Terminology

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USP45usp

Moderator
I have a question on terms... what exactly is the crown? Is that the rounded area at the muzzle of the gun?

How much does it affect accuracy?

And how do you create a crown?

The reason that I am asking is that I have a "sporterized" 30-40 Krag (and NO, I didn't do it) and the barrel looks like it was just chopped off. No rounded thing or such.

But it seems to hit POA very well but it could be tightened up (the groups).

Thanks in advance.

Wayne
 
There are various shapes for a crown but the critical thing is that the muzzle be perfectly square with the barrel.There also must be no dings or other damage at the crown/bore edge.
 
I believe Brownells sells a crown cutter for a low price. Seems i read a magazine article about it and it was a pretty simple job
 
RallyHound,

Thanks, I'll look into it. I would love to get better groups with the 30-40, plan of using it as my hunting gun.

Wayne
 
re-crown

Dear Sir:
A "crown" at the muzzle is the most importand area of a firearms barrel!
There are 11 degree crowns, recessed crowns of various shapes, and target crowns just to mention a few.
The BEST crown (since all bores are , or may not be, concentric with the outside of the barrel) are target, recessed crowns. There is a reason for this; if, as is many times the case you do an 11 degree crown and the bore is not centered in the barrel stock you will have a gas release on just one side of the bullet a nanosecond prior to exit. With a recessed "90 degree" crown that makes no difference (this is predicated on having the bbl' mounted in the lathe perfectly) :) .
Really, the hand crown tools worl VERY well due to what I've said.
 
30/40 Krag

You'll find it to be an excellent hunting round inless your going for long range flat shooting. I'd have a good gunsmith look it over really well because the Krag has only one lug on the action. Smooth as butter, wondetful rifle. If you reload, don't push the max. Find a midrange load which gives good accuracy.
 
Thanks all.

I don't know how well the barrel was cut but I'll probably get the hand tool and try it (and if I mess up then off to the gunsmith I go).

I just like the smooth action of the Krag. And I love the trapdoor loading feature :).

Wayne
 
Harry Bonar did a good job of explaining the different types of crowns, but remember that the ONLY purpose of a crown is to protect that very critical area where the bore of the barrel ends. If it is dinged up or uneven, the rifle will not shoot accurately. The reason is that as the bullet exits from an uneven muzzle, gas escaping from the shorter side will tip the bullet in an unpredictable manner.

When a barrel has been cut with a saw, it is first necessary to true up the muzzle before even beginning to cut a crown. And it is very difficult to true a muzzle any way but in a lathe. I don't say it can't be done with one of those crowning tools, but I would not have high hopes if the end of the barrel is not true to begin with.

Jim
 
Thanks Jim,

I'll take it out to see where the POA/I is and if I can live with it. If I can't then I'll find a Smith with a full sized shop.

Thanks all again.

Wayne
 
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