45-70 throat reamer?

[Tatume]

Hello Folks,

Someone who has experience with the Manson throat reamer please tell me about it. I have never used any sort of chamber reamer. The gun is a current production Winchester High Wall. It has a SAAMI chamber, with essentially no throat at all. Thoughts appreciated. Thank you.

Take care, Tom

[montana_charlie]

Do you already have the reamer?
... or ...
Do you know how you want the new throat to be shaped?
CM

[Tatume]

Hi Charlie,

No, I don't have the reamer, nor have I decided upon a configuration. However, I wrote to Manson, and this is what they had to say:

"Thanks for your inquiry. As you described, the throat in your 45-70 can be extended with a separate Throating Reamer or you can simply convert the rifle to 45-90. A separate Throater is priced @ $40.00 (solid pilot) or $70.00 (removable pilot), plus shipping. These tools are normally driven with a 12” T-Handle--@ $16.00—which allows you to extend the throat without removing the barrel from the receiver. Depending on its profile, you may have to remove the buttstock in order to make complete turns with the Throater."

I don't know how this tool works. If it is piloted in the bore, and also in the body of the chamber, with a positive stop at the breech end when the correct depth of cut is achieved, then I should be okay. That is, as a neophyte, it would appear that I can't screw up. (I assume the operation should be generously bathed in cutting oil.)

On the other hand, if like so many other gunsmithing operations, some level of skill and "feel" is required, then I don't want to attempt it. I have only this one throat to cut, and I don't want it to be my own. :-)

Thanks, Tom

[montana_charlie]

Hi Charlie,

No, I don't have the reamer, nor have I decided upon a configuration. However, I wrote to Manson, and this is what they had to say:

"Thanks for your inquiry. As you described, the throat in your 45-70 can be extended with a separate Throating Reamer or you can simply convert the rifle to 45-90.
That seems like an odd pairing of options. You could almost think they see deepening the chamber as the same thing as creating a 'throat'.
Following that reasoning, you would then load long bullets in your 45/70 case, and the deeper chamber would accomodate them.

Maybe they are expert toolmakers ... and know nothing about shooting.


I don't know how this tool works. If it is piloted in the bore, and also in the body of the chamber, with a positive stop at the breech end when the correct depth of cut is achieved, then I should be okay. That is, as a neophyte, it would appear that I can't screw up. (I assume the operation should be generously bathed in cutting oil.)
I have never done the job, either. But, from the comments of others who have, there is some 'feel' and some handling practices which experience can only make better.
One thing is ... you turn the cutter backward as you (gently) insert it to make contact with the surface to be cut. As long as it turns backward, it can't 'dig in' to screw up those initial measurements required to establish the starting point.

As for how the rear of the cutter is held in alignment with the bore when using the T-handle, I would ask Manson that question ... if somebody here can't provide the answer.

CM

[Tatume]

Charlie,

The SAAMI chamber drawing for the 45-90 shows a nice, tapered throat. The drawing for the 45-70 shows an abrupt end of the chamber at the case mouth, with no throat at all. So, a correct 45-90 chamber would give a throat and the flexibility to load and shoot 45-70 as well as 45-90 ammunition. Accuracy would probably be best with the correct 45-90 cartridge.

My guess (and I intend to call Dave Manson and ask) is that the throating reamer puts approximately the same throat in the 45-70 chamber as the 45-90. It may be sort of like a 45-90 Kurtz, or a 45-90 chamber shortened by 0.3 inch.

Take care, Tom

[2Tite]

Tatume,
Yes, some "feel" is required as well as accurate measurement longitudinally into the chamber. If you've never done it, that T-handle can get you into trouble quickly. If you have no experience in this area.......go slowly and with patience. You can do it but it's not foolproof.

[montana_charlie]

Charlie,

The SAAMI chamber drawing for the 45-90 shows a nice, tapered throat.
I have the SAAMI index of Cartridge And Chamber Drawings, updated 10-17-2009.
It lists the 45/70. but none of the other .45 caliber cartridges based on the same head.
It is my understanding that they were deemed obsolete before the creation of the SAMMI organization, therefore there are no SAMMI specs for those cartridges ... among others.

However, I would like to see the 45/90 drawing you are referring to.
Unless I miss my guess, it's a Winchester spec'd chamber ... not SAMMI.

The drawing for the 45-70 shows an abrupt end of the chamber at the case mouth, with no throat at all. So, a correct 45-90 chamber would give a throat and the flexibility to load and shoot 45-70 as well as 45-90 ammunition.
I think it's unfortunate that some people believe that.

My guess (and I intend to call Dave Manson and ask) is that the throating reamer puts approximately the same throat in the chamber as the 45-90. It may be sort of like a 45-90 Kurtz, or a 45-90 chamber shortened by 0.3 inch.

Now, that is an idea I could go along with, but I think the Winchester 45/90 throat may be deeper than you may actually need.

My throat consists of a freebore (in front of the chamber cut) of .460" diameter, which is 0.10" long, and finishes with a leade of 1.5 degrees per side.

It is consistent with what some call a 'match chamber', and allows me to use most any bullet I choose. Manson could make a throating reamer of that shape, and it could be used for a chamber of any depth.

You now know everything that I do, so I'll leave it to you to finish your search for information.

CM

[Tatume]

Charlie,


However, I would like to see the 45/90 drawing you are referring to. Unless I miss my guess, it's a Winchester spec'd chamber ... not SAMMI.

Hmmm. I was certain I saw the drawing at the SAAMI web site, but it's not there. It turns out that the drawing I was thinking of was one sent to me by Dave Manson. Unfortunately, the file is in a format that I can neither save nor reproduce.

Anyway, you're right. It was not a SAAMI chamber drawing.

Take care, Tom

[XWrench3]

chambering is a very touchy thing. i had a professional gunsmith mess up a barrel. so basicly your taking the life of your rifle in your own hands.