Newby barrel setup question.........

ultramagmed

ultramagmed

JKM
When dialing in a barrel, I understand how to dial in the chamber end off the lands and grooves with a test indicator, but how is the muzzle end indicated in with the outboard spider? Do you use the same method as the chamber end (test indicator on the lands and grooves)? I have read Mike Bryant's method with a Deltronic pin, but I am not even sure what that is. I have just barely got my lathe running and would like to practice on some take-off barrels, so any information would be helpful.

Thanks in advance,
JKM
 
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ultramagmed said:
When dialing in a barrel, I understand how to dial in the chamber end off the lands and grooves with a test indicator, but how is the muzzle end indicated in with the outboard spider? Do you use the same method as the chamber end (test indicator on the lands and grooves)? I have read Mike Bryant's method with a Deltronic pin, but I am not even sure what that is. I have just barely got my lathe running and would like to practice on some take-off barrels, so any information would be helpful.

Thanks in advance,
J.Kelly Medley
Click to expand...
The Deltronic pin, while ultra precise, is really overkill for barrel alignment if you use the dial indicator in-the-bore method for chamber end alignment. Here you are using the long probe of something like an Interapid dial indicator, or, predrilling the chamber body and using something like the Mitutoyo dial indicator.

A standard gage-pin set in the proper size range works just fine and is much less expensive. In the case of the 6MM bore use the M1 (0.061 - 0.250" -0.0002") size kit. http://cgi.ebay.com/190-M1-061-250-...14&_trkparms=72:1205|66:2|65:12|39:1|240:1318

As to indicating the bore, I suggest indicating on the lands when indicating the chamber end. This is where the reamer pilot rides. As to the crowning of the barrel, I'd indicate on the grooves since this is the most dominate surface as the bullet exits the bore, especially if you wish to put a small bevel (0.005" x 45 degrees or so) at the muzzle face/muzzle bore intersection.

Getting back to your original question, put a snug fitting pin, gage pin or Deltronic pin, in the muzzle bore that extends from the back of the headstock and use a regular dial indicator. Properly done this will put the muzzle bore within about 0.0005" while the chamber end is being machined.

PS were you living in Price, Utah in 1963 when the 5th Infantry (Mech) came through?
 
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ultramagmed said:
When dialing in a barrel, I understand how to dial in the chamber end off the lands and grooves with a test indicator, but how is the muzzle end indicated in with the outboard spider? Do you use the same method as the chamber end (test indicator on the lands and grooves)? I have read Mike Bryant's method with a Deltronic pin, but I am not even sure what that is. I have just barely got my lathe running and would like to practice on some take-off barrels, so any information would be helpful.

Thanks in advance,
J.Kelly Medley
Click to expand...

J,

PTG sells indicator rods that go in the muzzle/breech....they have a slight taper. I use them on the muzzle for final indication and breech, for initial indication, then I switch to direct indication with the interapid and long stylus.......setting the throat before machining, and recheck after machining and before reaming.

In the interest of continuous improvement of my procedure..I am considering getting the small bodied Mitutoyo indicator to use after drilling the chamber. Several people here have recommended that to me.

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=323819&t=11082005

Ben
 
Jerry,
They ain't enough pins there to do any good unless you are lucky. A set of Deltronic pins are in .0001 increments and I have a set of 25 per ea. caliber that I chamber. Do you have to have them? No, you can indicate the lands or grooves. They just make for a faster setup.
Butch
 
Butch Lambert said:
Jerry,
They ain't enough pins there to do any good unless you are lucky.


A set of Deltronic pins are in .0001 increments and I have a set of 25 per ea. caliber that I chamber. Do you have to have them? No, you can indicate the lands or grooves. They just make for a faster setup.
Butch
Click to expand...

Ain't enough pins? There is one for each 0.001" from 0.061" to 0.250", how many is that, 189.

Besides, 0.001" is close enough to use a pin and indicator for roughing in the alignment. If you use the pin's surface for final alignment you are just extending the error of any curvature of the bore.

This entire set of 189 pins is $27 and that set covers the 6mm, 22 cal, 20 cal and 17 cal. Deltronic pins 25 ea X $10 = $259....overkill. Buy sets of 25 Deltronics for each of the above calibers 4 X $259 = $1036.

Tennessee math vs. Texas math!!!


Sides' you ain't supposed to say ain't air ye??
 
