Results 1 to 5 of 5

Thread: Chamber Reaming

  1. #1
    Happy Camper hcpookie's Avatar
    Join Date
    Feb 2004
    Location
    Colorado Springs
    Posts
    7,691
    Feedback Score
    3 (100%)

    Default Chamber Reaming

    I wanted to start a new thread on this, since there is so much good information that this subject requires. Let's collect as much info and tips as we can!


    I'm starting with a general overview of the chamber reaming process that I have read. I know from my limited experience that the condition of the lathe is important. If you can't true up the lathe, then you don't need to be reaming a barrel on it!

    The lathe requires a steady-rest to be used to support the barrel. That gives you two support points - both the head and the steady rest. You must true up the barrel so there is little, if any, runout. This is the most time-consuming part of the process. PREPARATION IS KEY! Only if the barrel is properly prepared can the reamer do its work.

    Use plenty of cutting oil, and be sure to clear chips as often as possible. Low RPMs are important so the reamer doesn't dull or seize. Recommendations I've read are "up to " 200 RPM for the reamer.

    If you are not sure that the outer diameter of the barrl is true, then use the dial indicator to measure against a tight-fitting plug in the bore. That will ensure the chamber is calibrated to the bore and not the outside barrel diameter. This may not be a necessary step.

    With the barrel true, use a starter bit to cut a shallow recess in the barrel. This will help keep the cutter aligned when it starts to bite. Use either a roughing reamer or an under-sized drill bit to start the cut. Cut to a point before the chamber shoulder should begin. Then remove the rougher and use a finishing reamer for the final part of the cut.

    Use either a headspace gauge or some other measuring device to measure the depth of the cut. Too deep and you'll have to remove metal from the breech to get it right. Too shallow, keep on cutting.

    A new tool I've discovered (thank Bradrock!) is a "floating reamer holder" that lets a slightly out-of-spec tailstock do the work. It lets the reamer "float" by using either a spinning collar or a ball bearing for the axial thrust. The reamer is held in place by either a box wrench or a tap wrench.

    Finally, you can polish the chamber with sand paper or a dremel polishing wheel, then with a metal polish like Flitz.




    You guys out there with more experience and knowledge on this topic, please post more info, or corrections to my short explanation!
    Gunco Member #10

    http://pookieweb.net


    The "original" Boltcutter Rivet Squeezers:
    http://pookieweb.net/AK/rivet/boltcutters/boltcutter.htm


    Project Pink - the Pink and Blue AK-74:
    http://pookieweb.net/pink/pink.htm

  2. #2
    Happy Camper hcpookie's Avatar
    Join Date
    Feb 2004
    Location
    Colorado Springs
    Posts
    7,691
    Feedback Score
    3 (100%)

    Default

    A few links:

    Chambering .50 cal rifles - chambering overview:

    http://www.riflebarrels.com/articles...le_barrels.htm

    Brownell's listing for floating chamber reamer:

    http://www.brownells.com/aspx/ns/sto...+REAMER+HOLDER

    Another floating reamer, appears to be tailored to shotguns:

    http://www.colonialarms.com/catalogpdf.html

    The Clymer catalog lists reamers and floating reamer holders, among other cutting tools

    http://www.clymertool.com/catalogue/index.html
    Gunco Member #10

    http://pookieweb.net


    The "original" Boltcutter Rivet Squeezers:
    http://pookieweb.net/AK/rivet/boltcutters/boltcutter.htm


    Project Pink - the Pink and Blue AK-74:
    http://pookieweb.net/pink/pink.htm

  3. #3
    Gunco Regular Gunter's Avatar
    Join Date
    Sep 2005
    Posts
    456
    Feedback Score
    1 (100%)

    Default

    Like HC said index off the bore not the outside. Most bores are off just a hair.

    I would be careful using a standard drill bit to rough the chamber. They can wonder off center. A piloted drill bit will stay with the bore (learned that the hard way installing some liners).

    The way that I was shown was to set up the barrel like HC said. Then he placed a faced square stock piece in the tool post. The end of the reamer has an indent and he took a ball bearing with a little grease and stuck it to the reamer. Oiled everything up, started the lathe, held the reamer with a wrench, and let the reamer/ball bearing ride against the square stock. Sort of a poor man's floating holder. Cut very little and remove to clean the chips. When you get down to the last few thousands, you can lock the slide down and use the compound crank to know how much you are removing.

    If you get any chatter while cutting....start over. Chatter will leave a fluted chamber.

  4. #4
    No Hope For Me 1biggun's Avatar
    Join Date
    Oct 2005
    Posts
    13,589
    Feedback Score
    14 (100%)

    Default

    I would be careful using a standard drill bit to rough the chamber. They can wonder off center
    That was one of the things I forgot to mention. my gunsmith buddy warned me last nightnot to use a standard drill. he said if it gets a little off center that you will likely break the reamer as it has a pilot and will bind and break as the piolet tries to go in the true bore.

  5. #5
    No Hope For Me 1biggun's Avatar
    Join Date
    Oct 2005
    Posts
    13,589
    Feedback Score
    14 (100%)

    Default

    MY gunsmith also mentioned many years ago he new of guys that cut straight wall and taperd/non necked chambers with a boring bar with acceptiable results. this is some thing I was proposing recently. (sorry for going slightly off topic) A 50. beowulf is a non necked case and may possably be done this way. A old barrel would make for god practice.

Search tags for this page

There are currently no search engine referrals.
Click on a term to search our site for related topics.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •