Lapping bolt lugs on a Rem700

H

huntinfool

Guest
I get the gist of it, but what/where do I buy the lapping compound?

Also, my gunsmith told me if only one lug is touching, I can remove the highest side with a "finish file"???

So exactly what is a "finish file"?
 
I think you are best to leave it alone.. if the lugs are bad you should have them machined and the lug recesses machined... then no lapping is required at all and the surfaces are true. Lapping can not do that...
 
Judging from the questions you’ve asked I say you had better leave things alone. If your bolt lugs and receiver abutments are that far out you will create a serious headspace problem if you start filing on bolt and trying to lap them in. To do this sort of job correctly you need the proper tools and equipment to remove the barrel, true the receiver abutments, true the bolt lugs and square the bolt and receiver face. Then you will need to set back the barrel to correct the headspace. To perform these tasks without the proper tools, knowledge, skill and ability is inviting disaster!

You wouldn’t fill your own teeth would you?
Nic.
 
True the action, you won't look back

I've spent four years as an apprentice toolmaker filing every day for several hours in tolerances of 0.02mm (.0008"). If I would have to file one locking lug true with the other, the bolt the receiver recess and the bolt/receiver face I won't be able to do so. So what an imbecile if he can tell an average bloke to do that. Listen to Dennis and have at least the bolt face/lugs and the locking recess and the front of the receiver squared if not going to the whole action truing process.

Shoot well
Peter
 
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Well, the guy who told me this was Gordy Gritters. He said removing just enough metal so both lugs made contact would be fine. He suggested first to try lapping them, but it was faster (if the one lug was excessive) to lightly file it.
 
I'd suggest that you use a fine "India" stone rather than a file. It will be much easier to control and metal removal rate is a lot less. I probably have about 100-150 different files and use them often but stones are a better choice for many tasks.
Lapping compounds differ in types, use and abrasive size. Brownells has a good selection if you want to go that route.
 
lapping vs headspace

The difference between the go and no go on headspacing is .003- .004 "
Now if your rifle is headspaced on the lug that is making contact and you remove material to try to even the lug contact pretty much gaurantees an excessive headspace situation.

I have seen lots of guys bugger up their rifle with minium knowledge and lots of lapping compound!

Chris
 
One important point is that, on a Remington 700, the lugs will often show evidence that the lower lug is contacting while the upper is not. The reason for this is that the rear of the bolt is lifted by the pressure of the sear on the cocking piece when the chamber is empty. Most actions are cycled more with the chamber empty than loaded. So the contact evidence is deceiving.
Uneven contact is fairly common on the Remingtons and seems to be due to misalignment of the bolt head when it was brazed in place. So, if the lugs are misaligned, so is the bolt face. You are as well off to remachine everything and correct all deficiencies at once.
Having said that, lapping was once considered SOP when building a rifle and most accuracy gunsmiths did it. I did, Dennis did, so did Seeley Masker and a host of well know old masters. It is still a viable method of improving contact and surface finish but it is not a good way to correct serious misalignment.
It is entirely possible to file or stone a lug to equalize contact but to do so successfully takes considerable skill.
Lapping compounds are available from Brownells.
When lapping, remove the striker assy. Try and wrap a layer of paper around the bolt within the bridge so the bolt is better aligned. Maintain rearward pressure with a nylon stub which threads into the receiver or by placement of a plastic shim im the counter bore of the barrel. I use a stub which centers the bolt on the threads whilst providing rearward pressure. Avoid springloaded fixtures as a spring fixture will perpetuate an error.
Just don't go filing down the lower lug to correct a misalignment which isn't there! Regards, Bill
 
Using a File on locking lugs is nuts !
You need to find a Gunsmith not a Blacksmith.

How do you plan to keep everything Flat, Square, and Parallel while you are scratching away on the lug with a K-Mart file or a stone ?? Get back to us on that.
 
I have commented on this before. It is entirely possible to file and hone something which is flat, square, parallel and perfectly finished. If you ever get a chance to look at one of Martin Hagn's falling block actions, you will see some beautiful examples of this. I'm sure you could make a bunch of actions from the filings Martin has produced over the years. As I said, it requires a certain amount of skill which is acquired through experience.
I used to have Remington recoil lugs surface ground. They were still often no better than .0005 parallel. I can do better than that by hand and do so.
Still, it is important to be sure of what you are trying to accomplish before picking up that file and I don't recommend it as standard procedure. Regards Bill.
 
