How perfect should the crown be?

[1ShotKing]

Hey guys, had a look at the crown of my rifle and it seems a little rough. Maybe it's just me being too picky. Do you think it is bad enough to cause any ill-effects or am I just nitpicking here? I have done some machining at school, it just seems like a better finish wouldn't be too hard to achieve. Pictures aren't the greatest, apparently my phone doesn't like focusing that close. Thanks for any insight.

1ShotKing

http://i627.photobucket.com/albums/tt353/kevink400/Model%2012%20VLP%20DBM/photo32_zps32e62644.jpg
http://i627.photobucket.com/albums/tt353/kevink400/Model%2012%20VLP%20DBM/photo33_zpsdb5711a7.jpg

[BillPa]

Its tough looking at the pics, but the edge looks a little on the rough side. You might want to use a brass lap and compound to smooth it up.

Nit pick'n? Not really. I have the bad habit re-cutting the crown on every factory barrel before putting one round through it.

Bill

[stangfish]

What kind of tool did you use and which direction did you cut. In or out?

[Russell D]

Always cut crowns from inside out. It's should be done on a lathe, but you can use a piloted center.

What I do to tell if the crown will affect accuracy is take a Q-tip and go in the barrel and pull it towards the outside all the way around, if it catches and you see cotton hanging off the crown you have a burr.

[stangfish]

It looks like he went the other way.

[1ShotKing]

Russell, I tried the Q-tip trick. When going from inside of barrel to outside as you suggested, nothing is catching. However, if I take the Q-tip and just go around the outside of the bore I snag a little bit. Should this be an issue?

BillPa, I do not have a lap/compound to do that work. I am a little reluctant to have a smith tamper with the barrel unless absolutely necessary. I haven't had them do any work before, especially with a rifle with about 100 rounds through it.

[quickkillaught6]

1shot, one of my savage 10's look exactly like that as your pictures show. It is a parkerized rifle "" tacti-cool edition and yours appears from the photo to be a stainless gun that's been coated? None the less take a light and check out the first 2-3" of bore from the crown my sav-10 looks an awful lot like corrugated drain pipe and take me literally 2-3 days to clean from 40-50 rounds of shooting. I'll replace the whole mess later now I just wipe the outside with oil an clean the action. Might check it an see just how the rest of the barrel looks before dropping money for a crown job. Just my humble opinion.

[moonbogg]

I was paranoid about my new crown as well. It is not perfectly smooth either, similar to yours. After seeing the rifle shoots 1/2" groups with match ammo, I was less concerned. How does the rifle shoot?

[1ShotKing]

I made a trip to the range yesterday. Shot some groups trying to ease my mind. The picture on bottom is of the best two, 0.375" on the left and 0.423" on the right. The one on the left was a called flier, I knew I messed that one up. The reason for different point of impact is on the left is steel match 75 grain and 53 grain superformance v-max on the right. So it's quite accurate with both types. I also shot another 0.514" group with the steel match, top pic. I stuck one target to the other and ripped all that shoot and see stuff off. The group on the top was shot first, then made adjustments. I think it's fair to say it shoots sub-moa.

http://i627.photobucket.com/albums/tt353/kevink400/Model%2012%20VLP%20DBM/photo35_zps5c2d5ef6.jpg
http://i627.photobucket.com/albums/tt353/kevink400/Model%2012%20VLP%20DBM/photo34_zps7dbf0360.jpg

[Stockrex]

there was a thread nearly a year back which demonstrated that the crown is what it is just a crown and does not affect accuracy.

[rcshooter]

1. If you really want to see the shape of the crown you need a bore scope. If you can get one to use, it will magnify the bore and the entire inside of the barrel and chamber by 25x. They are a tool every serious target shooter needs.I use mine to check for copper fowling,
check the exact length of my chamber, and you can see any erosion of the rifle lands.

2. The crown is the last place that the bullet touches before it leaves the barrel.ANY marks or scratches in this area will change the shot to shot performance of the rifle.If you pull back a bronze brush over this area, chances are it has been scratched.I think that stainless steel is softer than other materials and it can be scratched very easily.If you can see any scratches or burrs with a bore scope, than it needs to re crowned. I think a slightly recessed crown is best .My gunsmith only charges $50.00 if you bring him the barrel.

I shoot bench rest for group size and I am really careful not to touch my crown with anything that is not going in the direction of a fired round.These are just my thoughts and other people may not be as careful but I have found that a few scratches on a crown can really open up a group size.