ASSRA Forum › General › Gunsmithing Single Shot Rifles › unertl rear scope mount problem
(Moderator Group: Moderator)
‹ Previous Topic | Next Topic ›
Page Index Toggle Pages: 1 Send TopicPrint
Normal Topic unertl rear scope mount problem (Read 2523 times)
dick_eesley
Ex Member


unertl rear scope mount problem
Sep 5th, 2010 at 11:47am
Print Post  
Had to leave fall ASSRA matches due to a faulty posi rear scope mount which would'nt tighten  experts there surmised stripped threads    can I dare tap the mount with 6-40 tap??   also 6-40 screw in bad shape and needs replacement  seems the 6-40 screws moves freely in the larger od threaded piece  is this normal   been using the scope mounts for thirty years    any solutions   dick eesley
dick eesley@yahoo.com
  
Back to top
 
IP Logged
 
SteveC
Full Member
***
Offline



Posts: 105
Location: Tacoma
Joined: Aug 16th, 2007
Re: unertl rear scope mount problem
Reply #1 - Sep 6th, 2010 at 12:12pm
Print Post  
Sounds like a job for a Heli-Coil.It looks like a coil spring with a diamond shaped cross-section. You drill out the hole to the pitch diameter of the original screw and tap with an oversize tap. Then screw in the Heli-coil and break off the insertion tab. Stronger than the original. You should be able to find them at auto parts or industrial supply stores. Hope this helps.
                                           Steve
  
Back to top
 
IP Logged
 
40_Rod
Frequent Elocutionist
*****
Offline


Extremism in the persuit
of accuracy is not a
vice

Posts: 4285
Location: Knoxville, TN
Joined: Apr 20th, 2004
Re: unertl rear scope mount problem
Reply #2 - Sep 7th, 2010 at 8:08am
Print Post  
The problem is getting to it. the stripped thread is in the rear mount. The hole could be drilled from the front but then getting the heli coil in would be imposible. The best way to fix it would be to make up a new screw on a larger screw.

40 Rod
  
Back to top
 
IP Logged
 
bulldog1935
Ex Member


Re: unertl rear scope mount problem
Reply #3 - Sep 7th, 2010 at 3:58pm
Print Post  
a helicoil requires an even larger drilled and tapped hole for a smaller screw thread.  Just going up one size in screw with a new bottom-tapped thread makes the most sense - it's the smallest hole to solve your problem.
  
Back to top
 
IP Logged
 
Page Index Toggle Pages: 1
Send TopicPrint
‹ Previous Topic | Next Topic ›
 
  « Board Index ‹ Board Top  

ASSRA Forum » Powered by YaBB 2.6.12!
YaBB Forum Software © 2000-2026. All Rights Reserved.

Valid RSS Valid XHTML Valid CSS Powered by Perl Source Forge

Page completed in 0.9201 seconds.