Making a first generation forearm

Discussion in 'Browning Auto A-5' started by Biz, May 27, 2023.

  1. Biz

    Biz 20g

    Hello friends,

    I am restoring a pre first-war auto-5 were the stocks is gone. The buttstock is almost completed, just the checkering left to do. Now I have to do the forearm. I have tried to make one with a horizontal boring machine but there is too much play in the sliding parts of the machine and the spindle is not perfectly turning straight. I have decided to try with a metal lathe. Unfortunately, I am not a machinist and never use such a machine. I am seeking some advice. Here is what I did so far.

    First, not being certain that the center of my blank will be the same at the jaws then at 13 inches apart, I cut a thin piece of the blank (see the thin piece on the left) and center it into the four jaws chuck and then insert the blank into the jaws and checked it at 13 inches apart. It was still center.

    [​IMG]

    Secondly, I drill about 1/4 inches deep into the blank then, I installed the hole saw to create the lip that will fit into the receiver.

    [​IMG]

    [​IMG]

    Here is where I am not sure if I will succeed. I will have to use two half inches drill extensions to drill through the forearm and I wonder if they will flex and deviate off the center during the drilling operation. May be there is a better way?

    [​IMG]
  2. win7stw

    win7stw .30-06

    Looks like it’s coming along very well. There’s only one way to find out if that extension will deviate off center.
  3. win7stw

    win7stw .30-06

    The only other thing I can think of is to have a machinist build you a solid extension with a bigger OD than that little half inch extension. Once you have that made I would use a set of dial indicators to make sure that bit/extension are turning true
  4. Biz

    Biz 20g

    I was thinking indeed to have a 7/8" extension made of tempered steel with a tapered end to fit into the tail stock.
  5. win7stw

    win7stw .30-06

    Great minds think alike. I should have paid more attention. I missed the tailstock piece of info. I’d still make sure everything is true before burying the bit
  6. Auzzie

    Auzzie 20g

    Hi Biz,
    Have a look in your lathe accessories.bin You may have a fixed steady with all your back gears etc. it’s big cast 3 leg spider device that anchors underneath the ways. . Has 3 brass contacts that are adjustable for centre.
    1 First up still hold between centres while it’s still running true and machine a round section 40mm long roughed down in diameter to get rid of squares in your blank towards the tailstock end .
    2 Then set up your fixed steady around that new machined round section.
    3. adjust all the screw in points to contact surface gently.
    4. Run up with live centre still in as a check
    Nobody likes all the time and effort involved in setting this device up to do right and usually they are untouched in the accessories bin with screw cutting back gears 40 years later

    5. If all turning true you can take centre away and then use your tailstock with a jacobs chuck and your bit or preferred if you can borrow a tapered shank metal bit that’s close to diameter and use the Morse taper and sleeves in the tailstock.
    6. Safety and Caution always as wood grips wonderfully on metal tooling as does not clear as well ,especially in metal lathes with plenty of torque and horsepower and rip your blank clean out of chuck and into orbit.

    By way nice looking lathe you have there. Make sure you clean and love it as sawdust is its mortal enemy.
    win7stw likes this.
  7. Biz

    Biz 20g

    Well it works. I drilled the 1 5/16 and then the 1" holes and the bits didn’t deviate and the hole was centered. I wonder if the fact that the blank was turning and not the bits helped? However, I can clearly see the blank oscillating during the drilling process. The idea of using the fixed steady is a very good suggestion. It happens that I have that gizmo.
    Auzzie likes this.
  8. Auzzie

    Auzzie 20g

    Hi Biz
    Good to hear it all worked out for you and your alive to share the experience.
    Nothing worse than having a work piece come flying out the chuck unannounced at million miles per hour while your leaning over . Amazing how you can pull your head in quicker than a turtle when that happens.
  9. Auzzie

    Auzzie 20g

    Biz story time
    I did not know then but 40 years ago older guy used to bring me wood blanks to do exactly the job your doing as an apprentice in a metal lathe.

    He was master wood worker at a fancy fine furniture shop up town. When he died years later found out from the family he had a racket going where he would dock blanks from the firm's supplies and then at home nights manufacture heavy duty replacement forends for A5 and sell them at all the local gun clubs for drinking money.
    Rudolph31 likes this.
  10. daniel11994

    daniel11994 .22LR

    I've been thinking about how to make forends at home for a long time now. I'd concluded that the way you've done it is the only reasonable method but I'd been struggling with whether the drill extension would actually work. Happy to hear it went well and thanks for sharing your success with us all.

    This might be a way to source an elusive beavertail A5 forend. I've only ever seen one for sale on a gun in Germany.
  11. Fowlgunner

    Fowlgunner .22LR

    Here is how one of the big stock makers (Fajen, Wenig, etc) went about the A-5 style forarm.

    Will

    Attached Files:

    Rudolph31 likes this.
  12. Biz

    Biz 20g

    Here is example number 1 that I made from black walnut. I still have some final touches up to do. After having made the hole into the blank for the tubular magazine, I use a rotisserie style jig that allowed me to aligned perfectly the blank with the original forearm to be duplicated. Now I have to move to the next one that I will make from European walnut.


    [​IMG]


    [​IMG]


    [​IMG]


    [​IMG]
    Rudolph31 likes this.
  13. Ranger6

    Ranger6 Administrator Staff Member Administrator Global Moderator Forum Moderator

    Very nice. I am impressed with your skill and determination to make this happen.
  14. Rudolph31

    Rudolph31 .30-06

    Very nice, Biz. Happy Bastille Day.
  15. Biz

    Biz 20g

    Thank You Rudolph, but we celebrate more the St-Jean Batiste day. However, today is the 86th birthday of my mother and she is very proud to be born on July 14th.
    Rudolph31 likes this.
  16. Rudolph31

    Rudolph31 .30-06

    Happy Birthday to your mom!
  17. Auzzie

    Auzzie 20g

    Hi Biz
    Very impressive in thinking out the jig setup. Like how you centre drilled the threaded rod (Booker Rod in Aussie Trade Slang) and picking up on point of thumbscrews so you can take in and out repeatedly and be on axis.
    Actually thinking out and building jigs is way more involved and interesting than doing the actual job most times.
    Looks great result.
    Just got to convert you to seeing images of metal swarf instead of wood shavings on your lathe bed ways. That is one fine metal lathe you have tucked away in your workshop.
    Nice work.
  18. Biz

    Biz 20g

    Thank Auzzie, knowing that is coming from a long time family of machinists, that is a valued comment. I am glad you recognize the work involved into making a good jig, and you’re right it was almost if not more interesting making the jig than making the forearm.
    Making the buttstock will be more challenging. The reference for reproducing the buttstock is the hole or channel of the action spring tube. I think I will not run a threaded rod through the stock or should I?
  19. recoil

    recoil .410

    Very nice work I'm impressed. Steve!

Share This Page