Some rifles have the bolt engaging lugs machined directly into the
barrel itself. I've been informed that some replace barrels in such a
system by cutting off the lugged section of the old barrel and
threading that onto a new one. Is it really that difficult to
directly machine lugs onto a new barrel and thus eliminate this
creation of a third part, a barrel extension AR 15 style? Can this
replication of the original barrel be done by a home machinist? What
process and tools would be involved, perhaps some internal grooving
and metal shaper work to cut the lugs or is it much more involved?
Any perspective on this would be appreciated. Thanks.

In article 3fd333a7-0b99-4d89-8b66-c6fbe8199dd5
@n38g2000prl.googlegroups.com, says...
Some rifles have the bolt engaging lugs machined directly into the
barrel itself. I've been informed that some replace barrels in such a
system by cutting off the lugged section of the old barrel and
threading that onto a new one. Is it really that difficult to
directly machine lugs onto a new barrel and thus eliminate this
creation of a third part, a barrel extension AR 15 style? Can this
replication of the original barrel be done by a home machinist? What
process and tools would be involved, perhaps some internal grooving
and metal shaper work to cut the lugs or is it much more involved?
Any perspective on this would be appreciated. Thanks.


Easy. Just machine a groove the size of the locking lugs in the barrel
and then cut notches to clear the locking lugs when the bolt is opened.
But, the devil is in the details. How much clearance, exactly where are
the lugs when the bolt is open, how to get everything concentric and
aligned with the bore and so on. You will need chambering reamers and
head space gages. Except for machining the locking groove nearly
everything could be done by hand, if you wanted to; but it takes a lot
longer.

The reason they cut off the old barrel and thread it is money. Probably
a day, maximum, to make a new barrel that way versus, maybe, three days
to cut the locking lugs into a new barrel.

Years ago I built something similar, an interrupted thread locking
single shot action. Took me a while.

--
Cheers,

Bruce in Bangkok

"Bruce in Bangkok" wrote in message
...
In article 3fd333a7-0b99-4d89-8b66-c6fbe8199dd5
@n38g2000prl.googlegroups.com, says...
Some rifles have the bolt engaging lugs machined directly into the
barrel itself. I've been informed that some replace barrels in such a
system by cutting off the lugged section of the old barrel and
threading that onto a new one. Is it really that difficult to
directly machine lugs onto a new barrel and thus eliminate this
creation of a third part, a barrel extension AR 15 style? Can this
replication of the original barrel be done by a home machinist? What
process and tools would be involved, perhaps some internal grooving
and metal shaper work to cut the lugs or is it much more involved?
Any perspective on this would be appreciated. Thanks.


Easy. Just machine a groove the size of the locking lugs in the barrel
and then cut notches to clear the locking lugs when the bolt is opened.
But, the devil is in the details. How much clearance, exactly where are
the lugs when the bolt is open, how to get everything concentric and
aligned with the bore and so on. You will need chambering reamers and
head space gages. Except for machining the locking groove nearly
everything could be done by hand, if you wanted to; but it takes a lot
longer.

The reason they cut off the old barrel and thread it is money. Probably
a day, maximum, to make a new barrel that way versus, maybe, three days
to cut the locking lugs into a new barrel.

Years ago I built something similar, an interrupted thread locking
single shot action. Took me a while.

--
Cheers,

Bruce in Bangkok

That's how Newton built his rifles, actually turning the locking threads in
both the barrel and in the bolt. I've read that Weatherby did the same thing
but I always thought that they actually milled the thread in the bolt. Maybe
Gunner knows.

Newtons were fine pieces of craftsmanship. I missed a chance to buy one 20
years ago.

--
Ed Huntress

trg-s338 wrote:

Some rifles have the bolt engaging lugs machined directly into the
barrel itself. I've been informed that some replace barrels in such a
system by cutting off the lugged section of the old barrel and
threading that onto a new one. Is it really that difficult to
directly machine lugs onto a new barrel and thus eliminate this
creation of a third part, a barrel extension AR 15 style? Can this
replication of the original barrel be done by a home machinist? What
process and tools would be involved, perhaps some internal grooving
and metal shaper work to cut the lugs or is it much more involved?
Any perspective on this would be appreciated. Thanks.


