lengthen throat on existing chamber?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by jlvandersnick, May 17, 2018.


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  1. jlvandersnick

    jlvandersnick Well-Known Member

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    I had a 28 nosler built and told the gunsmith I wanted the chamber throated for the 195 bergers. I got a sammi spec chamber (heavy sigh) and I'm having pressure issues.
    Can I lengthen the throat on the existing chamber or do I need to start from scratch? ? I see PTG has what they call neck and throat reamers.
    Thanks
    Jerry
     
  2. RockyMtnMT

    RockyMtnMT Official LRH Sponsor

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    Yes you can. Some smiths do not like to run a separate throat reamer. Make up a dummy round at the length that you would like. I am sure there are smiths here that would be happy to do the work for you.

    Steve
     
  3. shortgrass

    shortgrass Well-Known Member

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    Sure. But I avoid PT&G cutting tools completely. "Hobbyest tools", at best! It takes an experienced hand to set the throat where you want it using a throating reamer. I think doing the work on the lathe is better than trying to do it by hand. Those throating reamers are sharp, and you are not cutting much steel, so if you go "by feel" you can cut too far in a heart beat!
     
    Last edited: May 17, 2018
  4. odoylerules

    odoylerules Well-Known Member

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    I have a SAAMI 300 win mag chamber I’d love to lengthen the throat on. If you find a smith good enough to do this please pass it on.
     
  5. shortgrass

    shortgrass Well-Known Member

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    The "ideal" and fool proof way is to have the proper throat built into the finish chambering reamer. But lengthening an existing throat, with a throating reamer, is quit possible. But takes more care and time!
     
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  6. Edd

    Edd Well-Known Member

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    If you look at Greg Tannel's reamer list, it appears he cuts the chamber, the neck, and the throat with three individual reamers.

    I have also talked to JGS about reamers to lengthen the throat. They said some Gunsmiths have them grind a reamer that matches the chamber reamer that was used but they don't grind the edges to cut anywhere but the throat.

    That way you don't have to be concerned about going too deep but you are limited to that one cartridge and depth and the reamers are more expensive than a regular throating reamer.
     
    Last edited: May 17, 2018
  7. WeiserBucks

    WeiserBucks Well-Known Member

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    Am I missing something here ? Send it back to the gunsmith and have him do the work you requested and paid for .
     
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  8. Edd

    Edd Well-Known Member

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    I think you are missing something. Saying you want your chamber throated for 195 Bergers is pretty vague. The Gunsmith may think a SAAMI chamber is good for 195 Bergers.
     
  9. Smokepoles

    Smokepoles Well-Known Member LRH Team Member

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    It shouldn’t be a big deal, I’d send a dummy round and just have them punch it out. If your Smith can’t figure it out there’s plenty that will. Accurate ordnance has done it for me a few times.
     
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  10. elkaholic

    elkaholic Official LRH Sponsor

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    How far is the body of the bullet intruding into the case below the neck/shoulder junction? How much room do you have left in your magazine (if you aren't single loading)? IF the smith was clear on the request, and there was enough room, the bullet should have been seated near the neck shoulder junction when touching the lands. (Or up into the neck a bit)
     
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  11. BountyHunter

    BountyHunter Well-Known Member

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    This is perfect example of why you take the time to spec and buy your own reamer!!
     
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  12. shortgrass

    shortgrass Well-Known Member

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    Or, at minimum, supply your gunsmith with a dummy rounds, with the bullet seated where you want it. "Communicate",,, communicate effectively! Over the years I have seen why too many reamers/action/barrels/stocks ordered by the customer that weren't 'right', and then was expected to 'deal' with these 'not correct' components, without any added cost to the customer of course........... My time is as valuable to me as your time is to you!
     
  13. Canadian Bushman

    Canadian Bushman Well-Known Member

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    Dummy rounds are a safe bet on getting the chamber you want.

    I throat barrels out for people if requested, and over time i have found a process to allow me to control depth very accurately.

    I would advise anyone to throat the barrel when its being chambered. Its easier to get everything to run together.
     
  14. elkaholic

    elkaholic Official LRH Sponsor

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    That's the best way to be sure its concentric. Some guys that throat later have used a fire formed brass with the primer pocket drilled out for a snug fit on the throater shank that keeps things aligned really well! I think it might be a good idea to have a throater that's a couple tenths larger than the the finisher for for those jobs to make sure you don't have any steps.
     
    Last edited: May 20, 2018
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