Anyone tried these recrown process, and how was the accuracy before/after?

http://www.youtube.com/watch?v...28fI&feature=related

http://www.youtube.com/watch?v...0mrI&feature=related

Recrowning by hand can give you good results but you need to go slow and not rely on doing it just by eye, as the video seems to imply. Additionally, while in general the directions are mostly accurate in the first video note how after the barrel was held vertical during the filing but was then moved horizontally, that should not have been done.

With the muzzle vertical you can visually examine the crown and keep it centered.

An example of this is to look at the drill being used for the crowning process with the barrel horizontal, now look at 1:50 into the video and you will see that the crown is not centered, it is pronounced at the bottom and has barely touched the rifling at the top or the bore. I suspect this rifle will not shoot well, or at least as well had the crown been cut concentric to the bore.

Having said all that, Mr Potterfield has made a ton of how-to videos on gun care and I think that generates a lot more good than harm.

BlaserGun,

Thanks for posting the links on crowning.
I have never done any crowning because I haven't had the need to do any. If I did need to recrowned a barrel, I think I would look into the crowning tools that Dave Manson makes.
Dave posts here occasionally, on the Gunsmithing Forum mainly.

Don

I've used the processes shown in the videos, along with pretty much all the other crowning methods including Dave Manson's hand cutters as well as my lathe. The videos are fine (other than having to watch & listen to Larry Potterfield, yuck!) and I regularly use the method shown even though I have access to others. Actually I usually use a combination of Manson cutters and brass laps, and have had splendid success over the years.

Two cautions: run the drill motor slowly, and run it in reverse just as much as you run it forward. High speed and uni-directional lapping can result in the rifling edges developing little 'wings', similar to a wire edge on a knife blade. Slow speed, frequent reversing and ensuring even pressure all around the crown are the keys to a good job here.
Regards, Joe

Here's my take on the video: First, on an old .22 like the one Larry is working on, there's no way I'd file the muzzle first. That's going to make it look really odd compared to the rest of the worn finish on the rifle. Polish the crown with the woodscrew and lapping compound and be done with it.

That being said, I would NEVER crown a high-power rifle like that under any circumstances. When I cut a crown if I can I use my lathe and I use precision ground ranging rods and dial in the bore to .0001"---that's 1-ten-thousandths of an inch. Then I use a super sharp carbide tool to cut an 11-degree crown. Then I polish the crown, most often to 600 grit.

On rifles that I can't practically put in the lathe I'd use Manson's tools, not a woodscrew.
Maybe the woodscrew method works just as well, but I wouldn't use it.

I agree a lathe is the way to go, but the brass woodscrew and lapping compound has been in successful use for a looooong time by gunsmiths and hobbyists alike. I know many gunsmiths who still do it that way and have been for 60 years!

quote:

Originally posted by airgun1:
I agree a lathe is the way to go, but the brass woodscrew and lapping compound has been in successful use for a looooong time by gunsmiths and hobbyists alike. I know many gunsmiths who still do it that way and have been for 60 years!

I'm sure somewhere in the world there are doctors who still think using leaches were a good idea. I will admit, a brass screw and drill motor is probably better than using a pocket knife.

There is no comparison between a proper lathe cut crown and the other methods. If a person is okay with 'getting close' then I suppose any method will be pleasing. But for those who want to eliminate ALL DOUBT, a proper lathe cut crown rules!

I will say this, a perfectly executed brass screw crown, is better than a poorly executed lathe cut crown.

quote:

Originally posted by Westpac:

quote:

Originally posted by airgun1:
I agree a lathe is the way to go, but the brass woodscrew and lapping compound has been in successful use for a looooong time by gunsmiths and hobbyists alike. I know many gunsmiths who still do it that way and have been for 60 years!

I'm sure somewhere in the world there are doctors who still think using leaches were a good idea. I will admit, a brass screw and drill motor is probably better than using a pocket knife.

There is no comparison between a proper lathe cut crown and the other methods. If a person is okay with 'getting close' then I suppose any method will be pleasing. But for those who want to eliminate ALL DOUBT, a proper lathe cut crown rules!

I will say this, a perfectly executed brass screw crown, is better than a poorly executed lathe cut crown.

I won't argue with that logic but I remember an article in Precision Shooting or similar rag by a guy who showed up for a silhouette match with a new pistol that went overweight for class. He found a hacksaw and cut an inch or more of the barrel to make weight and crowned it in a similar fashion to the brass button, much to the horror of his fellow competitors. It was a while back and I can't recall that he won the match but I think he placed very high if not. Great story but I don't think it would be the common result from such field modifications

Take a gander at your 'perfectly executed' lathe-cut crown under magnification and you'll most likely discover a fine wire edge if not worse. Another test for the freshly-cut crown is to take an extremely fine wire, finest you can find, and bend a 90-degree at one end. Now drag the short end forward inside the bore until it exits the muzzle, and I bet you'll notice a slight catch as the end of the wire hangs up on the raggedness left by the lathe tool. I agree that the lathe will cut perpendicular to the bore but it'll also leave a ragged & somewhat uneven edge if not cut in just the proper manner. The lap serves to remove the raggedness and to smooth the origin/termination of the rifling for better cleaning patch entry/exit.

BTW it's a proven fact that a slanted muzzle, if properly smoothed via the file-&-lap process, will still shoot tight groups albeit the group will be in a different location from the perpendicular crown's zero. AAMOF the change in location of the group on the target can be accurately predicted by observing the angle of the slanted muzzle.

I'm not saying that using a slanted muzzle is A Good Thing, but I am saying that tests have proven that perfect crown perpendicularity is not necessarily a requirement for good accuracy. IMO a smooth even edge is equally important.
Regards, Joe

quote:

Originally posted by J.D.Steele:
Take a gander at your 'perfectly executed' lathe-cut crown under magnification and you'll most likely discover a fine wire edge if not worse.

Not mine!

quote:

Originally posted by J.D.Steele:
Now drag the short end forward inside the bore until it exits the muzzle, and I bet you'll notice a slight catch as the end of the wire hangs up on the raggedness left by the lathe tool. I agree that the lathe will cut perpendicular to the bore but it'll also leave a ragged & somewhat uneven edge if not cut in just the proper manner.

If it does, something is wrong. A person who does this for a living should have that aspect of the trade down pat.

Westpac, I'll wager that your glass isn't strong enough or else your touch isn't delicate enough. Try a 10X loupe, for starters. Also try a linty cleaning patch pushed past your freshly-cut-but-not-lapped crown, and see if you don't end up with microscopic fibers pulled loose by the ragged edges.

Of course your expertise may be the exception to the rule...
Regards, Joe

quote:

Originally posted by J.D.Steele:
Also try a linty cleaning patch pushed past your freshly-cut-but-not-lapped crown, and see if you don't end up with microscopic fibers pulled loose by the ragged edges.

Of course your expertise may be the exception to the rule...
Regards, Joe

So this discussion has deteriorated to examining the crown using a 10x loupe and the possible presence of "Microscopic fibers"? Are you shitting me??? No one is suggesting you stop using your brass screw and lapping compound. If that works for you, then great!

BTW, I don't have a 10x loupe. Will this work?

The reason I suggested a loupe is that most anyone who's experienced enough to contribute constructively to this discussion is almost certainly a farsighted old geezer and will need some help seeing up close. If you're not that old then you probably don't have that much experience.

BTW I envy you that microscope, how about using it to examine one of your crown jobs up close?
Regards, Joe

quote:

Originally posted by J.D.Steele:
The reason I suggested a loupe is that most anyone who's experienced enough to contribute constructively to this discussion is almost certainly a farsighted old geezer and will need some help seeing up close. If you're not that old then you probably don't have that much experience.

BTW I envy you that microscope, how about using it to examine one of your crown jobs up close?
Regards, Joe

You don't need a lot of experience to contribute constructively to this discussion. It just takes a little common sense. A crown that is square to the bore, ends cleanly and uniformly, and in a concentric manner, wins. It doesn't take a loupe to see that.

quote:

Originally posted by J.D.Steele:
Westpac, I'll wager that your glass isn't strong enough or else your touch isn't delicate enough. Try a 10X loupe, for starters. Also try a linty cleaning patch pushed past your freshly-cut-but-not-lapped crown, and see if you don't end up with microscopic fibers pulled loose by the ragged edges.

Of course your expertise may be the exception to the rule...
Regards, Joe

I usually only do a crown in the lathe; after I cut it I take a peice of round cratex and polish the crown alternating forward and reverse on the lathe. By the way, that little microscopic burr you seem to be concerned with disappears after the first round down the barrel.