Okay, we get a bit of headspace. Lots of headspace could be a real issue, did the bolt
lug set back or the reciever recess set back, was it overloaded? The typical repair for a
barrel is to screw it off, turn shoulder of barrel the proper amount and put it back on.
Barrels with iron sights need setting it back farther and then a ream job.

Putting the lug recesses in the barrel is doable though. I'd make the bolts with long
lugs and select fit them. Enough lug and you can grind it back to fit.

Repairs would be bitch though if you had lug setback and the rifle wasn't ruined. I'm not
sure I'd want to shoot a bolt that had been tig'd.


Wes



--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

trg-s338 wrote in news:3fd333a7-0b99-4d89-8b66-
:

Some rifles have the bolt engaging lugs machined directly into the
barrel itself. I've been informed that some replace barrels in such a
system by cutting off the lugged section of the old barrel and
threading that onto a new one. Is it really that difficult to
directly machine lugs onto a new barrel and thus eliminate this
creation of a third part, a barrel extension AR 15 style? Can this
replication of the original barrel be done by a home machinist? What
process and tools would be involved, perhaps some internal grooving
and metal shaper work to cut the lugs or is it much more involved?
Any perspective on this would be appreciated. Thanks.

A dumb(?) question he Are the Lugs you're talking about the one(s) on
the *outside* of the barrel that take the bolts/screws that attach the
stock?

Normally, those would be the only ones *on* a barrel as opposed to the
Locking Lugs on the Bolt.

If you're talking about the recesses machined into the barrel that
*receive* the bolt's locking lugs, the operation would, normally, be
performed at the time that the chamber is bored.

Attempting to "splice" a barrel would require an absolutely perfect match-
up between the rifling of the two pieces - the retained chamber section and
the new barrel section.

On Sep 4, 7:19 pm, "RAM³" wrote:
trg-s338 wrote in news:3fd333a7-0b99-4d89-8b66-
:

Some rifles have the bolt engaging lugs machined directly into the
barrel itself. I've been informed that some replace barrels in such a
system by cutting off the lugged section of the old barrel and
threading that onto a new one. Is it really that difficult to
directly machine lugs onto a new barrel and thus eliminate this
creation of a third part, a barrel extension AR 15 style? Can this
replication of the original barrel be done by a home machinist? What
process and tools would be involved, perhaps some internal grooving
and metal shaper work to cut the lugs or is it much more involved?
Any perspective on this would be appreciated. Thanks.

A dumb(?) question he Are the Lugs you're talking about the one(s) on
the *outside* of the barrel that take the bolts/screws that attach the
stock?

Normally, those would be the only ones *on* a barrel as opposed to the
Locking Lugs on the Bolt.

If you're talking about the recesses machined into the barrel that
*receive* the bolt's locking lugs, the operation would, normally, be
performed at the time that the chamber is bored.

Attempting to "splice" a barrel would require an absolutely perfect match-
up between the rifling of the two pieces - the retained chamber section and
the new barrel section.

RAM: To clarify, I meant to say that the "recesses machined into the
barrel that receive the bolt's locking lugs", as pertaining to my
inquiry. Apologies for the inaccuracy of terminology. So the reaming
of the chamber would be done first and the dimensional machining of
the recesses done next to get it as close as possible to the proper
headspace?

Ed Hunter, Bruce from Bankok: That is an interesting twist (pun
intended) on the locking lug design, but how would limit the tightness
of the bolt lock on the head of the brass (headspace)? I seem to
recall somewhere a post on a threaded bolt with flats ground on
opposite sides to allow withdrawal of the bolt, as I understand it.
Was that from you Bruce?

ksdg another poster, references the "old Savage bolt action 23A, the
barrel and receiver were made out of one piece of steel. There was no
joint between barrel and receiver. They seemed to shoot very
accurately." A variation in design that would indeed promote
alignment and rigidity in the system but probably not a good system
for barrel burner cartridges.

I suppose headspacing adjustments on a recessed barrel would be a
matter of grinding and lapping the lugs until a perfect fit is
acquired on the gauges. The design of current Savage bolt action with
the barrel screwed in or out to achieve perfect headspace and then
lock ringed in place is looking more and more a convenient and
practical design, accurate too from what I've read. I'm just not
clear on how the "moveable bolt head" contributes to the accuracy
potential of the design.

This is what I was thinking of when I saw the header,
http://www.landingnewjersey.com/novelty.htm


--
Stupendous Man,
Defender of Freedom, Advocate of Liberty

On Sep 5, 10:02 am, "Stupendous Man" wrote:
This is what I was thinking of when I saw the header,http://www.landingnewjersey.com/novelty.htm

--
Stupendous Man,
Defender of Freedom, Advocate of Liberty

Bunch o' sadfaced lugs they are, really bummed!

In article 55dd6f19-d3f4-43f3-b07c-d85b5c144639
@v39g2000pro.googlegroups.com, says...
On Sep 4, 7:19 pm, "RAM³" wrote:
trg-s338 wrote in news:3fd333a7-0b99-4d89-8b66-
:

Some rifles have the bolt engaging lugs machined directly into the
barrel itself. I've been informed that some replace barrels in such a
system by cutting off the lugged section of the old barrel and
threading that onto a new one. Is it really that difficult to
directly machine lugs onto a new barrel and thus eliminate this
creation of a third part, a barrel extension AR 15 style? Can this
replication of the original barrel be done by a home machinist? What
process and tools would be involved, perhaps some internal grooving
and metal shaper work to cut the lugs or is it much more involved?
Any perspective on this would be appreciated. Thanks.

A dumb(?) question he Are the Lugs you're talking about the one(s) on
the *outside* of the barrel that take the bolts/screws that attach the
stock?

Normally, those would be the only ones *on* a barrel as opposed to the
Locking Lugs on the Bolt.

If you're talking about the recesses machined into the barrel that
*receive* the bolt's locking lugs, the operation would, normally, be
performed at the time that the chamber is bored.

Attempting to "splice" a barrel would require an absolutely perfect match-
up between the rifling of the two pieces - the retained chamber section and
the new barrel section.

RAM: To clarify, I meant to say that the "recesses machined into the
barrel that receive the bolt's locking lugs", as pertaining to my
inquiry. Apologies for the inaccuracy of terminology. So the reaming
of the chamber would be done first and the dimensional machining of
the recesses done next to get it as close as possible to the proper
headspace?

Assuming you are building a one off, you first fit the barrel to the
action, or you machine locking recesses into the rear of the barrel.
Then you cut the chamber to the proper depth with whatever breaching is
used. In a production setup you would simply machine each part to
specifications.


Ed Hunter, Bruce from Bankok: That is an interesting twist (pun
intended) on the locking lug design, but how would limit the tightness
of the bolt lock on the head of the brass (headspace)? I seem to
recall somewhere a post on a threaded bolt with flats ground on
opposite sides to allow withdrawal of the bolt, as I understand it.
Was that from you Bruce?


The interrupted "thread" design originated, I believe, in large cannon -
navel guns. The thread is fairly shallow in pitch and the locked
position is determined by a stop, the shank of the bolt handle usually
so the closed position is predetermined. Your description of a bolt with
flats on it (with corresponding grooves in the nut) is a good
explanation of how they work.

ksdg another poster, references the "old Savage bolt action 23A, the
barrel and receiver were made out of one piece of steel. There was no
joint between barrel and receiver. They seemed to shoot very
accurately." A variation in design that would indeed promote
alignment and rigidity in the system but probably not a good system
for barrel burner cartridges.

If I'm not wrong the 23A was a .22 rimfire and (I believe) the 23B was a
25-20 or other small round. I suspect that the locking was simple the
bolt handle.

--
Cheers,

Bruce in Bangkok