Cutting mrod barrel breech seal groove



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Offline lennyk

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Cutting mrod barrel breech seal groove
« on: December 27, 2018, 05:11:58 AM »
Looking to try a new barrel for my marauder next year,
Can anybody point me to the correct bit to use for cutting the internal groove for the breech seal on .177?
Thanks,
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Offline Bob Pratl

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Re: Cutting mrod barrel breech seal groove
« Reply #1 on: December 27, 2018, 06:43:36 AM »
You will have to use a short 1/4" boring bar and grind the insert/bit to the proper groove dimensions.
You may have to fabricate your own boring bar to use 1/8" round HSS inserts.
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Offline nervoustrigger

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Re: Cutting mrod barrel breech seal groove
« Reply #2 on: December 27, 2018, 11:50:42 AM »
Another option you may want to consider is counterboring for the O-ring and adding a cap over the end to capture it.  Hatsan does their PCP barrels this way.  An added benefit is itís easier to replace the O-ring when the time comes. 

Offline rsterne

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Re: Cutting mrod barrel breech seal groove
« Reply #3 on: December 27, 2018, 04:31:01 PM »
Or you can just grind up a custom tool bit from a 3/16" or 1/4" square bar of HSS tooling....



I used a Dremel cut-off wheel to do the final shaping and sharpening.... works great....  8)

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Re: Cutting mrod barrel breech seal groove
« Reply #4 on: December 27, 2018, 06:30:27 PM »
Guys
Please forgive me, I have never held or seen an M Rod, Sorry,

Just where is this "O" ring seal at, on the breech face or bbl face, and why is it there,
it's main purpose is to seal what etc.

Just slightly confused.........normal for me.
I'll go stand in the corner, again........ :-[

Tia,
Don
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Offline YEMX

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Re: Cutting mrod barrel breech seal groove
« Reply #5 on: December 27, 2018, 06:43:23 PM »
Guys
Please forgive me, I have never held or seen an M Rod, Sorry,

Just where is this "O" ring seal at, on the breech face or bbl face, and why is it there,
it's main purpose is to seal what etc.

Just slightly confused.........normal for me.
I'll go stand in the corner, again........ :-[

Tia,
Don

the seal is inside the barrel, and seals against the bolt probe...

bad pic from the web:
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Online Nvreloader

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Re: Cutting mrod barrel breech seal groove
« Reply #6 on: December 28, 2018, 12:31:33 PM »
Tom

Thanks for the photo, now I see...........

Tia,
Don
  • Western  NV
Hammerli 850 Air Mag -17 cal x 2, 22 cal
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It is time to restore the American precept, that each individual is accountable for their actions."
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Offline KnifeMaker

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Re: Cutting mrod barrel breech seal groove
« Reply #7 on: January 01, 2019, 09:07:30 AM »
Wish I had the room for  a small lathe inthe shop. Would make life much easier!
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Offline PakProtector

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Re: Cutting mrod barrel breech seal groove
« Reply #8 on: January 03, 2019, 08:33:18 PM »
For you, only the best, a Monarch 10EE. It is small, at 10x20...and 3600 pounds.
https://i.ebayimg.com/images/g/IpUAAOSw~gRVv4uI/s-l1600.jpg
cheers,
Douglas
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Offline Hobbyman2007

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Re: Cutting mrod barrel breech seal groove
« Reply #9 on: January 03, 2019, 11:28:59 PM »
Iím using a cheap 9x20 Barbour freight and have it sitting on a reused kitchen table . It really doesnít take that much room . It has its limitations but none are exceeding my limits . Iím learning every time I turn it on . Almost as much fun as shooting .
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Offline KnifeMaker

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Re: Cutting mrod barrel breech seal groove
« Reply #10 on: January 05, 2019, 02:52:49 AM »
That's pretty sweet Douglas! It would push me right out of my small shop though. lol


Denis, I don't even have room for that!


Mike
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Offline PakProtector

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Re: Cutting mrod barrel breech seal groove
« Reply #11 on: January 20, 2019, 07:56:51 AM »
That's pretty sweet Douglas! It would push me right out of my small shop though. lol


Denis, I don't even have room for that!


Mike

The 10EE is a particular sweetie. For being only 10" swing and 20" between centers it weighs nearly 2 tons. AC motor turns a DC generator and the spindle is run on that DC...

From the web: Medium-power thyratrons found applications in machine tool motor controllers, where thyratrons, operating as phase-controlled rectifiers, are utilized in the tool's armature regulator (zero to "base speed", "constant torque" mode) and in the tool's field regulator ("base speed" to about twice "base speed", "constant horsepower" mode). Examples include Monarch Machine Tool 10EE lathe, which used thyratrons from 1949 until solid-state devices replaced them in 1984

So picture yourself in 1983, buying a $120,000 tool room lathe and discover it still has tubes in it...LOL
cheers,
Douglas
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Offline lennyk

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Re: Cutting mrod barrel breech seal groove
« Reply #12 on: February 14, 2019, 10:42:47 PM »
Hey Bob,

Do you normally use a little positive rake on this tool even as it is not a point cut?

Or you can just grind up a custom tool bit from a 3/16" or 1/4" square bar of HSS tooling....



I used a Dremel cut-off wheel to do the final shaping and sharpening.... works great....  8)

Bob
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