple of thou can be seen on the edge of the groove.

 

Ian.

Thanks ian,,,,similar method and end product then,,,,,,,could you some time perhaps have a go at a 177 or 22 barrel ,,,just machining inside to out and test with a lead pellet just to see what you experience?,,,,,,I think the topic is pretty much done now ,,so if you do get round to it could you PM me with what you find?/ regds ,,O