Recrown ?

[boltman223]

I was wondering if it is necissary to chamfer the muzzle after it has been recrowned and what to use to chamfer it with?

 

[Erik Cortina]

I was wondering if it is necissary to chamfer the muzzle after it has been recrowned and what to use to chamfer it with?

As far as I know, just leave it as is. You want a razor sharp edge on the inside but burr free.

 

[jscandale]

When I finish the barrel with a crown, I always (unless instructed not to) put an ever so slight chamfer on just the lands of the crown. It is so slight, you can hardly see it unless you look very closely. Most bench rest guys say no chamfer and its hard to argue with it, but I doubt that a chamfer could hurt unless the bore is not properly indicated resulting in an offset chamfer.

JS

 

[DOGCAPPER]

Why spoil good work on a crown sticking a chamfer in it...LT

 

[Preacher]

With a good sharp cutter, lots of fluid, high speed, and slow cutting, no touch up is needed on the crown..

 

[Tozguy]

My preference is for a 45 deg. chamfer. Done properly it is just as accurate as a sharp 90 deg, edge but it makes the crown more durable.

 

[Larryh128]

Toz,
Most of these guys are cutting a 79degree(11degree) crown, not a 90 so it already is buried enough to protect it.

 

[Tozguy]

When I mention durability it refers to wear from cleaning and from gas cutting.
The picture is a muzzle cut according to a reputable gunsmith. As you can see it has a counterbore that has a transition from 90 deg. to 79 deg. The bore has a generous chamfer.

 

[Tozguy]

Another pic taken with different lighting.

 

[X Ring Accuracy]

I will use a cratex to knock the razor edge off. I haven't seen any accuracy differences versus not doing it.

 

[Larryh128]

Toz,
Nice crown. Sako has crowned their rifles 90 degree with a 45 chamfer for years so it can't be all bad. I crown mine the same recessed 11 degree only because I think it looks cooler, only difference is that I don't do the 45 degree chamfer. I'm sure that they both shoot.

 

[Tozguy]

Not pretending to be an expert but I haven't seen any conclusive evidence that one muzzle style or profile is inherently more accurate than another when both are properly done. If I recall correctly, it may be Speedy who recommends a 90 deg cut because it is less sensitive to a lack of precision in doing the crowning work, not because it is more accurate.

Despite the durability advantage I see with a chamfered bore, I would only want one if it would be done with great precision.

 

[Larryh128]

Toz,
A floating chamfering tool will absolutely center itself.

 

[tclaunch]

With a good sharp cutter, lots of fluid, high speed, and slow cutting, no touch up is needed on the crown..

This is how I do mine!!

I tell ya great minds...... 8)

 

[STS]

That's a lot more of a chamfer than I put on a crown. I lap a tiny chamfer with a brass lap and 800 grit garnet compound. It leaves a razor sharp, beautiful crown and has proven to be very accurate.

 

[GrocMax]

And 45 chamfers can be cleaned up with the appropriate sized precision ball mounted on a piece of tubing or stick, and lapping compound.

Blast pattern at muzzle gets 'lopsided' or assymetrical, (I'm assuming from cleaning brush/rod damage) touch it up with the ball, blast pattern goes back to symmetrical, even pattern.

Appropriate sized ball is found by drawing the exact config in CAD, and matching up the correct diameter to touch the center of the chamfer. Precision ball brg balls can be had in a wide variety of diameters.

 

[jscandale]

Suprisingly, this topic comes up often with each contributer stating "the way I do it is the best". I have done all of the crowns and I have come to the conclusion that the best crown is the one that pleases the end user the most.

JS