crown cutter

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Fixit

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im looking for a crown cutter...

ive seen a few that use a brass pilot to stabilize the cutter, but im not sure that they would last in the long run.

any suggestions for a good set up?


i got a stuck case in my vz58l and used a super long 5/16" carbide drill bit (1/4" shaft) to knock it out. would have worked great, but the back edge of the carbide bit into the crown when the casing finally came out.
ry%3D400

you can see the nick at the 3 o clock position


is this a 45 degree crown?
 
Fixit said:
where can i buy something like that?

what angle of cutter should i be getting?
Click to expand...

I prefer the 60 degree cutter. Dave Kiff at Pacific Tool and Gauge in Oregon can do it. JGS in Oregon can do it... any reamer maker can do it...
 
Do you actually notice a difference shooting it? I have seen some seriously nasty crowns on surplus rifles that still shot not bad. Some had to be cleaned up with a rounded bolthead, and lapping compound though.

If you want to do it right, it might be cheaper to take it to a good smith then to buy the reamer.
 
hmm these cutters arnt cheep... whats a smith going to charge to do it?

i havent shot it since i screwed it up, i guess i could give it a try
 
I would also be concerned about the possible damage you did to the rest of the bore with the "super long carbide drill bit".

You might want to have someone borescope that now.
 
I take it that you were using the shank of the drill, with the drill bit itself, outside the barrel?

Any tool and cutter shops near you? Not a huge job to convert a chucking reamer to have a pilot, and to cut any angle you want. You will need to tell them the exact diameters to grind to, but it can be done.
Probably not cheaper than just buying the reamer you need. Definitely not cheaper than just paying the guy that has the tools already.
From the looks of the picture,, the damage is not really great. A new 3/8 inch ball burr, maybe a bit larger, would clean it up without much drama. Turn it slow with a cordless drill, or by hand.

Or grab a jewelers file, and knock the worst of it off, and carry on like you were normal.

I would be inclined to start there. with a very small file, and if the barrel does not shoot as well as it did before, then look for something more to do to fix it.

It probably was not a sub-MOA shooter to begin with, and I got my doubts that you could make it a whole lot worse.

Get some mild steel rod and some heat shrink tubing for that particular job. Put the heat shrink over the rod to keep it from scratching anything while being beaten upon.

Cheers
Trev
 
How I crown Barrels:

I just take a round head brass screw and some lapping compound, I want the screw head to be just a little bigger than the bore. Now I use diamond lapping compound, 1200 grit, but silicone carbide 600 grit has worked just fine before. I put the screw in the drill, and swivel it around as I cut the crown, never having the line of the chuck of the drill in line with the barrel.

Oh, I forgot the most important part: Shove a rag down the barrel just below the crown, so you do not have a big project cleaning it after it is done. This does not take very long, maybe less than a minute with diamond, so sotp and look every ten seconds or so to see if you have gone far enough. It is easy to see when you have cut far enough.

Once you are happy with your crown, spray some solvent to disolve the grinding compund and clean it as clean as you can, then push the rag out through the bore, clean the end again with solvent and put some bluing paste on it.

I have shortend a barrel, and crowned it this way and it shot just fine.

Maybe not like the pro's do it, but it works well, and it is almost impossible to seriously screw anything up.
Al
 
redlaker1 said:
sounds like the method that is described in this video

http://www.youtube.com/watch?v=OorpZlG28fI
Click to expand...

Wow!

Betcha THAT video has drummed up a pile of business for gunsmiths all over the place!

The crown on that one actually looked worse to me, after it was molested with file and sandpaper. And brass screw and lapping compound...

I'd be more a believer in what was shown, had they shot it, or at least claimed to, and then gave some indication of improvement, but they didn't.

I count myself a fair hand with a file (not great, maybe good, when the stars aligned,but fair is something I would defend), but have seen enough butchers grinding the heck outta whatever is under their file, to know that I wouldn't hold much hope on the average guy grabbing a decent file and having at the muzzle end of a barrel. Lord knows it's hard enough to find a good clean cutting file in a shop that purports to be full of them...

I figure it would take about three days and a box of brass screws to cut away a significant dent, like the one on Fixit's muzzle. Aside from that, the amount of material that would have to be filed off. Oy yoy!

What's the sitrep on it, by the way? Shooting again? If so, how so?

Cheers
Trev
 
I wasnt endorsing that method just to be clear. I just read the post before me and it reminded me of that video that I had come across on youtube a while ago.

I agree that if you don't know what you are doing you should just take it to a professional, as well I am sure a fair bit of many gunsmiths time is put towards cleaning up average joe's attempts at home gunsmithing
 
I've cut and crowned 3 rifle barrels now..... using the brass bolt and lapping compound. 2 are fine shootin huntin riifles and the other is a sub MOA m14 with a non chrome lined barrel.

is that barrel you dinged chrome lined?? cuz this can open up a whole nuther can of worms
 
well, i took a small fine file and took the bur off,
went out shooting and didnt notice any difference shooting at clay pigeons from a standing position.

and yes it is a chrome lined barrel (VZ58L)
Im in vancouver
 
Good!

Glad it's working out!

According to what you read in magazines and online, the consequences of a ding in the crown area range from a potential grenade, to having the genitals fall off you and the next seven generations of offspring. All a bit overblown.
Anyone ever see any documented, controlled circumstances effort to see just how much difference a ding in the crown makes?

It probably opened up your groups by a couple thousandths of an inch at 100 yards. Or not.

Cheers
Trev
 
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