Jerry I think we like to fuss. Where do you get your prices? I pay $105 for a set of 25 Deltronic pins. I guess the pins you use would get you within a couple thousandths. I indicate the throat with the indicator. If it is with in a couple tenths with the pins, it makes it much faster to indicate the grooves.
Butch
 
Butch Lambert said:
Jerry I think we like to fuss. Where do you get your prices? I pay $105 for a set of 25 Deltronic pins. I guess the pins you use would get you within a couple thousandths. I indicate the throat with the indicator. If it is with in a couple tenths with the pins, it makes it much faster to indicate the grooves.
Butch
Click to expand...
Nah, we ain't fussin, we'se discussin. Just covering the different options for the new folks.

Now, if I have a pin, 189 of them, for EACH 0.001" from 0.061" through 0.250" how am I going to get within a "couple thousandths"?

So, OK, 4 X $105 is still more than $27 ain't it? Some of this new math gets things all mixed up.

Gotta' go set up for the gun shot at Meadowview!!

http://www.vowguns.com/gunshowsnovember.html
 
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Whatever Jerry,
What does 4x$105 represent? You have 4 reamers or do 4 different calibers? I had rather have a first class set of guages.
Butch
 
Butch Lambert said:
Whatever Jerry,
What does 4x$105 represent?
Butch
Click to expand...

You said you had sets of Deltronic pins for several calibers at $105 per set. In my example, a M1 set of pins will do 4 calibers, 6MM, 22 cal, 20 cal and 17 cal, soooo, 4 X $105 = lemme, see = $420 doesn't it??

Now we are getting off topic and confusing the new guy.
 
Newby guy..............Here's the deal on the pins: Deltronic is not a type of gage pin, it is a brand name. They're good stuff, for sure, but are totally unnecessary. If you use a pin you pick up a point in space well beyond where the "business" ends of the barrel fall....while the important areas most likely are still running out slightly. You can pick up the lands and/or grooves where it counts, that is as close to where the throat and crown will be as you can reach......directly, with a test indicator. If you do go with pins, don't bother with (the common) class ZZ pins in .001" increments.......there won't be one in the set that fits snug in your bore (unless by coincidence), and 95% of them aren't even close to any barrel bore size...........those pin sets are for general measuring during manufacturing. Finally, if you're considering using pins because they (might) speed up the set-up process, try this instead: Indicate the outside of the barrel within a few thousandths first. Then move the indicators to the bore and finish indicating it in the rest of the way.

-Dave-:)
 
A good magnetic base will help get a ti setup on the backside of your lathe.
 
Dave,
I agree that you can do it without the pins. I do indicate the throat also, but it is a lot quicker to indicate a pin to get close. If you have a barrel that is out .005 or more on the OD to the ID, it is a real pain to start on the outside and then go to the inside with that much variance. When you reach into the throat only a couple tenths off it is a lot quicker to bring in. As you know a 6 groove does not always line up with your chuck jaws or cathead screws. If time is not of essence it doesn't matter.
Butch
 
Butch or Jerry,

I've been indicating my barrels off the grooves...does anyone indicate off the lands? Or does it matter?

In machining the barrel, the primary hole drilled is the lands? isn't it?

Ben
 
Bnhpr said:
Butch or Jerry,

I've been indicating my barrels off the grooves...does anyone indicate off the lands? Or does it matter?

In machining the barrel, the primary hole drilled is the lands? isn't it?

Ben
Click to expand...
Ben, on the chamber end I indicate off the lands since that is where the reamer pilot contacts. On the muzzle I indicate off the grooves and usually put a 0.005" x 45 bevel to break the sharp edge. On any beveled muzzle, the last place the bullet sees is the grooves.

Does indicating the grooves only or the lands only make a difference? I have only found one barrel over the years that the lands and grooves were not concentric, and that was by only 0.0002".

Does a sharp muzzle or a beveled muzzle, or a 11 degree muzzle matter? Some people like Ford trucks, some Chevy's, etc. A 45 degree break on the knife edge of the muzzle does make it more durable.

Accuracy. I don't know of anyone who has proved or disproved any particular muzzle geometry effect on accuracy.
 
Thanks.......

for all the replies guys. As I get more familiar with my lathe I'm sure I'll have more questions. Jerry, I was not yet born in 1963, but I'm sure there is someone in my family that would remember.
 
ultramagmed said:
Jerry, I was not yet born in 1963, but I'm sure there is someone in my family that would remember.
Click to expand...

We brought the entire 5th Infantry (Mech) through there on the way to Ft. Lewis, Washington. 2800 wheeled vehicles and 25,000 GI's. We sent our M48 tanks by rail.
 
JerrySharrett said:
We brought the entire 5th Infantry (Mech) through there on the way to Ft. Lewis, Washington. 2800 wheeled vehicles and 25,000 GI's. We sent our M48 tanks by rail.
Click to expand...

They'd surely remember if the M48's had have rolled down main street....
 
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