Finish file-lets be realistic

No offence, but a guy who is asking a question "what exactly is a finish file?" will most likely be unable to do anything accurate with it anyway, regardless of how hard he'll try or how many good tips he'll get. For him lapping is far safer, but it's not the solution to the possible total misalignement.
My advice is:True the action, if not at least listen to Dennis.

Shoot well
Peter
 
Bill Leeper said:
I have commented on this before. It is entirely possible to file and hone something which is flat, square, parallel and perfectly finished. If you ever get a chance to look at one of Martin Hagn's falling block actions, you will see some beautiful examples of this. I'm sure you could make a bunch of actions from the filings Martin has produced over the years. As I said, it requires a certain amount of skill which is acquired through experience.
I used to have Remington recoil lugs surface ground. They were still often no better than .0005 parallel. I can do better than that by hand and do so.
Still, it is important to be sure of what you are trying to accomplish before picking up that file and I don't recommend it as standard procedure. Regards Bill.
Click to expand...

Bill, The person who was grinding your recoil lugs had little knowledge, or poor equipment, or both. There is no reason why a recoil lug cannot be ground flat to within .0002 a most.

George
 
That's right; there is no good reason but operator error rears it's ugly head all too often. The lug is cupped and doesn't sit properly on the magnetic chuck. Or, the lug get put in with a little debris under one side. Or, the operator doesn't let the grind finish. Often, grinding is as much an art as a science.
I once received a lug with a custom action which was out by .0007". When I called and complained I was told, "It can't be; those things are surface ground."
I sent it back anyway and received a replacement which was perfect. I only mentioned the surface grinding error by way of illustrating that machines are not always the final answer and good work is possible by hand. Recommended as a standard practice? I would say not but it's a possibility.
 
huntinfool said:
I Also, my gunsmith told me if only one lug is touching, I can remove the highest side with a "finish file"???

So exactly what is a "finish file"?
Click to expand...

A Finish file is like a Swedish file... only a little farther East. :confused: :D:D
 
Lapping Lugs

I spent quite a bit of my younger years filing large foundation "chocks" that went under the mounting pads of large reduction gears and engins in Tug Boats. It is a lost art, they use poured epoxie chocks now.
So, I know how to use a file. If you do not, the best thing to do is leave the file in the drawer.
When checking your lugg contact with prussian blue, always push the stripped bolt forward when closing it, then, when it is close, push the bolt back against the lug abutments to get an impression. Then, push it back forward, and turn it open. That way, you get a true impression when the bolt is closed and in battery, not 'wipe".
If you have a lugg that is really out, (most are not as bad as many suspect), place lapping compound on that lugg only, sort of roughing it in. Don't put any on the other lug untill both show some contact.
.If you do not have a tool that pushes the bolt straight back while lapping, get one. If you can't get one, then send it to some one else who has the proper tools.
Even with the proper tools, lapping lugs in actions that have a lot of bolt to raceway clearance is an iffy proposition at best. Sometimes you end up with a worse off situation than when you started........jackie
 
Dusty Steven

PPP MMM said:
I've spent four years as an apprentice toolmaker filing every day for several hours in tolerances of 0.02mm (.0008"). If I would have to file one locking lug true with the other, the bolt the receiver recess and the bolt/receiver face I won't be able to do so. So what an imbecile if he can tell an average bloke to do that. Listen to Dennis and have at least the bolt face/lugs and the locking recess and the front of the receiver squared if not going to the whole action truing process.

Shoot well
Peter
Click to expand...
,,,,,,,,,,,,,,

Where did I said it's OK to file a lug true?

Shoot well
Peter
 
Hey Peter...

Lets leave that one alone and just listen to what Jackie has to say.

Sooner or later truing the bolt to the action is an accuracy requirement, yes?

Unless you have a CNC and its true from the get go... then is the firing pin concentric..or is it eccentric..;)

:D:D:D
 
Dusty Stevens said:
I wish these actions had a way of letting me know a blacksmith has worked on them before I buy em
Click to expand...
Look for horseshoe nail decorations in the stock. :rolleyes:

I once knew of a chap who had a rifle headspaced too tight, so one of his expert friends ground off the lugs for him. It didn't seem to bother him that when you take too big a chunk off, you'll end up with a less than optimally timed action, as well as excess headspace, or as it's known in some circles, a junker.
 
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