Indicator/Grizzly Rod or Interapid Indicator to chamber barrel

Bran743

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Sep 6, 2011
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Oklahoma City
Hey folks. I'm gathering the equipment to start building my own rifles. I was about order some indicating rods, when I did some reading about using an Interapid indicator with an extension long enough to get up close to the throat area.

So my question is, what method(s) are you guys using to indicate your barrels when you are about to do a chamber?

-Brandon
 
Using the direct read is mandatory IMO at least double check another method. I use both the range rods and Grizzly just cause it's fast to rough in my bore and I don't have to watch the indicator bounce. I've tested several times and the range rods are repeatable to a .003, the Grizzly I can get to repeat in the tenths but it takes some practice but it's handy for deep chambers that the long reach indicator won't reach but I verify as much as I can with a dti.
 
Thanks for the feed back. If I under stand you right you are get the chamber in the ballpark with a rod (pick your flavor) then getting it to deadnuts 0 with a DTI?

How far into the chamber do you try an test at?

-Brandon
 
Using the direct read is mandatory IMO at least double check another method. I use both the range rods and Grizzly just cause it's fast to rough in my bore and I don't have to watch the indicator bounce. I've tested several times and the range rods are repeatable to a .003, the Grizzly I can get to repeat in the tenths but it takes some practice but it's handy for deep chambers that the long reach indicator won't reach but I verify as much as I can with a dti.
+1
 
Now if you have not bought the indicator yet, then please allow me to chime in.

I've been raving about the Interrapid indicator for twenty plus years. Just the best period, unless you get into the super high end Federal electronic indicator attachment for their electronic level ($5200.00 in 1980). Plus you have zero need for that kinda accuracy.

If you turn an indicator upside down after setting a zero point, you've lost everything. That's why you want the Interrapid or the Brown & Sharpe Best Test. They both have similar accuracy with no lag issues. 100% of the rest will. I'd almost swear the B&S is built by Interrapid and put in a different case. They have exactly the same feel (very important). Now I own a couple long wand Interrapids, and perhaps a half dozen of the standard wand Interrapids. I used mine daily, and they absolutely had to be right due to what I used them for. Honestly, I'm not a fan of the Interrapid .0001" indicators. They're just extremely touchy about movement. Harder to get them to settle down and stay that way. Most of the time I used the Interrapid .0005" indicators. But Oh you say I'm working down to two tenths!! Big deal, you need to learn to split the lines. The five tenths indicators is 100% easier to use. Remember that after you get down to five tenths or less, you start tracking movement of the needle. No movement of the needle will put you right where you wanta be.

I'm a machine builder, and trust me I thought nothing of splitting one tenth. No big deal once you get in the right frame of mind with the right equipment. Your lathe on a perfect day and with a perfect setup is probably going to be over .00075" error. Don't worry as they all are! I had a Monarch EE that I scraped and rebuilt everything on it. Added a 50 millionth set of scales, and set it on 12" of re-enforced concrete. It was as strait as any lathe I'd ever seen. Guess what? It was a three or four tenths machine at best. Nature of the beast. Just don't expect 50 millionth accuracy.
gary
 
My dial in process goes like this, load up the barrel center the outboard spider by eye, put the tailstock with a live center up to hold the barrel and I bring my 4 jaw up to holding the barrel.
I dial in the OD of the shank in just a couple passes then use a DeWalt cordless band saw and cut the shank to length, face it and chamfer the bore.
Range rod goes in and I dial in the bore, this takes a couple minutes with a quality barrel.
Depending on the chambering I'll go in with an indicator and dial in direct both the throat and the back of the chamber, if the throat is beyond the reach of my indicator I'll go in with the Grizzly rod and dial in with that and check the back of the chamber with the indicator. Run the lathe and let it warm up and do a little tune up then rally, I verify dial in before each op.
 
My dial in process goes like this, load up the barrel center the outboard spider by eye, put the tailstock with a live center up to hold the barrel and I bring my 4 jaw up to holding the barrel.
I dial in the OD of the shank in just a couple passes then use a DeWalt cordless band saw and cut the shank to length, face it and chamfer the bore.
Range rod goes in and I dial in the bore, this takes a couple minutes with a quality barrel.
Depending on the chambering I'll go in with an indicator and dial in direct both the throat and the back of the chamber, if the throat is beyond the reach of my indicator I'll go in with the Grizzly rod and dial in with that and check the back of the chamber with the indicator. Run the lathe and let it warm up and do a little tune up then rally, I verify dial in before each op.

This is exactly how I dial in my barrels as well. Has been working for me and this simple setup takes me less time to setup. The only difference in my setup is that I cut the barrel shank to length first with a slow cold cut chop saw first them I do everything the same.
 
I never take much from the ends, if I do, I use a parting tool.
This is exactly how I dial in my barrels as well. Has been working for me and this simple setup takes me less time to setup. The only difference in my setup is that I cut the barrel shank to length first with a slow cold cut chop saw first them I do everything the same.
 
I like to order my barrels an inch longer shank so I can cut all the lapping bell of both ends.

I don't know why you would cut much off the shank. You put a reamer down there and remove 2-4" of material any ways.

I could see only the potential on the muzzle end.
 
Ideally I like to dial on the same quality of bore through out the chamber, some barrels you'll see quite a lapping bell, same reasoning as knocking an inch of muzzle of, it's not a huge deal but if I'm ordering a barrel I like it that way.
 
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