LAPPING LUGS
- Thread starter clc33
- Start date
therifler
Silver $$ Contributor
you do know that the headspace will be compromised when you do this and it is based off the belt ? if you decide to do it.
you will have to headspace off the shoulder. not that is a bad thing, but you will have to fire form you brass to the lenghten chamber . The Rifler
www.therifler.com
you will have to headspace off the shoulder. not that is a bad thing, but you will have to fire form you brass to the lenghten chamber . The Rifler
www.therifler.com
Good call rifler.
Lapping lugs is not a good idea unless you can re-headspace it.
Better options would be a jewel trigger and/or a good bedding job.
Lapping lugs is not a good idea unless you can re-headspace it.
Better options would be a jewel trigger and/or a good bedding job.
Good point Preacher.Preacher said:
I have never tried a 40x trigger but a bedding job would probably help more than the lapping of the lugs. In my opinion lapping is one of the things to do when you are replacing the barrel along with trueing the face and a good recoil lug.
clc33 said:
Clc33,
The advice given by your smith and several competences here is certainly wise. Lapping is a delicate operation who is only to be undertaken when barrel is removed.
-The first reason for this is that lapping compound is easy to deposit on the counter-lugs of the receiver (and exactly where it is needed) than on the Bolt lugs.
The principle of lapping is the abrasive embed in the softer metal to ’grind’ the harder, and bolts are usually harder than receivers.
-Secondly, when lapping ‘from the rear’, there is no control possible on the operation in progress and, if not done carefully, it can end whith not perfectly square-true surfaces, but rather in a quite ‘helical’ form, with more metal lapped out at the beginning of the engagement cycle than on final closing position.
-Thirdly, there is often only a small spot to lap on one particular place of the bearing area, more compound is to be concentrated there, and how can one control that otherwise than from the front?.
-Fourthly, when the operation is performed, all traces of abrasive are to be eliminated.. How would you ensure that without access at front?.
I do not think a slight correcting lapping changes very much to a well made headspace. After a small lapping, headspace then remains well within the gauge tolerances, nearer rgz “Go” trhan ‘No Go”.
If more than a slight lapping is needed, then, it is time to scratch one’s head about the intrinsic qualities of the action.
When I was to lapping lugs, I used a device screwed in the barrel threads of the receiver, with having in the middle a micrometer screw ended by a miniature Nadella thrust bearing coming in contact with the bolt face. I had then a mean of accurate control on the positioning and pressure exerted on the surfaces in contact, and the certainty to have perfectly trued contacts, not “helicoidal” ones. The lenghtwise position of the bolt was precisely controlled and maintained.
My point, FWIW
R.G.C
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