Author Topic: Bad Crown (Read 865 times)

Nova · « **on:** January 23, 2005, 08:53:32 AM »

Well I'm pretty much snowed in today so I've been doing a lot of posting...haha. I was also looking over my Handi and noticed something with the crown of the barrel. I have only shot about 60 rds through this 223 and have had marginal accuracy. I haven't been too concerned because I didn't do any bore polishing. My buddy just got the same rifle and seems to be gettin better accuracy with a few less rds down range. The crown of my barrel does not seem to be perfectly round (there are a few flat spots) Is this normal? Could this be causing the not so good accuracy and frequent flyers? I haven't used a cleaning rod more than once or twice, so i wouldn't think that would have caused it. Any thoughts?

Thanks

BTW--where can i get some JB Bore Polish?

ebonitekid767 · « **Reply #1 on:** January 23, 2005, 08:57:43 AM »

i have noticed the same thing with my heavy barrel .223......only 15 rounds through it.....not sure what the problem is.accuracy seems fine.

jeff223 · « **Reply #2 on:** January 23, 2005, 09:23:32 AM »

a new crown sure cant hurt anything.i would have a smith at least look at the crown.i had mine done and this is how it looks compaired to the factory crown.the accuracy sure got better after the new crown.

a new crown will run you about $30.00

quickdtoo · « **Reply #3 on:** January 23, 2005, 09:56:30 AM »

You can clean up that crown with a little valve grinding compound and either a ball bearing that will fit in the recess of the target crown or a small carriage bolt head. I've done a couple and lots of shooters at RFC have done it.

http://www272.pair.com/stevewag/muzzle/mz.html

while99 · « **Reply #4 on:** January 23, 2005, 12:48:12 PM »

You can also buy a crowning tool from Brownell's that has a t-handle, a properly-sized spud to fit into the bore, and it will cut an eleven degree "Fort Benning" crown. Brownell's also sells regular crowning tools that will require a lathe to use.

quickdtoo · « **Reply #5 on:** January 23, 2005, 01:18:56 PM »

The procedure I described is for touching up a crown that has some minor flaws as Nova described. To buy and use the proper crowning tools yourself, cost is substantially more than a crown job done by a smith. IIRC, the tool is $65 and pilots are extra per caliber.

http://riflestocks.tripod.com/targetcrown.html

Nova · « **Reply #6 on:** January 23, 2005, 03:42:32 PM »

Ok, I may have used some incorrect terminology when describing my situation. When I said the crown was uneven, I was referring to the actual bore which does not seem perfectly round at the end of the barrel. When i looked at the pictures of the barrel that was used in that demonstration, it does not look perfectly round either. Is this normal? Maybe I'm just subconsciencely looking for an excuse to cover up my shortcummings at the bench.

Thanks

Brett · « **Reply #7 on:** January 23, 2005, 04:09:09 PM »

Looking straight down at the muzzle the inside edge of the barrel should not look perfectly round like the letter O you should see the high and low areas where the lands & grooves terminate at the muzzle.

Nova · « **Reply #8 on:** January 23, 2005, 04:58:46 PM »

Well I guess everything is normal. Thanks for the help guys and sorry if I wasted any time. I guess now I'm just gonna have to go buy some Winchesters and get out to the range..... :wink: If I get some of that JB bore polish, what is the process of polishing without causing barrel damage? Forgive me if this has already been discussed (which i'm sure it has been).

quickdtoo · « **Reply #9 on:** January 23, 2005, 05:13:42 PM »

I use Varmint Al's method without the moly bullets. A tight bore mop or a patch and jag will work fine. This will not damage a barrrel as long as you're careful at the throat and crown, wipe the rod frequently...or use a patchworm.

http://www.varmintal.com/ashot.htm#Break

www.patchworm.com

Donaldo · « **Reply #10 on:** January 23, 2005, 05:33:58 PM »

If you are going to polish the bore like Quick said take a fired case from your rifle. Deprime it and either cut the head off or drill out the base with at least a 1/4" drill. Insert this case in the chamber before you start the swabbing with the mop. That way it protects the throat and chamber from the rod.

fish280 · « **Reply #11 on:** January 24, 2005, 01:37:29 AM »

i've used run-of-the-mill non-hardened carriage bolts for years. never a problem. just be judicious and run the drill on low speed, forward and reverse. you can check whether the crown is even by tapping the front of a bullet into the muzzle a little ways, then pulling it and seeing if land/groove impressions are even all the way around. in fact, do that first to see if it really is a faulty crown. if it's way bad, it'll show.

quickdtoo · « **Reply #12 on:** February 06, 2005, 08:02:54 AM »

Just found this at Varmint Al's web site...

http://www.varmintal.com/ashot.htm#Kissed

Deadeye47 · « **Reply #13 on:** February 06, 2005, 08:21:18 AM »

man...that is what is known as a long page!! :shock: :-D

quickdtoo · « **Reply #14 on:** February 06, 2005, 08:45:53 AM »

Yup, he's got a lot of info on his site, I keep finding new stuff there all the time cuz he just keeps adding stuff! I just downloaded his recoil calculator which is on the same page.... :wink: