What's your favorite way to dial in a barrel?

[LVLAaron]

Well, I have chucked a 30 inch Krieger and let it hang out and measured the runout on the OD
it was only .008" way out at the end, they are very straight.
So yeah, another reaon I like Krieger
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I have also dialed in Bartlein ID , then measured the OD for a comparison to see how close the OD was to the ID
It was within .0003" - That was a Carbon Wrapped as well
concentric enough for me to even dial in on the OD if a guy wanted to
(Way better than guys that are chambering with a 3 jaw)
I mean I like to get things to that .0001" but in a pinch, such as a varmint or hunting rifle
.0003" is plenty accurate.
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But are you suggesting the bore will wander much just within cartridge length on a Krieger??
Even if both ends are dialed in?

Different strokes. I paid a lot for things that measure to zero. I want to take every advantage of that I possibly can.

 

[ELR LVR]

Different strokes. I paid a lot for things that measure to zero. I want to take every advantage of that I possibly can.

Well let me ask you this,
If I am - not preboring
And I am letting the piloted reamer, guide itself through the bore from start to finish...........
All my chambers have come out concentric and true to reamer size (Not oversize chamber)
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What am I missing?
Other than it just takes longer.
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When reaming, you can actually see if anything is off because the end of the reamer will tell the tale because any deflection will be more pronounced at the tail end of the reamer. (It will wobble)
if the reamer itself stays straight, that is also easy to see and feel
I hold the reamer by hand with a tool as I push.... so I can feel how everything is cutting as well as gauge and see and feel any deflection
(I'm not a high volume guy, so my old school methods I admit take more time than other methods)

 

[LVLAaron]

Never used a pusher, one day I'll get around to testing it. Depending how you're pushing, you could basically have a 3 axis float and it not matter much, since it'd be following the bore like you said.

 

[luckyshot52]

The chamber needs to be concentric, both axial and radially! This assures bullet will start on centerline. Same procedure needs to be done when doing the crown. So bullet exits on centerline. This way the bore in between doesn’t matter. Also assuming the ID is concentric to centerline is a mistake.

 

[SKWERLZ]

So...
To do that with a 2-3/4" stylus (I use the same indicator), I'm guessing you indicate as far as you can reach to get "close", drill/bore deep enough to get the end of the indicator into the breech, dial your two points, then skim again with a boring bar to true the hole to re-positioned barrel?

Yep.
On 6 BR or even my 7 saum I reach everything I need, on my 338 drill a 1/2x1/2 pocket for reaching in.

 

[Judd]

These posts always get spirited but with an open mind I typically learn something…or something new to try.

I’ve done both dialing the throat and muzzle and dialing the throat and just in front of the throat, drilling, boring or running the reamer the whole way. What I’ve found is, if you spend the time getting it straight then you’ll likely have a really good chance of it being straight when you finish.

I like to switch things up so it isn’t the same ole same ole…lately I’ve been indicating both ends, drilling and boring. Before I traded building them for shooting them, I’ve had my donkey kicked by both methods of indicating…I’m starting to believe that we can’t shoot the difference, but they have to be straight.

 

[V35]

I like to switch things up so it isn’t the same ole same ole…lately I’ve been indicating both ends, drilling and boring. Before I traded building them for shooting them, I’ve had my donkey kicked by both methods of indicating…I’m starting to believe that we can’t shoot the difference, but they have to be straight.

I have always said that part about shooting the difference in a hunting rifle for sure. I chambered in a steady on my 22” Kingston for a long time before I bought a little 13” just for rifles, they all turned out great. These days I chamber in the headstock, and I just dial the throat with the Interapid.

 

[DShortt]

Never used a pusher, one day I'll get around to testing it. Depending how you're pushing, you could basically have a 3 axis float and it not matter much, since it'd be following the bore like you said.

This is why I like a 3 - axis pusher.

It's been suggested in another thread that if the bore does not run true for at least the reamer and pilot length, it could cause problems.

I have to wonder what barrel that fellow is using to be concerned about that.

 

[Cloudrepair]

I think it is three points you can dial in because i can always dial in the throat, about a inch forward of that to about .0002 and the muzzle then when i crown i dial in the muzzle one point on the reamed hole and about a half inch or so ahead of my first point on my muzzle then i always know all is good and i dont have to even think about all the trouble of timing or how that can go wrong.
I do drill and bore the hole im going to ream also and check with the indicator many ti.es and after work is done.

 

[ELR LVR]

This is why I like a 3 - axis pusher.

It's been suggested in another thread that if the bore does not run true for at least the reamer and pilot length, it could cause problems.

--- I have to wonder what barrel that fellow is using to be concerned about that.---

My thoughts exactly

 

[LVLAaron]

Perspective matters....

Does 2 tenths matter? Maybe. Does 5? Maybe. If I'm building something for myself, I'm willing to take risks (shortcuts) , knowing if I'm unhappy I can just take some time and change it.

I don't clock barrels for myself unless I know I need to. (I don't care if I need to adjust windage a couple clicks for a new barrel) - But the person I'm doing a chamber for, is excited that they didn't have to change windage (much) between barrels. To them it means I pay attention to detail, and I do. I might be paying attention to details they can't measure, but it's important (to me) to do a little extra to make the end user happy. I think most people are excited and optimistic to get a new barrel. I will do whatever I can to make sure it's a positive experience.

Like Dave always says. Don't make the phone ring. (Unless it's to show me targets and groups, those are good calls!)

 

[tobnpr]

Well let me ask you this,
If I am - not preboring
And I am letting the piloted reamer, guide itself through the bore from start to finish...........
All my chambers have come out concentric and true to reamer size (Not oversize chamber)
--------------------------
What am I missing?
Other than it just takes longer.
--------------------------
When reaming, you can actually see if anything is off because the end of the reamer will tell the tale because any deflection will be more pronounced at the tail end of the reamer. (It will wobble)
if the reamer itself stays straight, that is also easy to see and feel
I hold the reamer by hand with a tool as I push.... so I can feel how everything is cutting as well as gauge and see and feel any deflection
(I'm not a high volume guy, so my old school methods I admit take more time than other methods)

Keep in mind that a piloted reamer has clearances- pilot to bore (couple of tenths), as well as pilot to reamer with removable pilots- which will stack.

If one dials the throat and uses a trued hole to start/guide the reamer, a piloted reamer may or may not be perfectly concentric to the throat area as it enters the bore

 

[LVLAaron]

Keep in mind that a piloted reamer has clearances- pilot to bore (couple of tenths), as well as pilot to reamer with removable pilots- which will stack.

If one dials the throat and uses a trued hole to start/guide the reamer, a piloted reamer may or may not be perfectly concentric to the throat area

If we're doing all this pre-bore work; save the trouble and skip the pilot.

 

[tobnpr]

If we're doing all this pre-bore work; save the trouble and skip the pilot.

No doubt .
Just a nagging, completely unjustified terror engulfs me every time I think about doing just that before I start running the reamer in and I can't bring myself to remove the pilot lol.

I need to get over it, for no other reason than increasing flow rate. Next time...

 

[LVLAaron]

No doubt .
Just a nagging, completely unjustified terror engulfs me every time I think about doing just that before I start running the reamer in and I can't bring myself to remove the pilot lol.

I need to get over it, for no other reason than increasing flow rate. Next time...

If everything is straight, the pilot isn't doing anything. If the pilot is doing something, something is wrong. Of course a 5 groove barrel changes all of that

 

[ELR LVR]

If everything is straight, the pilot isn't doing anything.

View attachment 1648934

Thats what I believe as well, the reamer should keep itself centered if all flutes are cutting
the live pilot makes me feel warm and fuzzy though

 

[boltfluter]

From a machinist/machining point of view, a reamer is designed to finish a hole, not drill a hole. A piloted core drill ground about .015 to .020 undersized would be the way I would approach this job, and I would be off to the races. So to speak. Lol. Many ways to do this job and end up with a very nice chamber. Keep the answers coming guys. Great thread.
Paul

 

[LVLAaron]

From a machinist/machining point of view, a reamer is designed to finish a hole, not drill a hole. A piloted core drill ground about .015 to .020 undersized would be the way I would approach this job, and I would be off to the races. So to speak. Lol. Many ways to do this job and end up with a very nice chamber. Keep the answers coming guys. Great thread.
Paul

I LOVE using JGS twist "core drills"

 

[FireMedic]

If everything is straight, the pilot isn't doing anything. If the pilot is doing something, something is wrong. Of course a 5 groove barrel changes all of that

View attachment 1648934

I’ve seen some reamers need some support with a bushing in traditional 6 groove barrels. They are typically long freebores in small calibers….The reamers that will flex the most.

I’ve only experienced this with some brux barrels that have some pretty angled ramps on the sides of the lands. I could see the deflection in the throat cut with the bore scope. The bushing fixed it with nice straight cuts. Most of the time though, no bushing is needed. I do leave an undersized one on there most of the time.

You’re right, the 5 grooves needs a well fitted bushing or a 5 flute reamer. I don’t like that a tight bushing will leave marks on the land tops though. Not that it affects much, but we are back to the phone ringing thing again. Lol

 

[ELR LVR]

I LOVE using JGS twist "core drills"

I just looked for these, didn't know about them
All list as out of stock?
Are they not making them any more because that would be a good idea.
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Traditionally some guys would use a roughing reamer
Although when I first began chambering many more experienced people said
"for the low volume guy and the amount of chambers done per year"
Even a roughing reamer isn't necessary
Fully chambering with the finish reamer all the way With no ill effects to the finishing reamer
So I tried it that way and sure enough
no ill effects, my reamers still cut as day one
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For a machinist in the main course of business of doing chambers I would do things a little differently and have more tooling for preboring etc.
But - if you weigh in the added cost of the extra tooling, roughing reamers, prebore drills etc
it's just as easy to get a new reamer as is it to have a roughing reamer also.
I've read of guys doing dozens of chambers on one reamer if its taken care of right
Flutes cleared often enough.... oiled enough etc.
So I took all those old timers advices, and don't get too reamer happy and clear the flutes often so as to not dull or chip any flutes.
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So I could roughing reamer it then finish reamer it
or just finish reamer it and be done, with the mindset if my reamer ever goes dull I'll have to buy another.
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I don't like the idea of predrilling for myself because, the drill has to be held in a chuck by the tailstock
which the tailstock is always a little high (Mine is .003" high) and is never on centerline
so the drill bit will flex, or possibly want to wander
When pushing the finish reamer, it fully floats and keeps itself straight from start to finish
To me, that is just the easiest way for me while buying only the necessary tooling for doing work for oneself
All the Aloris, and carbide and indicators and holders cost enough
I try to keep my tooling costs practical for whats needed without getting too happy about buying stuff I dont REALLY REALLY NEED ya know.
Because I have worked at shops that had all the cool stuff a guy drools over and wants for himself
but...........like I said, I don't machine as my main course of business anymore, just for me.
(I might do one or two for a friend once or twice a year after they shoot mine and want one)
And try to keep it practical as my chambers come out very nice and concentric and follow the bore.
Which in my mind, is the ultimate goal anyway. The targets seem to prove it.
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So am not arguing with you guys that chamber a lot
Just pointing out, for the home hobbyist
.....it can be done nicely and accurately with a piloted finish reamer and some good carbide tooling
I also try to cheat as much as possible to do something cheap and easy
I WANT a Baldor 500, but found I can do the same thing with 20 dollar diamond lapidary discs to sharpen my carbide. Inspect with a Jewelers loupe and touch up or radius with a fine hand held diamond hone.
You'd be surprised what a machinst can do by hand sharpening carbide by eye, I bet many of you guys know what I mean when you have worked with small tolerances for years.
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Close up pic of a 22-250 finish reamer thats done a few chambers and still looks like new