Indicating Barrel

[macardoso]

Long Island indicator links to Amazon as the preferred supplier.

Amazon.com

MSC also looks to carry them

 

[pontiac428]

How are you indicating your barrel, off of the bore, the exterior, or using a range rod? Are you centering at the muzzle only, or are you indicating along the bore at two spots? Runout can occur as parallel/eccentric or as taper/wobble. The only way I know how to measure both is with a range rod stuck in the bore. Same condition exists when doing receivers and bolts. It's tough to measure directly, so you need to make a few tools to set up a barrel job. Cue a plug for Hinnant's book here.

 

[stupoty]

Is there a place that rebuilds indicators? Also if I am going to spend $300 on one, I want to make sure i am not purchasing a fake.

You can check a second hand one with gauge blocks or even some random material you can measure with a micrometer.

but if you have the cash for a new one it does give you a head start on getting going.

Stu

 

[higgite]

Long Island indicator co is a well known one. Not cheap but has a great reputation. Won’t work on import stuff, only quality brands.

Professional repair service for test indicators, micrometers and other precision gages and small hand tools

Repair service for Interapid test indicators and other precision measuring gages by Brown & Sharpe and Mitutoyo.

www.longislandindicator.com

any time you buy used or cheap, you risk fakes. If you’re buying new, I’d buy from an authorized distributor.

Not working on import stuff must be a new thing with them. They repaired my Mitutoyo test indicator 3 years ago.

Tom

 

[macardoso]

Not working on import stuff must be a new thing with them. They repaired my Mitutoyo test indicator 3 years ago.

Tom

I'll correct - not working on "cheap" import stuff.

They have a whole page on what they will and won't repair.

 

[seasicksteve]

OP I love Interapid indicators and if you dont mind throwing down for one it is one of the best out out there. I will submit this for your consideration Mitutoyo 513 This one works quit well and is less $$. You can add a longer contact point if you want, it will however reduce the resolution. I use one and have tailored my methods so that I can read directly off the lands and grooves. I remove some material from the chamber and can insert the cylindrical portion of the indicator into the barrel and extend the useful reach. I can do shorter cartridges without extending the contact point

 

[Earl]

Here are the indicators that I use. The Brown and Sharp 50 millionths indicator I use for centering the bore in the set tru chuck. I chamber thru the headstock. I have the jaws cut (EDM'd) so the muzzle is as close to the face of the chuck as I can get it. I true the chuck with the indicator is as far as it will go. Then I retract the indicator until the point is just in the barrel 50 thou or so. Then I use the spider at the muzzle end to re-tru the barrel. Repeat until you have minimal runout at the end of the barrel and 2 inches in. Some days you can dial a barrel in in 15 minutes - other days you can spend a couple of hours. Some days you just give up and go in the house and drink beer. The Mitutoyo tenth indicator is used to check and align chambers that are already cut. It goes right up into the chamber and will measure runout in the chamber as well as the barrel.

 

[Dabbler]

Here's my 2cents:

Only buy a test indicator new, from an authorized dealer. I love my Mitutoyo 513 series. I have it in half thou and tenths. best tool in my shop, and not too expensive. The other brands are fine also, but a tenths indicator is so precise, sensitive and prone to damage, I'd only buy new.

For threading a barrel for best results, you need to measure the size of the lands and make a brass plug to just fit. then indicate that to tenths and thread the barrel. We've done dozens for police tac teams in our area, and they moved to us because when they put moderators or flash suppressors on barrels with our threads, they can measure the difference in their accuracy. We were far more expensive that the other builders in our area.

Out of all the 'target' quality barrels we have threaded, as many as 50, only one OD was concentric to the bore within our measurement ability.

 

[Earl]

Here's my 2cents:

Only buy a test indicator new, from an authorized dealer. I love my Mitutoyo 513 series. I have it in half thou and tenths. best tool in my shop, and not too expensive. The other brands are fine also, but a tenths indicator is so precise, sensitive and prone to damage, I'd only buy new.

For threading a barrel for best results, you need to measure the size of the lands and make a brass plug to just fit. then indicate that to tenths and thread the barrel. We've done dozens for police tac teams in our area, and they moved to us because when they put moderators or flash suppressors on barrels with our threads, they can measure the difference in their accuracy. We were far more expensive that the other builders in our area.

Out of all the 'target' quality barrels we have threaded, as many as 50, only one OD was concentric to the bore within our measurement ability.

Here is an "indicated" barrel. No range rod, no brass plug - those are all "secondary" measurements. I prefer reading the barrel directly. You can see a slight bit of runout when the indicator is all the way in. I didn't video the muzzle end but it was running out over 40 thou when the first 2 inches of the chamber end was running true. Every barrel I have ever had in my lathe was "banana" shaped. It is almost impossible with the equipment being used by the barrel manufacturers to get one perfectly straight. The best one I ever has ran out about 3 thou at the muzzle end.

This is a Kreiger barrel. It took me about an hour to dial it in. Sometimes I get lucky and get it done in 20 minutes. Sometimes I can spend half a day.

 

[Ike Carlson]

The markings on the indicator are only there for reference. I indicate until the needle stops when it matters. A .001" needle that doesn't move is better than a .0001" needle that does. Lots of folks say you can only indicate down to the smallest mark on the dial, but that's bs. You can put smaller marks between the originals and have any resolution you want. Yeah, I know .0005" will sweep more than a .001", but it still moves and you can still get dead nuts with one. I used a .001" "last word" 2 days ago to indicate a pulley that needed to be reamed .001" and be dead nuts. It had to be bolted to my faceplate. I got it dead nuts and it was a success. The reason it had to be reamed was because the hole was tapered .0012" and the shaft would not go through. The wide side was .0002" over and the tight side was .001" under, so I only reamed the part that was under. The cut faded out all at once in a perfect ring, so I know it was dead nuts.

A barrel is ALWAYS indicated on the bore. As long as the indicator says "zero" by not moving, in 2 places at least 3 or 4 inches apart, it's good.
You can do great work with just a "wiggle stick" if you know how to use it right. Heck, I have cut really nice crowns on a WOOD lathe, because that's all I had available, and they were just as good as any other crown. The rifles shot 1/3 moa or better after the work. It's about understanding what you are using and knowing how to make it work.

Will a more accurately chambered rifle out-shoot one that is "off"? That depends mostly on the shooter. Most shooters can't do much better than about 1.5-2 moa, whether they admit it or not.

Edit: a .0001" indicator will move more than a .001", but that's not my point. You can only get so dead nuts, and there is a point where it doesn't matter any more.