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Have You Done A CROWN Job At Home?

8K views 20 replies 19 participants last post by  Maineiac 
#1 ·
After a recent post by an M.O. about a crown problem on his Marlin .444 I looked for DO IT YOURSELF crowning and found this MIDWAY video showing it is very simple to perform a crown job.

How many of you M.O.s have done this and is it as easy at it is shown in this video? GB45

 
#5 · (Edited)
When it comes to filing as shown in video, there is a very easy way to insure you are keeping the muzzle even and flat.


Note, the importance of instructions to dress file with chalk cannot be over emphasized and do it often when filing. It only takes one small piece of metal clogging the file to ruin whatever progress has been made.


When first filing with fine mill file, do so lightly and only file until file marks show across the muzzle. Then file 90 degrees across from first filing, at first one will see a cross hatch pattern, file only until all cross hatch is removed. Then go back to original filing position and repeat removing cross hatch pattern, repeating process back and forth until satisfied.


One can take strips of different grit cloth and place on file flat or piece of wood, repeat the process used for filing, completing with a fine grit to obtain best finish.

On a side note: Once a file has been used on iron or steel, it becomes next to worthless for filing brass. I keep two sets of files and make sure they do not get mixed.
 
#7 ·
Yep, it was my second rifle project on an old Sportco .22, and works a treat.
You are probably wondering what the first project was, well it was taking the action out of the stock. LOL.
 
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#9 ·
The round ball ended tool is about the ONLY way to achieve a crown that is perpendicular to the bore. And only then if the ball remains round. Rotating around as shown in the video best reaches that goal. Even if you are very slightly off square the radius of the lapping tool will automatically correct for a minor out of square cut. This is a dirty little secret that gunsmiths don't want us to know about. It will fix a minor, accuracy harming ding at the edge of a crown. Of course, thoroughly clean any lapping compound from the barrel! AC
 
#10 · (Edited)
I have it done with a gauge !!!that the korrekt angle is to the Barrel inside.
look at my accurate pictures -and the answer from Ing. Mayerl
LINK:
Ing. Michael Mayerl
Betreff des Beitrags: Re: 11° Mündung -Senkung
Verfasst: Sa 3. Mär 2012, 14:04

.50 BMG





Registriert: Do 11. Nov 2010, 22:57
Beiträge: 911
Wohnort: Zeltweg - Styria - AUSTRIA
oe6odd hat geschrieben:
Nehme aber immer gerne Belehrungen über Mechanik ,etc. an.Vorausgesetzt jemand weiß mehr als ich über ein Thema.
Ing. Mayerl z.B.Bixn Andy und so weiter.
Diese Herrn sind sicher Profis und haben das lange gelernt.
Ich dagegen bin nur Self made Man.



Du hast es mit Dorn um Messuhr zentrisch ausgerichtet und dem Bild nach auch sauber gedreht.
Von mir bekommst ein 1+


Die Industriemündungssenkungen sind wirklich nicht der Bringer und meist sogar so richtig schön exzentrisch. So gut nachgesenkt wie bei dir kann man schon wieder eine mögliche Fehlerquelle elliminieren - möglich deshalb, weil eine exzentrisch angesenkte Mündung nicht gleich Schussleistungsdefizite bedeuten müssen, aus Erfahrung verbessert eine richtig angesenkte Mündung die Streukreise aber in vielen Fällen.

Richtig wird auf einer Drehmaschine gesenkt - genau wie du es auch gemacht hast.
Von Senkern halte ich nicht viel - die funktionieren nur mit kalibergenauer Führung und sollten nur in Sonderfällen genutzt werden, wenn der Lauf nicht gespannt werden kann.

_________________
Ing. Michael W. Mayerl - Ing. für Waffentechnik und Maschinenbau
http://www.styriaarms.com
 
#11 · (Edited)
This dodger had done 3 bbls...cut shorter, smoothed, and "crowned." No complaints. All shoot to quarters at 100m, i do my part.
Process:
Run patch to near end of bbl to limit cleaning...;
Carfully use hacksaw to remove barrel section desired to no less than 16.5 inches;
Smooth muzzle area, using very fine sanding disk in drill ( I stick a fitting drill in very old Grizzly - low cost - machining jig in the chocks of a big box store's portable - small - bench and tighten;
Smooth muzzle area again - (I use a polish wheel and the black stick of compound polisher on cloth of disk...0
Then Stick round screw head brass or SS bigger than bore, in drill chuck, apply fine valve grinding goo to the open bore;
Start screw spinning and push barrel onto screw, taking care to not let slip, and grind away...rotating barrel as disired...round screw head will center;
Smooth area muzzle area again;
Remove patch...
Can use tem bluing (I use Skinner Sight's stuff) Let wit for half-hour, redo, let sit...polish.
Clean and shoot...
Voila! Saved a bundle...
 
#12 ·
I've shortened several shotgun barrels for Cowboy Action. Hacksaw and a mill file. Just keep 'em as square as you can.

I haven't watched the video, but there are hand tools for cutting a muzzle and crown. Basically it's a cutter with a barrel pilot of mandrel to keep the cutter square. It can be hand turned to cut the new crown. Afterward the crown would still need to be polished.
 
#16 · (Edited)
I use my hand tool designed for small engine valve seats. The carbide cutters are super sharp and cut very smooth. I've enjoyed great success, had to make my own pilots for the .44 and .45 pistols. Some Italian blackpowder revolvers come from the factory with no crown, just the 19th century style flat cut. Accuracy really improves with a fresh cut crown.

The automotive cutters give you a choice of 15, 30, 45, or 60 degree crown. I've had excellent results with the 45 degree.
 
#17 ·
perhaps a small improvement in the functionality of the Brownell's manual cutters could be obtained by using a pilot with a diameter smaller than that envisaged, and compensating the width with a short sleeve in synthetic material or brass. If the sleeve is so tight fit in the barrel that it can be inserted with some effort, without rotating, it prevents lands & grooves from being directly affected by the entry of mixed cutting oil with fragments made abrasive by rotation. This becomes more important if, when finishing, a pad (hide/rubber/etc.)is placed between the cutting face and the muzzle, sprinkled with jeweler's rouge or equivalent, for polishing. I used this method on the muzzles of the 8mm Mausers., therefore it should be even easier in larger calibers, when working manually muzzle-up. I don't know if Brownell's offers such a solution today, (or ACME catalog
perhaps ?)and I still imagine I haven't invented anything, but at the time I was happy with the result.
usual 2c.
 
#18 ·
1 dodge a engineering friend made for me was a sliding locking sleeve to go over the cutter body. This when locked off near the end of the cut would gradually reduce the cutter contact and reduce cutter chattering. I would back the sleeve off about 4th and lock it off, as the cutter took out the last 4th it would finish with little more than a polishing cut and then just burnish the crown. At all times make sure the swarf does not build up between cutter and crown. Gar.
 
#19 ·
I've done two or three with a tool bought from Brownells. Cut with a new, sharp hacksaw, fine file to get as square as possible. Then hit it with a greased 90 degree cutter and then with the 11 degree one. Steady does it to avoid chatter. Put a greased patch and grease in the bore to catch any chips just in case. Clean and done. worked well.

Luisyamaha
 
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