How bad is this crown?

[bookworm]

I've been trying to figure out why I can't get my AR-15 to shoot. Basically the best 5 shot group I can muster is around 3". I posted about it here a couple months ago:

http://www.longrangehunting.com/forums/f19/ar-15-accuracy-help-40596/

The more I read the more I see that "everyone" with an AR-15 seems to get pretty good accuracy (< 1 moa). I have access to a boresope at work, so I decided to take a closer look at the barrel to see if anything jumped out at me. I didn't find anything inside the barrel that stood out (although I'm no professional), but below is what the crown looks like. Now again I'm no gunsmith, but this crown looks like a rat chewed on it.

I don't know exactly what a "good" crown should look like, but can I assume that this is not it?

Do you think that this could be my source of inaccuracy?

 

[AJ Peacock]

I'd definitely get something done with that crown before I wasted any more components trying to figure it out.

I'd also buy some rat traps

AJ

 

[ICANHITHIMMAN]

A thats rough looking. You could sent it out or redo it your self with a drill, brass screw and a bit of lapping compound.

I will tell you what it cant hurt it.

 

[royinidaho]

Even if that crown didn't make any difference I couldn't live like that!

Speaking of rats, I think a trained beaver could do better.

As said above, it couldn't hurt to work it a bit.

 

[ss7mm]

I didn't know that you could crown a barrel with a cutting torch.

 

[ICANHITHIMMAN]

ss7mm

That last coment had me in stiches

 

[gamehauler]

WOW! thats incredible.

 

[kanem]

Bad, the crown should be sharp i never pull a brush back though a crown. Definatly get it redone. mk

 

[bookworm]

Ok - I think it is unanimous.

Any idea what a re-crown should cost me?

 

[royinidaho]

25 to 45 bucks. But a compassionate smith would do it just for the good will.

 

[Crane]

I would try to barely "kiss" it with a lightly abrasive ball and a dremel on slow speed; or even hand turned. I wouldn't worry too much about messing it up.

 

[J E Custom]

All I can say is wow !!!!!!!!!

Have your smith re crown with a 11o degree cutter and "DO NOT CHAMPHER THE BORE''
you clean from the receiver end anyway and a sharp exit edge seems to work best for
me.

And as Kanem said pull the brush from breach to crown and not backwards unless you
use a swab instead of a brush.

J E CUSTOM

 

[TnTom]

just curious who did that work?

 

[nitrousmudbogger]

Wow that is ****! get it redone. Im w JE Custom on the 11degree. It looks like you are going to have to bring it back at least 1/4". The rifleing and everything look horrible. If that doesnt work who ever took pride in the crown prolly did that good on the rest of it and Id use it as a jack handle and get a new one.