• This Forum is for adults 18 years of age or over. By continuing to use this Forum you are confirming that you are 18 or older. No content shall be viewed by any person under 18 in California.

Chambering method advice needed for beginner

Hybrid284

Greetings

Beginner here and only chambered a few barrels.

I want to ask some advice from those that indicate your barrel at the muzzle and throat, plus a pre bore. Do you ever look an inch or so ahead of the throat out of curiosity?
I got surprised with one today that was more than 1 thou off of straight an inch ahead of the throat. So I did it Gordys way, but prefer the method above.

Should I not be tempted to indicate this area again? Is this excessive? Would you proceed anyway?

Thankyou. Regards Jake
 
That's a lot. Are you using a spider chuck on both the inboard and outboard ends and are you confident that the barrel was able to move freely while dialing in opposing ends to prevent bending?
 
X Count said:
That's a lot. Are you using a spider chuck on both the inboard and outboard ends and are you confident that the barrel was able to move freely while dialing in opposing ends to prevent bending?
Click to expand...
Yes outboard spider and ring on the 4 jaw. Barrel was moving freely, I tried multiple times, gently and just finger tight to make sure, going back and forward a few times. The same result each time
 
I use a long stylus interapid and indicate the future freebore area and as far as I can reach in front of it.

On the bigger magnums I’ll roughly indicate, then drill for clearance to get the interapid up into the barrel enough to reach desired areas.

I prebore with a very nice drill and then hit it with a carbide boring bar.

My setup is spiders front and rear.

I’m no pro or even a good machinist but that’s given me good results.94069EF7-E931-4414-BB24-FD836034883B.jpeg
 
SKWERLZ said:
I use a long stylus interapid and indicate the future freebore area and as far as I can reach in front of it.

On the bigger magnums I’ll roughly indicate, then drill for clearance to get the interapid up into the barrel enough to reach desired areas.

I prebore with a very nice drill and then hit it with a carbide boring bar.

My setup is spiders front and rear.

I’m no pro or even a good machinist but that’s given me good
Click to expand...
Im sure this setup also works, along with indicating both ends which makes more sense to me,except the one I ran into today. (It was a top barrel maker)
 
I use a long stem interapid to indicate throat and will check 1/4 to 1/2” either side and would like to see them run within 2 to 3 ten thousandths of each other.

Unless it is a bull barrel I find you can jack it around a bit in a pair of spiders and straighten it out just a touch. Also remember if you are measuring where you pressure points are you might be distorting the bore and causing the variation. A ten thousandth of an inch is a VERY small number. So small that I wager most of our measuring instruments are giving us feel good rather than actual values.
 
Hybrid284 said:
Im sure this setup also works, along with indicating both ends which makes more sense to me,except the one I ran into today. (It was a top barrel maker)
Click to expand...
Before I started doing my own I shot out a lot of Shilen prefits and I’m confident they were between centers, a few you could see irregularity cut lands where the reamer was obviously not concentric to the bore, they all still shot quite well to excellent.

Lots of way to do it.
A bit of curve in the bore comes in handy if you index it upward, free elevation.
 
DR_2297 said:
I use a long stem interapid to indicate throat and will check 1/4 to 1/2” either side and would like to see them run within 2 to 3 ten thousandths of each other.

Unless it is a bull barrel I find you can jack it around a bit in a pair of spiders and straighten it out just a touch. Also remember if you are measuring where you pressure points are you might be distorting the bore and causing the variation. A ten thousandth of an inch is a VERY small number. So small that I wager most of our measuring instruments are giving us feel good rather than actual values.
Click to expand...
My long stem interapid is .0005 increments.

 
Hybrid284 said:
Greetings Beginner here and only chambered a few barrels. I want to ask some advice from those that indicate your barrel at the muzzle and throat, plus a pre bore. Do you ever look an inch or so ahead of the throat out of curiosity? I got surprised with one today that was more than 1 thou off of straight an inch ahead of the throat. So I did it Gordys way, but prefer the method above. Should I not be tempted to indicate this area again? Is this excessive? Would you proceed anyway? Thankyou. Regards Jake
Click to expand...
Hybrid284 said:
Greetings Beginner here and only chambered a few barrels. I want to ask some advice from those that indicate your barrel at the muzzle and throat, plus a pre bore. Do you ever look an inch or so ahead of the throat out of curiosity? I got surprised with one today that was more than 1 thou off of straight an inch ahead of the throat. So I did it Gordys way, but prefer the method above. Should I not be tempted to indicate this area again? Is this excessive? Would you proceed anyway? Thankyou. Regards Jake
Click to expand...
It is aggravating when the ID decides to get squirrelly exactly where your throat is going be established. It’s like the initial gun drill decided to take a left or right turn.

This is the indicator I use. I pre drill, then reach up in there with one of these, indicate the lands where the throat will be, then single point bore to a predetermined size, then ream.

I always keep the ID of the muzzle running true.

As you probably know, if something is not straight, you decide what two points you are going to indicate and then machine the third point to match. I choose to indicate the ID of the muzzle, then the throat, then single point bore the chamber and ream. You then have three points dead true.

All the rest in between you don’t worry about.

selectumllc.com

Mitutoyo Series 513 513-504-10E – Shop Test Indicators Online | Selectum

Mitutoyo 513-504-10E Series 513 Dial Test Indicator, Pocket Type, 0.01", 0.0001" Graduation (Basic Set - 8 mm Stem, Stylus). Free shipping Mitutoyo authorized distributor
selectumllc.com selectumllc.com
 
Last edited:
SKWERLZ said:
Before I started doing my own I shot out a lot of Shilen prefits and I’m confident they were between centers, a few you could see irregularity cut lands where the reamer was obviously not concentric to the bore, they all still shot quite well to excellent.

Lots of way to do it.
A bit of curve in the bore comes in handy if you index it upward, free elevation.
Click to expand...
The chamber certainly looked good in the borescope. So lets see. Cheers.
 
Rich S said:
I have not experienced that. Just curious if you confirmed it was true runout or some imperfection in the barrel or set up issue. For true runout your high and low (should be 180 deg from each other) summed should equal the readings 90 deg to them summed.
Click to expand...
Hi Rich, im still learning but i dont think its setup, im fussy getting it right (and maybe have too many indicators). But the 1 thou was the high and low at 90 degree. So I assume true runout it's half that? Cheers
 
Hybrid284 said:
Sorry yes .001 on the needle. Would you still consider this ok?
Click to expand...
Where on the barrel did you initially indicate?
At the very ends?
If so you might want to think of the first inch of either end as scrap because of manufacturing and/or lapping process and indicate from 1” or so into the bore.
 
You must log in or register to reply here.

Similar threads

Looking for advice on this chamber
Replies
13
Views
730
X Count
Re barreling a Kimber 84 advice or tips?
Replies
3
Views
1,513
dakor
Welldone 7.5
Chambering 6.5 BRX
Replies
3
Views
257
msalm

Upgrades & Donations

This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.


Click Upgrade Membership Button ABOVE to get Gold or Silver Status.

You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.


To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.

Classified Ads

Forum statistics

Threads
169,043
Messages
2,269,479
Members
81,827
Latest member
KR55

Share This Page

Back
Top