!!!First Crowning Job!!!!

[bigngreen]

This is my first try at crowning a barrel. It looks better in person than the pic.

I set the barrel up in the head stock and dialed it in with a range rod till I had just a bump on the dial as I turned the barrel around. I faced it of and then set up to 11 degrees and cut the crown, the compound really was hard to feed smooth and I have one little ridge, the rifling is crisp and I just touched it with an abrasive to clean the edge from any burs. I made a small flat on the face so it wasn't sharp and beveled the edge which looks weird in the photo but it is very slight in reality.

It's not perfect but man am I jacked, I finally got the gutts up to start cutting, this crown looks way better than it had from the factory.

Give me a critique and pointers, please.

 

[dirtball]

As the man said in the movie "A bullet never lies" put a few through it and that will the best critique you can get.
Dave

 

[bigngreen]

I'm dying to go shoot it but I didn't grab my head space gauge so I need to get that done then we will be of to the range.
It can't be worse than what it was before, the face of the crown was upset at each land like they crowned it before pulling the rifling button though it.
It better be good cause I only have a half inch of barrel sticking out of chuck left to work with

 

[Fitch]

Ya sucked it up, flipped the switch, started cutting and got it done. Way to go! The first one is the hardest, it gets easier as you get better at getting the bore aligned with the lathe axis.

If you can find someone with a borescope, that's the way to look at a crown. This is the "before" picture of the crown on my brand new Savage 112 BVSS in 7mmMAG:

You can see how it looks sort of like it was nibbled on around the edges by metal mites. Not a crisp edge. This is the "after" picture:

I machine a recessed target crown with the plane of the crown at as close to "exactly" 90 degrees to the bore centerline as I can. I am able to use the power carriage feed out to where I use the compound (set at 45 degrees) to machine the bevel leaving a rim that protects the crown from damage during field use.

This isn't the same crown as the one in the other two pictures but it is the same style crown.

I don't do any beveling or anything else to create possible assymetrys where the plane of the crown meets the bore. I use a very sharp freshly honed HSS tool bit, flood the cut with oil, and run at about 250 rpm. Makes a nice crisp edge. I put a bronze bore brush thorugh the bore two or three times and that burnishes the edge.

I don't know this is the very best possible way to do it, not sure there is a best possible way truth be told, but it works for me.

Fitch

 

[bigbuck]

Good job bigngreen !!

BigBuck

 

[NesikaChad]

Well done! If this is something your planning to do often consider these:

Sandvik CXS-06T098-20-6215R grade 1025 Micro carbide boring bar ($35 ea)
Sandvik CXS-A0500-06 boring bar holder (around $100 bucks)

Once you do you'll feel inclined to wash your own mouth out with soap if you ever udder the words "High Speed Steel" again.


Recessed 11* hunter crown straight off the tool at 3000 rpm and .0015"/rev (700 SFM), no polishing:

 

[bigngreen]

Thanks for the encouragement guys.

My father in-law and I were discussing a bore scope. I have one but the quality is a little course, I use it to look into engines and transmissions. Could you guys though out any opinions on bore scopes, I have looked at the Hawkeye and choked at the cost, but it seem like an important to for diagnosing problems and checking work.

I used a carbide insert in the tool and the speed was up there, my father in-law set it. The tool was almost to large to get in and cut the taper without it touching the work with the bottom of the tool. I need to get that machinery hand book so I can try to set the speeds and tooling up right. It cut like butter, but the cross slide hasn't been used for a while so it was hard to not get a little bobble in the face. I would have wittled my barrel to a tooth pick I was having so much fun

I also checked out how accurately the carriage moved in relation to the center of the spindle to see if using the tool holder to chamber over the tweeked tail stock.
I figured out how to center up a ground rod using the method NesikaChad had posted to another site, got it dialed in perfect and then ran the carriage up and down about 3 in and there was no movement on the dial indicator so I'm going to order a #3MT holder for the tool post and a Bald Eagle reamer holder.

I need to get a better test indicator and base to get better resolution, any reasonable budget minded suggestions?? Everything I buy to work on my father in-laws lathe will transfer to mine when I get one bought so I want to get quality stuff but I don't need to pay for a name.

I got a better pic.

 

[coyotezapper]

Try a Q-Tip or a loose fitting patch pushed slowly out muzzle to check for burrs. if none it looks like you are good to go!!

 

[Eaglet]

Looks good to me man! Good work!

 

[trueblue]

Looks good, biggreen. Congrats on your new hobby.

 

[royinidaho]

bigngreeen,

Got a chuckle out of the toothpick part. Been there, done that, though not on a barrel.

How about a link to the link about centering a ground rod? (I'm sure that will help my lightening protection.) I'm at the beginning of the learning curve which is pretty steep for me. I never new something as small as .0005 could be so big.

 

[bigngreen]

I finally got the rifle all put back together and out to the range, the crown job cut my 1000yrd groups in half! I'm calling it good

I wish I had before pics, I wasn't thinking it was that bad but I think it was just kicking the bullet a little destablizing it as it broke from the muzzle.

 

[GNERGY]

I have a 25-06 that I had built back in the 70's for groundhog huntin with around 500 rounds thru it and have had trouble getting it to group lately. When it was new it would shoot 5 shot 1/2 inch groups all day, and that was with mixed lot used 30-06 military brass. My farthest groundhog kill was 550yds. I have always used a cleaning rod guide, but have also used some JB on it. So after all the reading I do on here, I thought why not recrown it. I have access to a lathe and a mill where I am working now. So I wrapped it up so it didn't look anything firearms related and took it in to work.
Indicated it in and cut a little off. It is a chrome moly barrel so I left a little blue ring around the outside.
It wouldn't shoot less than an inch at 100yds before the recrown.
It was over 95* in the shade with me trying to figure out a 1/2 inch of mirage ( orange square was dancing around ) I put 5 shots in 3/4 inch at 100yds.
So it looks like I will get some more good shooting out of the old 25-06.
Before, blurry pic

After recrown

Better goup at 100yds Sierra 90gr. HPBT less than an inch.

The old 25-06 made like the heavy benchrest/ varmint rifles. I made the stock from a big old piece of walnut that I bought that was for a fireplace mantle.

Tarey

 

[FEENIX]

I finally got the rifle all put back together and out to the range, the crown job cut my 1000yrd groups in half! I'm calling it good

I wish I had before pics, I wasn't thinking it was that bad but I think it was just kicking the bullet a little destablizing it as it broke from the muzzle.

For unbiased opinion, send it my way!

Seriously, excellent job.

Ed