Considering custom DIY bolt receiver

Discussion in 'DIY Projects' started by nulreference, Nov 11, 2013.

  1. nulreference

    nulreference New Member

    24
    0
    0
    ok im considering doing a custom bolt reciver and i cant find a real answer to a burning question i have.


    why are all the raceways on everything Squared off? (attaching picture)

    assuming everything else being equal as far as bearing surface area for the lugs
    would a rounded profile work? like i said attaching picture

    either i just found a much easier way to do the receiver (bolt will be a bit harder but meh) or im missing something and thats why im asking


    [​IMG]
     
  2. JayCody

    JayCody New Member

    315
    0
    0
    From what I understand the reason it is squared is so the bolt lugs lock into the chamber lugs securely. I may be wrong but almost all rifles are made squared. There must be a good reason.
     
    Last edited: Nov 11, 2013

  3. nulreference

    nulreference New Member

    24
    0
    0
    yes but is that reason something like.

    well its always been done that way so why change

    and for major gun manufactures this makes sense why rock the boat they can afford to do it the way its always been done.

    might have to make the rounded one and test to see of there are any issues
     
  4. clr8ter

    clr8ter New Member

    4,015
    0
    0
    OK, so I have to ask……why are we supposed to assume the rounded raceway has the same total area of the squared one? They don't.

    Given that the square one is the same size as the round one (ex. a .250" square, and a .250" diameter round), the square one has to have more surface area.
     
  5. hiwall

    hiwall Well-Known Member

    4,269
    22
    48
    The rounded ones are fine and have been used but locking faces of course have to have square profiles.
     
  6. nulreference

    nulreference New Member

    24
    0
    0
    by that i ment assume the rounded one is larger so the profile area is the same

    and locking faces being square im assuming you mean where the bolt lugs would engage the reciver lugs being flat faced front to rear and yes figured that would need to be or the bolt could blowback and jam itself in there
     
  7. SSGN_Doc

    SSGN_Doc Well-Known Member

    6,922
    42
    48
    If you were to do that and lose some bearing surface, why not make three lugs and space them out evenly around the bolt. You would also reduce bolt lift and thus speed bolt action while spreading the load agains the lugs more evenly around the bolt.
     
  8. hiwall

    hiwall Well-Known Member

    4,269
    22
    48
    Look at pictures of the Weatherby Mark V bolt.
     

    Attached Files:

  9. nulreference

    nulreference New Member

    24
    0
    0
    my goal is to reduce the need for complicated machining tasks.
    and a 3 lobed bolt would work as well

    I'd like a pattern anyone wit the mechanical aptitude to run a lathe and a mill/drill can make with a minimum of fus in a SHTF type of situation or just because they want to get into the making of prototypes
     
  10. clr8ter

    clr8ter New Member

    4,015
    0
    0
    OP, would you care to share what your end goals are? I'm confused. If SHTF, I'm pretty sure making firearms from scratch is going to be the least of your concerns, and a fair distance outside anyone's capabilities.
     
  11. nulreference

    nulreference New Member

    24
    0
    0
    the plan is to make a receiver blueprint that does not require expensive machinery
    something that in theory any machine shop could make.

    also i want to start weapon prototyping and i dont have a broach or EDM nor do i wish to invest in them if i dont need to

    call it an everyone gun and if you wait till SHTF then its probably a moot point anyways this would be a preparation step
     
  12. clr8ter

    clr8ter New Member

    4,015
    0
    0
    Hmmm, interesting. You have my attention. Questions: What about the barrel? Can't be made, you just going to pick one and order it? What about heat treating? Something tells me, (I don't know for sure) that certain gun parts (bolt & receiver come to mind) are heat treated. Also realistically can't be done by most people.
     
  13. nulreference

    nulreference New Member

    24
    0
    0
    idealy it will be using something like 4140 prehard or something else thats reasonably machinable at rc 34-40 and the goal was to use something like a savage barrel since they have "adjustable headspace" so to speak and require much less specialized equipment to install
     
  14. regload

    regload Member

    161
    1
    16
    Having been (among several other jobs) a machinist for more than 30 years, I fail to see what is easier to machine in that rounded profile you drew. For one thing, the mating parts, if square, are easier to make or otherwise obtain, for mating with the square profile. For another thing, a milling machine (vertical or horizontal), or a drill press, or an arbor press all will do broaching with the simple addition of an inexpensive broaching cutter. Perhaps enhancing one's machining ability and experience is the real ticket to success.
     
  15. nulreference

    nulreference New Member

    24
    0
    0
    i was of the impression i had to buy large keyway broaches and a broaching machine i was unaware a mill could do the job... time to research
     
  16. Axxe55

    Axxe55 The Apocalypse Is Coming.....

    7
    1
    0
    after reading through all of this. i have to think this is a solution looking for a problem that doesn't exist. bolt actions have been working fine for well over a hundred years, just like they are. and looking at your design, i just can't see it offering any advantages over what is already available.
     
  17. nulreference

    nulreference New Member

    24
    0
    0
    well until regload pointed out there are other ways to broach a raceway i was trying to do away with broaching or the EDM to open up to more people the ability to make a bolt action from scratch
     
  18. Axxe55

    Axxe55 The Apocalypse Is Coming.....

    7
    1
    0
    i still think it's a solution for a problem that doesn't exist. in your reference to a SHTF situation, what about a barrel? what about a bolt and a trigger?

    i seriosly doubt a person is going to be able to learn how to machine close tolerance gun parts overnight if SHTF.

    hopefully you do understand there is more to just throwing a peice of metal onto a lathe or a milling machine and making an action for rifle in short time.
     
  19. nulreference

    nulreference New Member

    24
    0
    0
    yes as i stated this is a prep build for SHTF or gun grab by the government

    "guns? what guns you have everything that is registered to me sir"

    as well as an expansion of my own know how and future prototyping
     
  20. Axxe55

    Axxe55 The Apocalypse Is Coming.....

    7
    1
    0
    umm...none of my firearms are registered and everyone of them was bought legally.

    i wonder how many FFL dealers there are in the United States? and with over 5 million gun owners, many with multiple guns, like myself, i wonder how long the search would take for them to determine how many guns i own?

    simply put, i have no intentions whatsoever of complying with a national gun registration.