What I learned about dialing in a barrel

[hoz53]

No reason to do any less than your own personal "perfect". Whether or not a shooter can make use of it or not doesnt matter. I 100% believe good work produces more good barrels than ok work. A hummer can make up for a lot, but you have to look at consistency over time.

for me doing my own work there is no reason not to do the best i can. Thats why i continually try to learn more about it. Costs the same and doesnt take much more time either. Now if I just need an AR15 barrel for some mag dumping that mite be a little different.

 

[hoz53]

Someday I'll get around to mounting this all somehow (and someday I'll sweep up all those chips), but for now, it all works great. This is all there is to it:

A dam made from a small chunk of oil-absorbing material handles the tramp-oil:

looks like a simple set up to me. how do you regulate the pressure and how do you couple the coupling to the barrel. Thanks

 

[Stan Taylor]

sounds reasonable to me. So far ive just used a pumper type oil can for everything i do on the lathe. thanks

Here is pics of pump an recovery system on our machine the muzzle end goes up against grommet in machine to prevent spillage an good oil flow.

 

[GenePoole]

looks like a simple set up to me. how do you regulate the pressure and how do you couple the coupling to the barrel. Thanks

Maybe I replied to the wrong thread. I posted somewhere here (or in another thread) my Dueblin rotary union. Someone asked about the rest of the system.

It's a carbonator pump used from ebay. I replaced the spring in the bypass regulator with a weaker spring and adjusted it to about 15 psi against a shutoff head. The pump is capable of like a 150 psi shutoff head. The bypass regulator is just a spring and plunger under a cap nut on the right side and pointing down at about 20° (you can just make it out in the picture).

 

[hoz53]

Maybe I replied to the wrong thread. I posted somewhere here (or in another thread) my Dueblin rotary union. Someone asked about the rest of the system.

It's a carbonator pump used from ebay. I replaced the spring in the bypass regulator with a weaker spring and adjusted it to about 15 psi against a shutoff head. The pump is capable of like a 150 psi shutoff head. The bypass regulator is just a spring and plunger under a cap nut on the right side and pointing down at about 20° (you can just make it out in the picture).

Thanks

 

[hoz53]

Here is pics of pump an recovery system on our machine the muzzle end goes up against grommet in machine to prevent spillage an good oil flow.

thanks stan

 

[Papa Charlie]

i thought that way for awhile. there are so many excellent barrel fitters in the business that dont do it that way though that expanded my thinking on it. there are lots in the business that use the pilot all the way mode to. I sure havent done enough to form a concrete opinion on it. One thing Ive been thinking though is as youre finishing the chamber that bushing is in bore that wont get cut away. i had a reamer making a squeek last one i did and i couldnt figure it out. I dont think it would take much sideways pressure to damage the bore in that area. somethin to think about.

You bring up a good point. Maybe it makes sense before the pilot reaches the final bore, to remove it. At this point one would assume that the reamer has already established its path and is sufficiently supported by the reamer body. Completely guessing at this, better to think about this now, then after your start cutting on an expensive barrel.

 

[hoz53]

so

You bring up a good point. Maybe it makes sense before the pilot reaches the final bore, to remove it. At this point one would assume that the reamer has already established its path and is sufficiently supported by the reamer body. Completely guessing at this, better to think about this now, then after your start cutting on an expensive barrel.

some great barrel fitters never use a bushing- solid pilot reamers are cheaper- i wonder about getting them with a smaller pilot

 

[Papa Charlie]

so
some great barrel fitters never use a bushing- solid pilot reamers are cheaper- i wonder about getting them with a smaller pilot

I too have read here on AS the same thing. Don't know if they just started that way maybe before pilots came out, or they have developed a skill level and technique over the years or just the way they learned.

Starting out, don't know which is the best way to go. I don't plan on doing this work for anyone but myself and so it is highly likely that I will do many barrels. Making my learning curve a long one to get to the master smiths you are referring to.

I wonder if there are some inherent issue between solid pilots and bushings?

