Bolt Lapping - M14 Forum

M14 Forum


Bolt Lapping

This is a discussion on Bolt Lapping within the Gunsmithing forums, part of the M14 M1A Forum category; Finally got around to looking at an action and I think this is the most lapping I have seen on any of my builds. The ...


Go Back   M14 Forum > M14 M1A Forum > Gunsmithing

7Thanks
  • 1 Post By behr70
  • 1 Post By tonyben
  • 2 Post By JayKosta
  • 1 Post By tonyben
  • 2 Post By nf1e
Reply
 
LinkBack Moderator Tools Display Modes

Old February 2nd, 2017, 01:12 PM   #1
Platoon Commander
 
Join Date: Nov 2003
Location: ID
Posts: 472
Bolt Lapping

Finally got around to looking at an action and I think this is the most lapping I have seen on any of my builds. The side to side fit must have been tight on this one? Or maybe I do not pay to much attention?
Attached Images
File Type: jpg IMG_0900.jpg (28.6 KB, 80 views)
File Type: jpg IMG_0901.jpg (28.0 KB, 80 views)

Thanks from tonyben
behr70 is offline  
Remove Ads
Old February 2nd, 2017, 01:15 PM   #2
Super Moderator
 
Phil McGrath's Avatar
 
Join Date: May 2004
Location: Silverdale, WA.
Posts: 7,632

Awards Showcase

What was the bolt and receiver combo? and just how did you lap it?

Phil McGrath is offline  
Old February 2nd, 2017, 01:16 PM   #3
Platoon Commander
 
Join Date: Nov 2003
Location: ID
Posts: 472
TRW and LRB, I did not perform work.

behr70 is offline  
 
Old February 2nd, 2017, 01:18 PM   #4
Super Moderator
 
tonyben's Avatar
 
Join Date: Apr 2007
Location: Beaverton, OR
Posts: 9,180

Awards Showcase

I have seen bolts fit tight and I do get results like you show sometimes.

Tony.

Thanks from behr70
tonyben is online now  
Old February 2nd, 2017, 01:21 PM   #5
Platoon Commander
 
Join Date: Nov 2003
Location: ID
Posts: 472
Tony, good to know, I was swapping commercial bolt internals for GI and noticed the lapping. Checked the remainder of the heard and lugs only, and not into the bolt side. I guess this one is now special.

behr70 is offline  
Old February 2nd, 2017, 01:36 PM   #6
Lifer
 
JayKosta's Avatar
 
Join Date: Mar 2009
Location: Endwell NY
Posts: 2,188
Without using 'lay-out fluid' or magic marker, it's not possible to see how much actual contact area is present with the receiver.

Yes those bolt lugs have been fully dressed/polished, but that's only part of the lockup.

If you do try using the fluid/marker, be sure to coat the surfaces on the bolt AND receiver and check both for seeing the contact areas.

Jay Kosta
Endwell NY USA

Thanks from behr70 and m1sniper
JayKosta is online now  
Old February 2nd, 2017, 01:37 PM   #7
Super Moderator
 
tonyben's Avatar
 
Join Date: Apr 2007
Location: Beaverton, OR
Posts: 9,180

Awards Showcase

LRB's run a little narrow in that area, from what I've seen.

Tony.

Thanks from behr70
tonyben is online now  
Old February 2nd, 2017, 01:51 PM   #8
Dodgin' The Reaper
 
nf1e's Avatar
 
Join Date: Aug 2009
Location: New Preston,CT
Posts: 7,133
I have an M25/TRW build done by LRB that shows almost identical side contact lapping. Rifle now has 3500 rounds through it and no problems so far.

Thanks from behr70 and tonyben
nf1e is online now  
Old February 3rd, 2017, 07:06 AM   #9
Lifer
 
JayKosta's Avatar
 
Join Date: Mar 2009
Location: Endwell NY
Posts: 2,188
Thanks for the info about 'part fitting' to give 'clearance' with some part combinations.

I usually think of 'bolt lug lapping' as being done to increase/equalize the amount of 'pressure bearing' surfaces. But I can certainly see the need for 'fitting' it there is too much contact/rubbing in unwanted areas.

Jay Kosta
Endwell NY USA

JayKosta is online now  
Old February 3rd, 2017, 07:31 AM   #10
Super Moderator
 
tonyben's Avatar
 
Join Date: Apr 2007
Location: Beaverton, OR
Posts: 9,180

Awards Showcase

Quote:
Originally Posted by JayKosta View Post
Thanks for the info about 'part fitting' to give 'clearance' with some part combinations.

I usually think of 'bolt lug lapping' as being done to increase/equalize the amount of 'pressure bearing' surfaces. But I can certainly see the need for 'fitting' it there is too much contact/rubbing in unwanted areas.

Jay Kosta
Endwell NY USA
I've also seen contact at the rear safety lug under the cartridge clip guide. If I can't see daylight there, I add a dab of lapping compound there when I do bolt lug lapping.

tonyben is online now  
Old February 12th, 2017, 06:30 AM   #11
Lifer
 
tokiwartooth's Avatar
 
Join Date: May 2011
Location: Northport, NY
Posts: 2,613
Never let lapping compound migrate out like that. You're using too much. Just need a little and keep it at the lugs. If the bolt pops out while lapping clean everything up, mark everything up again and apply lapping compound in the receiver areas only.

tokiwartooth is offline  
Reply

  M14 Forum > M14 M1A Forum > Gunsmithing


Search tags for this page

m14 bolt lapping

Click on a term to search for related topics.

Moderator Tools
Display Modes


Similar M14 Forum Discussions
Thread Thread Starter Forum Replies Last Post
M14 Bolt Lug Abutment Geometry jywolfe Gunsmithing 8 January 25th, 2015 03:50 PM
Bolt lapping MemphisMachinists The M14 22 May 13th, 2011 11:18 AM
762MM Bolt Evaluation ripsaw The M14 18 February 13th, 2011 04:09 PM
M1A bolt lapping instructions art luppino Art Luppino 1 January 2nd, 2007 12:06 AM
M1A bolt lapping instructions art luppino Reference 0 January 1st, 2007 11:13 AM



Top Gun Sites Top Sites List