Relining a barrel

[augercreek]

What all is involved in relining a rifle barrel? If you have a drill bit long enough and a lathe to turn the barrel what more is needed? It doesn't seem to be that complicated.

[Ballistics in Scotland]

An ordinary twist drill? These are extremely likely to wander unacceptably far off centre in the length of a rifle barrel. You really need some sort of piloted tool, and the best way is to search on eBay for pilot drill, counterbore etc.. to see pictures which can give you ideas. Some counterbores - not all = fulfill the two necessities of accepting a detachable pilot, and allowing clearance of chips to the rear, and being of high speed steel with a small diameter shaft, so that they can be silver soldered to an extension rod.

Redman sell a twist drill (I think only in 8mm for .22 and 13mm. for larger liners) which is reduced to act as its own pilot. These are only long enough to reach the middle from each end, which I don't like, and TJ's liners, which offer a bigger variety than Brownells, are sized in sixteenths of an inch, not millimetres.

I have heard people suggesting that you can ream the bore larger by using two or three adjustable reamers in succession, but I don't fancy trying this. They seldom ream well, still need the extension, and aren't high speed steel. I think they might break off, at the worst possible time of course, if the shank is annealed by soldering.

If you want to rely on an unpiloted drill, which may follow the bore if the difference in diameter isn't too great, you should rig up a chuck or other holding device on the left-hand end of the headstock. and true up the bore in line with the axis of rotation. You don't need the high-pressure forced feed of coolant which you do for deep drilling from scratch. But you do need to remove the tool and clear the chips frequently, and squirt coolant or lubricant in by hand. Don't let the barrel get really hot while you are drilling and above all don't stop and leave the drill in there while you go off for a cup of coffee. It may shrink and grip the drill, especially a carbide one.

[leadman]

I relined a Meridan 22cal. rolling block about a year ago. I was fortunate as I was lent the drill and 22 short reamer. I had ordered a liner from Midway but after the second liner I got a refund. Very poor quality.
I bought a TJ liner and it made me very happy as it is very high quality. The drill I used was a long shank but I have been told a short shank drill can have a piece of rod soldered or brazed to it must must be done so it is perfectly inline.
I used a cordless drill to power the drill which worked fine. I had to make many stops, remove the drill, clean the bore and drill, reoil an drill some more. Took me almost 3 hours to get the barrel drilled. I was being especially careful as the drill was not mine.

[Ballistics in Scotland]

Well, you can't store hours away somewhere, and save them for something else later.

A fairly long shank drill is best even if you want to extend it, as the long flutes will reduce the number of times you have to remove and clear it. Many drills are softer near the blunt end, and can be turned down in the lathe with a carbide lathe tool. Particularly for larger calibres you may be able to find a drill with a reduced shank end. But if you are drilling a large caliber to 5/8in. (the commonest size) you would probably find that drilling freehand would be dangerous, as the drill would tend to snatch. Three or four cutting edges should prevent this.

Another issue is what you use to fix the liner in place. It is mostly between soft solder and epoxy. I'd prefer a slow-setting or even special high temperature epoxy for many rifles, but that won't matter for a .22. I have a copy of "The NRA Gunsmithing Guide Updated", which mostly dates from the 1970s, and it recommends the special bearing fitting versions of Loctite, though not the thread-locking variety. I don't know if there is still any advantage in using these. They could "freeze" if there was a pause in sliding the liner home, so you would want to make really sure of the fit.

[marlinman93]

Most gunsmiths who do a good job of relining a bore will drill undersized from each end. Drilling the entire length from one end is asking for trouble. More chance for the drill bit to walk off center as it gets longer into the bore. After drilling undersize, they use a reamer to get the final desired size for the liner. There are those who can put a liner in, but everyone can tell it's relined, and how it shoots is questionable. Then there are those who know how to put a liner in and make the gun shoot better than, or equal to new.
Most gunsmiths today also use Loctite to install liners, as it takes less clearance, which makes the liner harder to see. The new Loctite products hold as well as anything, and give you plenty of time to work with them, if you have your clearances correct. 609 seems to be the choice of most gunsmiths. Need to keep the liner wetted well as it's pushed into the bore.
There are some other tricks to barrel liner installation that some gunsmiths use, and each seems to have his own tricks.

[Ballistics in Scotland]

That is useful information about the Loctite, for which much thanks. Midway list the 609, and there are other grades which might be stronger, and stand 180 rather than 150 degrees centigrade. Strength of the 609 is good enough, though and maybe gunsmiths have found it easier to keep a continuous film throughout the joint.

The NRA article comes from a long time ago. The recommendation that bore reamers can be made from threading taps probably dates it. They do say, though, that if soft solder is deformed by pressure, it will stay deformed, while Loctite is plastic and will bounce back. I'd question whether that really matters, as long as gaps aren't left.


To hide the joint at the muzzle you could crown the liner and gently peen it over the muzzle before finishing it flush - or do the opposite with the muzzle. Or you could ream from the breech with an extended hand reamer, which has about a sixty-fourth of an inch of taper on the end, and allow just enough of that to emerge, to form a light tapping fit at the muzzle while the rest is a smooth running fit. Finally you could achieve the same effect with a thin-walled round barrel by slightly shortening it with a pipe cutter, which depresses the area of the cut slightly.

If you are lining a shotgun barrel and the sizes are right, something like a 5C collet chuck in the lathe would enable you to turn the liner to fit. A good hole is too good to waste. For a 7/16 liner to .410 that should leave ample metal.

[John Taylor]

I do more than a few liners. I use a piloted drill with a shaft added to go the full length of the barrel and a lathe. The hole is drilled under size and a reamer is pulled through the bore. The reamer is set up to have oil feed to flush the chips out and keep it cool. I use an old power steering pump for the oil feed. Reamer is mounted on a tube for the oli. I have made many different size piloted drills by using a tool post grinder in the lathe. Pacific Tool and Gauge makes piloted reamers with interchangeable pilots and they are threaded to take an extension. I have been using 262 Loctite for about 18 years with no problems. I try for .002" clearance which is not enough room for acraglass or epoxy. The end of the barrel can be peened slightly and the liner driven through so when it is crowned the liner can not be seen. I stress the fact that the peening should be very light as you don't want to deform the liner.

[Ballistics in Scotland]

Yes, all that sounds right. I must stress that I am only an amateur, but I would rather use oil for this application than ordinary lathe coolant, which is water-based and not much of a lubricant.

I do like the idea of pulling rather than pushing any cutting tool, as I think it would be likely to go straighter and avoid roughness. It would surely be preferable for anybody who wants to do this with a freehand drill. The snag is that most tools would then require anticlockwise rotation. I have some carbide four-edged backfacing tools which are meant to create a round plane surface around a hole in an inaccessible situation, but while they cut anticlockwise, they don't have chip clearance to cut more than about a quarter inch deep. Something that does, though, would be worth keeping an eye open for.

[marlinman93]

Whether water based, or not; lathe coolant/lubricant works better than oil, as it flushes the chips out much easier than oil. Oil lubricates well, butt can clog up in the bore and scratch the freshly bored hole. Really need to move that stuff out to make it a clean, smooth hole.
It also does a better job of keeping the bit cool, which extends the life of tooling.

[PaulG67]

Brownells has the drills
http://www.brownells.com/gunsmith-tools-supplies/power-tools-accessories/drill-bits/barrel-liner-drills-prod6773.aspx

And liners
http://www.brownells.com/gunsmith-tools-supplies/barrel-tools/barrel-liners/centerfire-barrel-liner-prod10976.aspx

[leadman]

I was visiting a lgs and saw an old Mauser that very obviously had a liner installed in it for a 7 X 57. The clearance at the muzzle was probably .004" or so. I would be very scared of firing this gun.
I fired the Meridan a few times but the pins for the rolling blocks were pretty worn so held off any more firing. Accuracy was decent. I have been sidetracked by way to many projects lately but mean to get it done soon.

[Bad Ass Wallace]

A good source of long shanked cobolt tipped drills

http://www.shars.com/company/online-catalog

[Ballistics in Scotland]

Whether water based, or not; lathe coolant/lubricant works better than oil, as it flushes the chips out much easier than oil. Oil lubricates well, butt can clog up in the bore and scratch the freshly bored hole. Really need to move that stuff out to make it a clean, smooth hole.
It also does a better job of keeping the bit cool, which extends the life of tooling.

That is the situation with drilling a new hole, but machine reamers have a reverse twist, and in an existing bore will push chips ahead of the tool. Oil is fine for that.

[John Taylor]

I have made several reamers for doing rebores and liners. Some will give a good bore and some don't. The best ones I have in the shop at this time are carbide and made by PTG but at $200 apiece I don't have very many. For relines the bore does not need to be as smooth as for a rebore. Most of the time I'm only taking out .010 to .015" with the reamer and the cutting oil does a good job of keeping the chips flowing most of the time.