 

[hoz53]

I too have read here on AS the same thing. Don't know if they just started that way maybe before pilots came out, or they have developed a skill level and technique over the years or just the way they learned.

Starting out, don't know which is the best way to go. I don't plan on doing this work for anyone but myself and so it is highly likely that I will do many barrels. Making my learning curve a long one to get to the master smiths you are referring to.

I wonder if there are some inherent issue between solid pilots and bushings?

ive been through that same thing- it all comes down to deciding what u think is best for you. bushings are used because bores are not all the same exact dia.

 

[INTJ]

Also, it's not that big of deal what technique you use. The key is to get good at doing it your way and become consistent. They you can start tweaking your methods and see what makes more accurate barrels and what doesn't matter.

 

[Papa Charlie]

Also, it's not that big of deal what technique you use. The key is to get good at doing it your way and become consistent. They you can start tweaking your methods and see what makes more accurate barrels and what doesn't matter.

I agree 100%, but this works better when you are doing it a lot. For the average shooter, how many times a year or over two or three years will they chamber a barrel. That makes for a horribly long learning curve. So to steepen the slope, one must go through the 1000 questions before we start cutting on a barrel.

At least for me this is true.

 

[hoz53]

I agree 100%, but this works better when you are doing it a lot. For the average shooter, how many times a year or over two or three years will they chamber a barrel. That makes for a horribly long learning curve. So to steepen the slope, one must go through the 1000 questions before we start cutting on a barrel.

At least for me this is true.

Thats what ive tried to do to. At some point you learn enough that all thats left is deciding which way you want to do it. Or where you want to start. So much of the info we get is a bit conflicting because different people do it different ways. a little experimenting is hard to avoid if you want to really find what works for you. Id recommend buying some strait taper barrels to begin with. That way you can cut them off alot of times for practice if you need to. I actually got some used barrels but dont waste your time with those. Buy new barrels and eliminate a variable. My first barrel was a cheap GM i chambered in 22br - it shot great and that was very satisfying. Reamers usually last for alot of barrels so you can practice alot. Getting a piece of aluminum 1 1/4 round stock to practice and its easier on the tooling. check your chambers for how concentric they come out and go shoot them. If they dont shoot good cut it off and try a different way. You can do alot of chambers on a few barrels. - if you just want a few good barrels on a few rifles you may be better off just having someone else chamber your barrels. Its a whole lot cheaper and if you look around you can find quality work in very reasonable time frames.

 

[INTJ]

I agree with @hoz53. And I bet I can speak for both him and me and say we get where you are at because we are just past that ourselves.

I too researched, asked questions, and thought through how I was going to do this. I got a hands on demo from a gunsmith friend. Then I picked a method and dove in. I chambered my first barrel about a year and and have done all of six since then.

The first one was rechamber and it came out good. I messed up the second one-- twice, and gave it away to someone who didn't mind making it into a 27" 6 BRA BR barrel.

The third one I messed up and made the chamber oversized, but that barrel shoots very well in LR BR. I'll probably cut off and rechamber to fix the chamber and shoot it some more.

My next barrel, a 300 WSM LR BR barrel is shooting well. My most recent 6 BRA barrel still needs some more tuning.

My last one was a 33-28 Nosler and it is shooting well.

I am getting faster each time. Dialing in a barrel now takes 1/6th the time it used to.

 

[LC Tikka]

Is spider screw position important?
Most spider plates have screws at 90° to barrel axis, if the screw tip is not an ideal shape, tightening would impose a heavy side load. Therefore if the screws were inclined square to the barrel taper/surface or close to it for ease of section, the screw loads on the barrel would be more uniform. Also a bridge pad on the screw end would improve contact stability on the barrel.
All been done before?

 

[hoz53]

My normal disclaimer. I am a permanent amateur newby when it comes to chambering barrels. While I am getting picky about doing things my way, I make no claim my way is remotely the best way....though I am making good shooting rifles.

I discovered that when dialing in a barrel, the throat area needs to be at the pivot point in the chuck jaws. I use 1/16" aluminum shims on the chuck jaws. Here is how I discovered that.

