The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > The Smithy

Reply
 
Thread Tools Search this Thread
Old September 6, 2010, 11:50 AM   #1
TrueBrit
Member
 
Join Date: April 27, 2006
Location: canton ohio
Posts: 28
drilling and tapping the yugo m48

any tip on drilling the front part of a yugo M48
__________________
WHEN YOU CARE ENOUGH TO SEND THE VERY BEST
TrueBrit is offline  
Old September 6, 2010, 11:51 AM   #2
TrueBrit
Member
 
Join Date: April 27, 2006
Location: canton ohio
Posts: 28
what i meant was the front part of the receiver
__________________
WHEN YOU CARE ENOUGH TO SEND THE VERY BEST
TrueBrit is offline  
Old September 6, 2010, 12:25 PM   #3
HiBC
Senior Member
 
Join Date: November 13, 2006
Posts: 8,274
Are you thinking of a do it myself project?I do not intend to be disrespectful,but find a gunsmith who has a vertical milling machine such as a Bridgeport.
It is not that it is a difficult job,it is pretty simple.There are a surprising number of ways it can be messed up badly
I can't teach you here.
HiBC is offline  
Old September 6, 2010, 12:31 PM   #4
TrueBrit
Member
 
Join Date: April 27, 2006
Location: canton ohio
Posts: 28
ive already drilled the blind holes i have the right tools for the job just my first one is a bit nerve racking!!!!
__________________
WHEN YOU CARE ENOUGH TO SEND THE VERY BEST
TrueBrit is offline  
Old September 6, 2010, 12:49 PM   #5
Scorch
Senior Member
 
Join Date: February 13, 2006
Location: Washington state
Posts: 15,248
Use a milling machine.
Align the receiver to the X axis of the mill.
Center the tool over the receiver.
Use a carbide drill.
Use a fixture/jig if you like.
Tap carefully, the receiver is surface hardened.
__________________
Never try to educate someone who resists knowledge at all costs.
But what do I know?
Summit Arms Services
Scorch is offline  
Old September 6, 2010, 12:52 PM   #6
HiBC
Senior Member
 
Join Date: November 13, 2006
Posts: 8,274
OK.The first thing you need to do is get set back up where ever you drilled the hole,and you need to be exactly centered over the hole.I use a tap wrench that has a floating dowel pin in the back end of it.The dowel goes in the machine spindle.In this way the tap wrench spins around the dowel,and is free to travel up and down with the tap.It is critical tha the tap goes in straight and centered and stays that way.Lean it over just a little and it will break.
Use a good tap lubricant.I like Rapid-Tap or Tap Magic;About every 1/4 turn of progress,back the tap out a bit more than 1/4 turn to break off the chip.At least a few times per hole,take tha tap all the way out and clear all the chips out.The chips binding up is another way to snap a tap.When you begin cutting with a new,sharp tap,you will feel a certain torque requirement and a small amount of spring in rotation.Be sensetive to that feel.Any increase in torque or spring is danger.Use extreme cautiion with the chips when using the bottom tap. Good luck.
HiBC is offline  
Old September 6, 2010, 06:20 PM   #7
TrueBrit
Member
 
Join Date: April 27, 2006
Location: canton ohio
Posts: 28
i have a forester jig holding it in place so i am all lined up but the taps just dont seem to be biting that good and they are brand new taps.
__________________
WHEN YOU CARE ENOUGH TO SEND THE VERY BEST
TrueBrit is offline  
Old September 6, 2010, 09:32 PM   #8
HiBC
Senior Member
 
Join Date: November 13, 2006
Posts: 8,274
OK,so you are drilling and tapping through a bushing,and I assume you had a bushing sized for the tap drill,and you have changed bushings to allow the tap to go through.Do use an appropriate bushing to guide the tap.
Assuming you have the right size tap drill,I will ask,was your tap drill made of High speed steel or carbide?If you did not need carbide to drill the reciever,then a regular high speed tap should have no hardness issue.
Case by case,generally in my experience Mausers are spot hardened where they need to be hard,but the receiver rings are (to my knowledge) not generally case hardened.
So,now look at your tap.Is it a taper tap,a starter tap,with a long taper on the tip?Might the tip be contacting the bottom of the hole?That sure can be an issue on a shallow blind hole.Then,do you have a plug tap and a bottom tap?Try the plug tap.Does it bite? you won't get real far before you find the bottom.You can get in real trouble when you contact the bottom.Beware of chips,and feel for contacting the bottom.Then come back with the bottom tap,that square ended one,to finish.It is easy to chip off the lead tooth.Don;t.and if you do,it may lock up the tap.If that happens,stop,write us again.
Sometimes there is an advantage to grinding the non-cutting useless part of the tip of the tap off.Clear the chips often.
HiBC is offline  
Old September 7, 2010, 12:09 PM   #9
Scorch
Senior Member
 
Join Date: February 13, 2006
Location: Washington state
Posts: 15,248
Quote:
but the receiver rings are (to my knowledge) not generally case hardened.
Mauser receivers are carburized. Not exactly like case hardening, but pretty close.
Quote:
Then,do you have a plug tap and a bottom tap?Try the plug tap.
Quote:
Clear the chips often.
There ya go!
__________________
Never try to educate someone who resists knowledge at all costs.
But what do I know?
Summit Arms Services
Scorch is offline  
Old September 8, 2010, 08:16 AM   #10
Gunplummer
Senior Member
 
Join Date: March 11, 2010
Location: South East Pa.
Posts: 3,364
Use a carbide spot drill or a drill slightly larger than the tap to break through the cased area around the hole. It is only about .015- .020 deep. If you don't the tap is still fighting its way through the thin outer skin. It should appear as a slight chamfer around the hole you already drilled.
Gunplummer is offline  
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 05:33 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2021 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Page generated in 0.07077 seconds with 10 queries