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Gunsmithing Crowning a Barrel

6.81star

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Nov 26, 2008
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Is it necessary to have a crowning tool when crowning a barrel or can i use the tool post set at the angle needed. I am threading and recrowning my 700P for a suppressor does it matter between a 45* or 11*. Also do ar-15 barrels have or need a crown. thanks any help appreciated
 
Re: Crowning a Barrel

i don't use a crowning tool. i use a very sharp small carbide boring bar to cut the crown. i set the compound to the angle i want and feed it slowly by hand. i also feed from the inside out to keep from raising a bur in the bore.
 
Re: Crowning a Barrel

Yep , just do a little step , don't worry about using the compound at all.

I realy like the way Roscoe does his with the cap acting like the outer lip for protection when the suppressor is not screwed on.
 
Re: Crowning a Barrel

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 6.81star</div><div class="ubbcode-body">Is it necessary to have a crowning tool when crowning a barrel or can i use the tool post set at the angle needed. I am threading and recrowning my 700P for a suppressor does it matter between a 45* or 11*. Also do ar-15 barrels have or need a crown. thanks any help appreciated </div></div>

Star,

As long as your crown is cut with a sharp tool and the barrel was indicated by the bore, you'll be GTG. No crown is better than another as long as they're cut right. If you’re threading for a suppressor, just crown prior to removing the barrel from the lathe. For field rifles I really like the USMC style crown, .090" deep with a 45 degree pull back and a 45 degree chamfer on the outer diameter of the barrel. I also put a slight 60 degree chamfer where the bore meets the crown.
 
Re: Crowning a Barrel

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 6.81star</div><div class="ubbcode-body">Is it necessary to have a crowning tool when crowning a barrel or can i use the tool post set at the angle needed. I am threading and recrowning my 700P for a suppressor does it matter between a 45* or 11*. Also do ar-15 barrels have or need a crown. thanks any help appreciated </div></div>

Star,

As long as your crown is cut with a sharp tool and the barrel was indicated by the bore, you'll be GTG. No crown is better than another as long as they're cut right. If you’re threading for a suppressor, just crown prior to removing the barrel from the lathe. For field rifles I really like the USMC style crown, .090" deep with a 45 degree pull back and a 45 degree chamfer on the outer diameter of the barrel. I also put a slight 60 degree chamfer where the bore meets the crown.
</div></div>

+1. I do it basically the same way, but without the chamfer where the bore meets the crown. I also had a carbide tool specially ground to put a radius on the inside edge of the step. Doesn't change the functionality, but adds a very nice, clean custom touch.
 
Re: Crowning a Barrel

My benchrest rifle books say an 11deg crown was/is the best. However even though the books are newer it looks like they were written in the early 80s. Can any of you gunsmiths share your thoughts on this.
I have done my crowns on the lathe with the bore dialed in. If you have a lathe it is easy to do. As for an angle recomendation I am no help there.
 
Re: Crowning a Barrel

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: maccrazy2</div><div class="ubbcode-body">My benchrest rifle books say an 11deg crown was/is the best. However even though the books are newer it looks like they were written in the early 80s. Can any of you gunsmiths share your thoughts on this.
I have done my crowns on the lathe with the bore dialed in. If you have a lathe it is easy to do. As for an angle recomendation I am no help there. </div></div>

This ain't benchrest, and what was the reason they said it was the best?
 
Re: Crowning a Barrel

I had my guy do a 90* (square bore/muzzle-no chamfer) crown in a recessed muzzle on my last barrel I had done. So far I'm happy with it, but I may not be able to shoot the difference.
 
Re: Crowning a Barrel

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HateCA</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: maccrazy2</div><div class="ubbcode-body">My benchrest rifle books say an 11deg crown was/is the best. However even though the books are newer it looks like they were written in the early 80s. Can any of you gunsmiths share your thoughts on this.
I have done my crowns on the lathe with the bore dialed in. If you have a lathe it is easy to do. As for an angle recomendation I am no help there. </div></div>

This ain't benchrest, and what was the reason they said it was the best? </div></div>
The one book I can find at the moment just says that is what the author found to be the most accurate. The only reason I posted it was to see what the smiths on here think about it. If there is something to that angle or similar ones being more accurate than a 90 I would want to hear about it.