A moron and his uni-throater...

[Coyote Shadow Tracker]

What was the reason why you wanted to use the Uni-Throater in the first place? Evidently for a longer bullet. What bullets were you using and what bullets do you want to use? What is the desired difference for the original chambering? (how much do you want to remove)
I have used Uni-Throaters and it is fairly easy to remove metal with them lengthen the throat.
If you are using a Hornady OAL Guage, CASE and Comparator you should be able to get the exact measurement (before & after)

 

[StumpyJohnson]

I'll try this.

(edit) My suspicion it that I'll see marking in the ink, but it will be from a diameter somewhere between the bore diameter and the groove diameter. My suspicion is that the lead angle of the reamer is so slight and the original freebore/point of tangency so deep relative to other cartridges that the standard 6.5 uni-throater cannot reach deep enough to affect change. Does that make sense?

I took a bullet with a known CBTO measurement, seated it with .002 of neck tension at .005 of jamb (CBTO was 2.885 I seated bullet @ 2.890). then painted it with prussian blue. Stuffed it in till the case shoulder bottomed out, the round stuck in the chamber upon extraction of the case and showed markings. Then reality folded in upon itself and a black hole formed. *** is going on? I'll be placing a call to the peeps at PTG. Not because I think their product is faulty but because I want someone to confirm I haven't been licking poisonous frogs.

 

[StumpyJohnson]

looked up the 26 Nosler it has a 3 degree angle and my uni throaters have 1.5 degree. maybe you are just changing the angle and haven't got to cutting the freebore yet, cutting .120 is barely enough to change the angle and won't be even adding length yet. really need borescope dont screw up your barrel

This is along the lines of my thinking. But I'll run out of thread on the uni-throater depth adjustment soon. I think 26 nosler is a bastard of a round that no one should bother with.

 

[StumpyJohnson]

What was the reason why you wanted to use the Uni-Throater in the first place? Evidently for a longer bullet. What bullets were you using and what bullets do you want to use? What is the desired difference for the original chambering? (how much do you want to remove)
I have used Uni-Throaters and it is fairly easy to remove metal with them lengthen the throat.
If you are using a Hornady OAL Guage, CASE and Comparator you should be able to get the exact measurement (before & after)

I want to seat copper bullets passed the donut. I'd like to be able to seat Cutting Edge lasers or hornady eld-x's such that the boat tail is not stuffed passed the neck shoulder junction. .120 was an average that accomodated a few of the bullets I'm playing with, to be honest to shoot the bullet I want my calculations put me at .215 depth of cut. But baby steps I figured.

 

[Bob Wright]

looked up the 26 Nosler it has a 3 degree angle and my uni throaters have 1.5 degree. maybe you are just changing the angle and haven't got to cutting the freebore yet, cutting .120 is barely enough to change the angle and won't be even adding length yet. really need borescope dont screw up your barrel

Agree, the metal removal is coming from the end of the leade, as opposed to the start of the lead. 2° difference is causing the measurement to bullet ogive to not move.
Don't do any more until you can verify where the material removal can be seen. Applying some machinist bluing onto the leade can help see the reamer cleanup with the aid of a borescope.

 

[can1010]

Agree, the metal removal is coming from the end of the leade, as opposed to the start of the lead. 2° difference is causing the measurement to bullet ogive to not move.
Don't do any more until you can verify where the material removal can be seen. Applying some machinist bluing onto the leade can help see the reamer cleanup with the aid of a borescope.

i just played in my quickdesign with changing angle and it will take .113 give or take just to change the angle before lengthening the freebore

 

[StumpyJohnson]

i just played in my quickdesign with changing angle and it will take .113 give or take just to change the angle before lengthening the freebore

This is what I needed. I think before I get to noticeable change I'll hit the shoulder of the throater and screw up the neck of my chamber.

 

[can1010]

do you have a uni throater or a neck/throat reamer? the uni throater never touches any part of the chamber with the cutting surface. it only cuts throat and leade angle.

 

[StumpyJohnson]

do you have a uni throater or a neck/throat reamer? the uni throater never touches any part of the chamber with the cutting surface. it only cuts throat and leade angle.

Unless you adjust the stop collars all the way up, then you get about . 300 of shoulder into the neck that's about . 310 in my case. Its stamped uni-throater 6.5.

 

[StumpyJohnson]

I'm gonna get into a bottle of rye, I'll update this thread after my convo with PTG.

 

[Coyote Shadow Tracker]

Stumpy wish you best of luck. It is frustrating when trying to make an improvement in shooting especially when working on an expensive barrel, trying to make the fix yourself. Always makes you feel better when you do your own work. Also you can then only blame yourself.
Contact PTG and they can help you out. Probably many UTubes on the web to help out.
Over 50 years learning most things on my own by trial & error and some really good reloaders/gunsmiths to help out along the way. It's been a hard road and wish that I had asked more from other people. Could have done some projects 5-10xs faster and better. I never turn down an idea-may not use it for one application but would for others.
If there is anything we can do to help you out with anything please contact us. Wish people were there to offer certified help as we went along. Sometimes in Business people don't share as they should.
I am confident that everything will work out well with your rifle chamber throat and it will shoot Copper GREAT. You will be happy!
You are definitely learning
Thanks
Len & Jill

 

[StumpyJohnson]

Stumpy wish you best of luck. It is frustrating when trying to make an improvement in shooting especially when working on an expensive barrel, trying to make the fix yourself. Always makes you feel better when you do your own work. Also you can then only blame yourself.
Contact PTG and they can help you out. Probably many UTubes on the web to help out.
Over 50 years learning most things on my own by trial & error and some really good reloaders/gunsmiths to help out along the way. It's been a hard road and wish that I had asked more from other people. Could have done some projects 5-10xs faster and better. I never turn down an idea-may not use it for one application but would for others.
If there is anything we can do to help you out with anything please contact us. Wish people were there to offer certified help as we went along. Sometimes in Business people don't share as they should.
I am confident that everything will work out well with your rifle chamber throat and it will shoot Copper GRAST. You will be happy!
You are definitely learning
Thanks
Len & Jill

Cheers to you my friend! Thanks for the positive words!

 

[Coyote Shadow Tracker]

I'm gonna get into a bottle of rye, I'll update this thread after my convo with PTG.

Wish I could join you for a glass!!!
Sure could use one myself.

 

[ARlife4me]

The barrel is out of the action and in a vise. You cannot use the comparator and close the bolt.

(edit): The shoulder of the modified case meets the shoulder of the chamber and the relative measurement is taken from there. The dummy case I made has a score mark that indicates .100 from desired depth of cut to serve as a benchmark.

I realize that you can't use the comparinator when bolt is closed. I didn't know if you were checking measurements without the action installed. The dummy round inserted and bolt does close or not?