Drilling barrel pin
Page 1 of 2 1 2 LastLast
Results 1 to 15 of 26
Like Tree11Likes

Thread: Drilling barrel pin

  1. #1
    Senior Member

    Member #
    17467
    Join Date
    Feb 2010
    Location
    Trigonia, Tn.
    Posts
    404
    Liked
    53 times

    Drilling barrel pin

    Got one of AK Builders barrel pin press plates last week. Was installing a virgin barrel in a trunnion today, head spacing and drilling for barrel pin. The plate makes a great fixture to use on the mill. Hungarian trunnion. Measured the difference in height of the top groove where the receiver slides in and the main body with dial calipers. Ran the leveling screws in plate out to same height so BAM!!!, trunnion was level and supported. I had bought some 6.5mm drill bits off flee bay so I cut the shank off one and chucked it up in the mill. Clamped barreled trunnion in plate, ran the 6.5mm drill stub down and x-runny, y-runnied it until the stub slipped into the trunnion barrel pin hole. I was so proud of myself!!!! Old news to some but thought I would share.
    Last edited by Longshot1; 04-03-2017 at 08:05 PM.
    AK shooter and PumpStation666 like this.

  2. #2
    Senior Member

    Member #
    17467
    Join Date
    Feb 2010
    Location
    Trigonia, Tn.
    Posts
    404
    Liked
    53 times
    Man this plate is the shiz-nit!! I had messed up one barrel drilling barrel pin on a fixture I made. New plate is easy to clamp on the mill and easy to flip and drill from both sides. Finished third trunnion/barrel assembly on it today. Waiting to get my sandblast cabinet before finishing builds. Three waiting for riveting. Trying to get my son involved as he recovers from brain injury. He likes to watch for a while but then gets frustrated that he can't do the work too. At that point we ride the 4 wheeler down in the pasture and just talk.

  3. #3
    Super Moderator
    Supporting Member

    Member #
    21201
    Join Date
    Feb 2012
    Location
    PNW
    Posts
    11,337
    Liked
    6440 times
    I haven't checked out Curtis's site lately for tools. I was just on Rforbus site last night and he's got some new tools out. Nice to see there are options these days.

  4. Remove Advertisements
    TheAKForum.net
    Advertisements
     

  5. #4
    Senior Member

    Member #
    23017
    Join Date
    Sep 2013
    Location
    Arizona
    Posts
    628
    Liked
    137 times
    Robert Forbus makes the best tools for building AK's. AKB's tools I have to modify them or improvise with them to get them to work right for me.

    As far as drilling barrel pin holes I use a 7mm gauge pin to center the barrel pin hole I use a V-block to grip the barrel put a jack screw underneath the trunnion or receiver to support it from underneath. I'll use either 1/4", 6.5mm, 17/64" end mills plunge all the way through on both sides, and then I'll use a 7mm reamer plunging only through one side all while using plenty of cutting oil. That's just my method of doing that particular task.
    At the factories were they manufactured AK's they usually don't make sure they're set up is leveled, ridged, or square so the original hole can be difficult to machine it the exact same way. I found that leveling the trunnion and receiver isn't a reliable way to drill barrel pin hole. It's best to align the spindle with the hole of the breach block a lot of builders complain about drilling into virgin trunnions and barrel components. I'd prefer to use virgin AK parts cause you can make sure that you're drilling the holes correctly and not have to worry about egging the damned holes.
    BR7.62 likes this.

  6. #5
    Member

    Member #
    34697
    Join Date
    Jul 2016
    Location
    PA
    Posts
    31
    Liked
    10 times
    I gave up drilling my barrel pin holes, my gunsmith does it for $35. I have tried to do it myself but, my drill press and my luck just doesn't cut it.

  7. #6
    Senior Member

    Member #
    23017
    Join Date
    Sep 2013
    Location
    Arizona
    Posts
    628
    Liked
    137 times
    You need to use a mill to drill barrel pin hole unless it's a virgin breach block than you can use a drill press. When ever I've drilled barrel pin holes with a drill press I always have to ream for an oversized barrel pin.
    PumpStation666 likes this.

  8. #7
    Super Moderator
    Supporting Member

    Member #
    21201
    Join Date
    Feb 2012
    Location
    PNW
    Posts
    11,337
    Liked
    6440 times
    The barrel pin hole I use a drill press and a 7mm bit. Never had any issues.

    For the smaller 3 and 4mm holes I use a hand drill drilling from both sides.

  9. #8
    Technical Advisor

    Member #
    2371
    Join Date
    Aug 2006
    Location
    Columbus, Ohio
    Posts
    13,083
    Liked
    2136 times
    For virgin or pre-drilled trunnion barrel pins I use a 17/64 drill bit and then ream with a 7mm. I use a 1950's USA made drillpress .
    Up until the last two years I had machine shop access to a vertical mill etc. The drill press works fine though.


    T_AZ-AK_boy likes this.

  10. #9
    Senior Member

    Member #
    45065
    Join Date
    Apr 2017
    Posts
    204
    Liked
    52 times
    Quote Originally Posted by 22many View Post
    The barrel pin hole I use a drill press and a 7mm bit. Never had any issues.

    For the smaller 3 and 4mm holes I use a hand drill drilling from both sides.
    This all day

  11. #10
    Senior Member

    Member #
    23017
    Join Date
    Sep 2013
    Location
    Arizona
    Posts
    628
    Liked
    137 times
    Quote Originally Posted by AKBLUE View Post
    For virgin or pre-drilled trunnion barrel pins I use a 17/64 drill bit and then ream with a 7mm. I use a 1950's USA made drillpress .
    Up until the last two years I had machine shop access to a vertical mill etc. The drill press works fine though.


