Results 1 to 5 of 5

Thread: making a firing pin

  1. #1
    Gunco Regular amdhotprocessor's Avatar
    Join Date
    May 2007
    Posts
    429
    Feedback Score
    4 (100%)

    Default making a firing pin

    alright gyus,
    im starting the build on my new little scratch homebrew pistol. using a modified sten bolt.
    got my teacher let me use some tube.

    so hers my plan, in pretty much chronilogical order. and a few questions at the end i need some read good advice on

    1 in a few days, anneal my bolt and carburize it in the furnace in the shop.

    2 once annealed, cut a flat out to clear and old rommy ak hammer,

    3 fabricate a firing pin to the specs i need, (to be determined) and drill a hole for it, in the
    lathe of course.

    4 once i make my pin, and mod the bolt, re heat treat and temper as needed.

    5 once i am all taken care of on the bolt im gonna get that pipe, and immidiatly install a rail of key stock or tool steel rod, and weld in the top of the tube,

    6 i need to then design a rear plug for the tube and a recoil system, i will use 2 steel rods to utilize springs( i make my own springs ) and make a stopper/buffer to put in place.

    7 i will lathe me out a cocking handle and position it on the left of the gun. the mag well on bottom front and eject straight up

    8 I could buy a mag well,,,,, lol , I think ill make my own thankyou, would you like some tea. Im working on tht right now in bed.

    9 Ill be using sten mags(cuz that what i got) so im sure my famous feed ramp will be in order.

    10 I guess from here, ill go ahead and mount the fcg. ill make the cuts and mesurements nessesary and im going to cut the center section of a defunct ak build reciver and weld to the bottom of the tube, or i will fab a body from 1/8 plate and a grip stick in which i may fab my own ironwood grips with a hand rub oil finish.

    11 once i have this figured, ill mount the barrel supported in a single yet long trunnion from the lathe

    12 now i like the mp40 sight so.... ill make my own! hehehehe hahahhah muahahaha

    13 to top it off i think i will make a thread on shrowd so i can swithch between the mp40/m3 grease gun look to th tac 9 look with allthe ventalation holes. the metal will probably be flat black..

    THIS IS GONNA KICK ASS!

    now i have a few question,
    1 What kind of material do i want to make my firing pin from? tools steel? heate treated high carbon?

    2 how would one figure how much spring you need to cycle right or at least close? i thought mabey one longer and lighter then a real heavy one at the 1/2 way point.

    3 idea on how to close up the rear and not be permanant so the gun can be dissasymbled.
    i thought a nice round ended plug with a large pin and a reienforcment block on the out side. but needs to be strong unless i can stop the bolt from inpacting anything hard. like using a secone heavy spring

    any ideas yall have please feel free, id love to incorperated someones ideas to better the design, budget/ability willing.
    i need quick help on the pin thought, i have a narrow window for time to use the heat treater because the teacher only uses it 2 a semester, and tha s it

    thanks all MIKE
    Cheap bastard plus ghetto tools=quality AK build

    PLEASE VOTE IN '08 FOR YOUR CONSTITUTIONAL RIGHTS!!!!!!

    RON PAUL '08

  2. #2
    Gunco Good ole boy kernelkrink's Avatar
    Join Date
    Jun 2004
    Posts
    5,026
    Feedback Score
    2 (100%)

    Default

    1: I would use a high carbon steel, the tool steel might be a bit brittle. Brownells sells some stock for making firing pins from scratch, "La salle fatigue proof steel"

    http://www.brownells.com/aspx/ns/sto...ail.aspx?p=565


    2: Measure the force of the original STEN spring (compress it on a scale) and start there. Since you are taking weight from the bolt I would start out a bit stronger. A rubber buffer might be in order as well, most of the modern blowbacks use them.

    3: Threaded end cap? Lots of subguns use that type, many with interrupted "cannon breech" threads so a partial turn releases it. Or just use the original STEN parts. Cut the washer shaped section off the stock and use it as a retainer plate inside the original rear housing.

  3. #3
    Gunco Regular amdhotprocessor's Avatar
    Join Date
    May 2007
    Posts
    429
    Feedback Score
    4 (100%)

    Default

    problem...... there are no other sten parts/// just barrel and bolt/
    ibuilt the parts kit of the sten into a semi mk3

    and great idea on the spring
    Cheap bastard plus ghetto tools=quality AK build

    PLEASE VOTE IN '08 FOR YOUR CONSTITUTIONAL RIGHTS!!!!!!

    RON PAUL '08

  4. #4
    aka: SDK1968 dutigaf's Avatar
    Join Date
    May 2006
    Posts
    4,029
    Feedback Score
    14 (100%)

    Default

    sounds like you've got most of it covered.. although length of your FP is gonna depend on your hammer position. unless you can just move the hammer pivot to wherever you want?

    lets see lots of pictures as you go..
    say what you mean & mean what you say


  5. #5
    Gunco Regular amdhotprocessor's Avatar
    Join Date
    May 2007
    Posts
    429
    Feedback Score
    4 (100%)

    Default

    i been thinkin that the ak reciver section im using to house the fcg will be on a dtatchable rail hat will allow acces to the fcg for service and allow front to back motion to cover any hammer swing geometry issues.

    i guess i can use mild steel for the pin and carburize it and heat treat, and make several of em so if they are prone to breaking. i have more. im gonna make em simple tho, just 1 step.

    im actually getting close to being able to assymble. as soon as i get my fp hole done and a fp made

    i may make one from stainless to see if that is better.
    Cheap bastard plus ghetto tools=quality AK build

    PLEASE VOTE IN '08 FOR YOUR CONSTITUTIONAL RIGHTS!!!!!!

    RON PAUL '08

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
  •