Last week I chambered my first wildcat, a 33-28 Nosler on a New M-70. (Looks like it's going to be a shooter.) It is the first time I have chambered a #4 barrel. All my others have been HV contour. A number four is very bendy......

It was also the longest case I had tried to chamber at 2.5". The other ones I chambered were in 6 BRA and 300 WSM.

I like to dial the throat area to zero, get the breech end as close to zero as I can, and I let the muzzle run out. This is in a 4-jaw, through the headstock, with a spider, and a PM 1340 GT lathe. I use aluminum shims on the chuck jaws and Grizzly rods with a snug pilot to dial in. (I'll double check with an Interapid long reach off the lands.) I use .0002" smaller pilot on the reamer than what I dialed in with.

I had about 2" of the breech sticking out of the chuck. As I was trying to dial in I could get the throat (2.8") to zero runout, but whenever I would use the spider to adjust the breech I would get a lot of runout when I'd recheck the throat. I'd also have a lot of muzzle runout, like .100". I spent hours going back and forth on this. I never had this much trouble with my 6 BRA or 300 WSM.

So I started thinking about it very intently (that's an INTJ thing) and realized the issue. It was not going to be possible for me to dial in the barrel this way. Since I had only 2" of barrel outside the chuck, every time I'd adjust the spider BOTH the breech and throat were moving.

So I dialed the area at the pivot point of the chuck shims to zero, then I dialed the breech to near zero. I checked the throat area and it was maybe .0003". Since this was a hunting rifle in a heavy recoiling cartridge, and I have a floating reamer holder that moves radially AND axially, I called it good. Also, the muzzle only had about .012" of runout.

Going forward I'll make sure the throat area is in the pivot point whenever I can. When I can't, I'll do it like I described above. My only reservation is I'd rather not have 3" of barrel sticking out of the chuck, but since I recheck dial in right before chambering I should be okay. Also, since I am using a chuck vs an inboard spider I do have better grip on the barrel.

I also discovered a better way to initially set up the barrel. I leave the spider loose and then get the outside of the barrel at the chuck to within .001". I then indicate the outside of the muzzle to within .001" with the spider. That makes the barrel fairly concentric with the lathe as I start the dialing in the bore.

For all you real gunsmiths I am sure all this is old hat, but to hobbyists like @hoz53 and I, it often helps to have an amateur describe what they learned so we can think through things you guys learned and forgot decades ago.....

Wow INTJ— i just read through this several year old thread you started and was reminded that there is a bunch of really good stuff in it. Some of it from some of the best out there.
There were answers to things i had wondered about for awhile. Im chambering the best barrel Ive ever owned (should be) right now so we’ll see if ive learned anything soon.
Thanks- hope the job is going well

 

[INTJ]

Wow INTJ— i just read through this several year old thread you started and was reminded that there is a bunch of really good stuff in it. Some of it from some of the best out there.
There were answers to things i had wondered about for awhile. Im chambering the best barrel Ive ever owned (should be) right now so we’ll see if ive learned anything soon.
Thanks- hope the job is going well

Well I am now shop manager. I still have to chamber barrels but we have the second lathe in place and hope to get it up and running very soon. We also hope to get the second lathe operator up to speed soon as well.

 

[butchlambert]

Is spider screw position important?
Most spider plates have screws at 90° to barrel axis, if the screw tip is not an ideal shape, tightening would impose a heavy side load. Therefore if the screws were inclined square to the barrel taper/surface or close to it for ease of section, the screw loads on the barrel would be more uniform. Also a bridge pad on the screw end would improve contact stability on the barrel.
All been done before?

Use your search function and you will find several post on this.

 

[WSnyder]

Also a bridge pad on the screw end would improve contact stability on the barrel.
All been done before?

Yes, all have been done before.

 

[ronsatspokane]

Well I am now shop manager. I still have to chamber barrels but we have the second lathe in place and hope to get it up and running very soon. We also hope to get the second lathe operator up to speed soon as well.

Just so you know, you are a bad influence. I just ordered one of the inside spiders off Grizzly. Going to give it a try versus the 4 jaw and Alu tabs.