    Now that's a nice drill press. After being introduced to a Bridgeport mill it's not the same as using a drill press. I do work at a machine shop that has a couple manual Bridgeport mills, but I don't like asking to use company equipment for personal use even if I'm off the time clock. I have an older friend who's a cool guy and a machinist for a railroad company. At his home he has a barn in his backyard with a few machine tools a Kent manual mill and Leblond manual lathe. When his machine tools aren't set up for a particular project he's working on we'll make tools for building AK's and do any machining work that needs to be done such as drill for barrel pin holes. He doesn't build AK's, but he does like to help me work on them look at all the parts and say that the alleged factory machinists who make these AK parts suck at their job LOL.

  12. #11
    Technical Advisor

    Member #
    2371
    Join Date
    Aug 2006
    Location
    Columbus, Ohio
    Posts
    13,083
    Liked
    2136 times
    That drill press came from the personal machine shop I used to have access to. A Bridgeort vertical mill as well. But it weighted 1500 pounds and no room at my place for it. So it goes.

    I did get a Logan lathe from the shop. It was the smallest of the three there. I need tomake room to set it up.




  13. #12
    Senior Member

    Member #
    23017
    Join Date
    Sep 2013
    Location
    Arizona
    Posts
    628
    Liked
    137 times
    That lathe is historic perhaps more than a Hardinge Chucker. Looks like you'll only be able to make small parts machine tool though. You need to get that bad boy set up and start making chips. Does that machine require 3 phase power to run it?

  14. #13
    Technical Advisor

    Member #
    2371
    Join Date
    Aug 2006
    Location
    Columbus, Ohio
    Posts
    13,083
    Liked
    2136 times
    It is 110 AC power. Has screw feed drive and I have the steady rest. Just need a live center for the tail stock.

  15. #14
    Senior Member

    Member #
    17467
    Join Date
    Feb 2010
    Location
    Trigonia, Tn.
    Posts
    404
    Liked
    53 times
    Quote Originally Posted by T_AZ-AK_boy View Post
    Robert Forbus makes the best tools for building AK's. AKB's tools I have to modify them or improvise with them to get them to work right for me.

    As far as drilling barrel pin holes I use a 7mm gauge pin to center the barrel pin hole I use a V-block to grip the barrel put a jack screw underneath the trunnion or receiver to support it from underneath. I'll use either 1/4", 6.5mm, 17/64" end mills plunge all the way through on both sides, and then I'll use a 7mm reamer plunging only through one side all while using plenty of cutting oil. That's just my method of doing that particular task.
    At the factories were they manufactured AK's they usually don't make sure they're set up is leveled, ridged, or square so the original hole can be difficult to machine it the exact same way. I found that leveling the trunnion and receiver isn't a reliable way to drill barrel pin hole. It's best to align the spindle with the hole of the breach block a lot of builders complain about drilling into virgin trunnions and barrel components. I'd prefer to use virgin AK parts cause you can make sure that you're drilling the holes correctly and not have to worry about egging the damned holes.
    I haven't done many and wanted to set up and drill all the way through from one side. If I am not mistaken that is why it was recommended to line up the trunnion hole, mill 1/2 way through, flip the barreled trunnion over, align the trunnion hole again and mill through. Then ream. The original barrel pin hole will not "egg" if done this way.

  16. #15
    Senior Member

    Member #
    21317
    Join Date
    Mar 2012
    Location
    north central pa
    Posts
    2,856
    Liked
    2720 times
    blue ive got the same lathe. receipt from 1958 i think. my grandfather bought it new.
    barrel pin.. this probably isnt as exact as forbus method but is simpler and i think does a good job.
    pin sticking up out of the trunnion that is a pretty tight hand fit.
    put the barrel in v-blocks.
    i put a 1/4" dowel in the collet. (just the chuck end of a cut off reamer that was junk)
    make the pin and dowel parallel to eachother in x and y axis by tipping the v-block and or turning the barrel in the v-block.
    i use a 1/4" carbide end mill NOT centered. i put it close to the bottom of the hole this way there isnt much to ream.
    watch progress up through the hole w/ a mirror.
    ream from same side.
    i think you could adapt this to a drill press fairly easy.
    as for drilling from both sides it doesnt seem like a good idea on the chamber journal to me.
    and leaving the trunnion flat on a surface may work well most of the time but eventually i promise youll find the trunnion hole that is very crooked.
    Last edited by BR7.62; 06-18-2017 at 09:33 PM.
    PumpStation666 and Longshot1 like this.
    07 ffl


 

 
Page 1 of 2 1 2 LastLast

Sponsors

Posting Permissions

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

Similar Threads

  1. drilling barrel pin
    By BR7.62 in forum Build It Yourself
    Replies: 12
    Last Post: 03-13-2016, 07:21 PM
  2. Replies: 14
    Last Post: 12-30-2014, 05:34 PM
  3. Drilling pin holes in the barrel.
    By Panzer in forum Build It Yourself
    Replies: 9
    Last Post: 03-01-2013, 12:36 PM
  4. drilling barrel pin hole
    By restoreit1 in forum Build It Yourself
    Replies: 8
    Last Post: 01-26-2011, 12:15 AM
  5. Drilling new barrel pin???
    By mustang67 in forum Build It Yourself
    Replies: 4
    Last Post: 12-04-2007, 01:25 PM

Search tags for this page

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