[Ballistics in Scotland]

For those who feel driven to do relining without a lathe, here is the sort of tool which I think could be used to make a drill to be pulled through the bore, silver soldered into a steel rod. You would have to shorten it to allow clearance of the chips behind the drill, and either the size of the rod itself, or a metal sleeve on it, would act as a pilot. The drill can be as short as you like if you get the pilot right, and the angled edges would make it less likely to snatch than a right-angled counterbore. If you are silver soldering it, with something like Brownells 355, beware of cheap ones which aren't genuine high speed steel.

The only infraction I ever got on this website was for giving the URL of an eBay listing, which I meant purely for informational purposes. But I believe you would find similar tools by searching for "countersink", "pilot" and one of the common makers, "Robert Charles".

Many hand-held electric drills now permit reversed rotation, but you might still have the problem of a right-hand threaded chuck falling off. One way of preventing this would be joining a female-threaded drill to a female-threaded chuck with a piece of threaded rod, and a locknut on it for each component.

165052

[marlinman93]

I wonder if silver soldered connection would hold up under this use? Sure would hate to get part way through a bore and lose it. Also wonder how one would silver solder so close to the cutter, and not affect the temper? Tig might be a much better way to attach a rod for pulling the cutter through.

[Ballistics in Scotland]

That is indeed the problem, and any way you attach a drill is going to demand care in drilling. I think silver solder would hold as long as you find a way a cylindrical part of the tool is inserted into the rod, or vice versa. Especially if shallow flutes remained.

High speed steels are commonly tempered by slow soaking at 500 Centigrade or more, for a recommended working temperature of 600 to 650. Brownells Silvaloy 355 flows at about 646, after melting at a lower temperature. (I suspect that it actually is a Johnson Matthey solder, Silver-flo 55 in the UK but Matti-sil in the US, which is also available in ribbon and foil, although I haven't found out yet if you pay the same extremely large amount for it to be in that form.) It can be done, especially if you apply the heat to the site of the joint, and the edges remain a shade cooler.

Just as an experiment I once MIG welded two pieces of O1 tool steel. It was locally so hardened by the heat and both air and conductive cooling, that the weld broke out of the metal quite easily under stress. I don't know what would happen if you welded high speed steel, but you don't hear of many people doing it.

[Geezer in NH]

When I had my smithing shop I sent the barrel out to the guys who specialize in the reline and added 20%. That saved me from losing 20% doing it in my shop.

[EDG]

Successfully drilling any long deep hole depends on what your hands feel while feeding in the tool.

I would also recommend that after you get the barrel dialed in that you turn it about 50 RPM and look through it to see how crooked it is.
I once worked on a Remington Hepburn barrel that flopped around like a jump rope.
The hole was crooked at least 1/16". That increases the pucker factor when you know the tool has to follow that.

[John Taylor]

Successfully drilling any long deep hole depends on what your hands feel while feeding in the tool.

I would also recommend that after you get the barrel dialed in that you turn it about 50 RPM and look through it to see how crooked it is.
I once worked on a Remington Hepburn barrel that flopped around like a jump rope.
The hole was crooked at least 1/16". That increases the pucker factor when you know the tool has to follow that.
The piloted drill bit will follow a slight curve and the reamer will also. Thin walled barrel may warp quite a bit when drilling, I have thrown out a few shotgun barrels that did not come out as expected. It is easy to straiten barrels in a press before drilling. Every so often I find a barrel that looks strait on the outside but the bore is not strait.

[Ballistics in Scotland]

I've seen barrels like that, notably a Numrich octagonal barrel of long ago, though fortunately none of them were mine. It is a serious fault regardless of relining, as the uneven heat retention is likely to cause a walking group. I wonder if it would be possible to drill piloted in a thin steel tube, small enough to be stretched dead straight in a crooked bore till while a thick layer of soft solder or epoxy solidifies?

[John Taylor]

Had a Japanese match lock come in that someone tried to bore out for a liner and the bore went way off center. Was able to save the back half of the barrel with all the fancy engraving and inlays and made up a boring bar that had the pilot behind the cutter. Once the bore was started true the pilot kept the cutter centered in the bore. The OD was dialed in so the bore was centered when the cut was finished. Then another barrel was turned down to slide into the old half and welded in the middle then machined to match the original contour. This was a smooth bore and the weld caused a tight spot in the middle that had to be reamed and polished. One of those fun projects and the oldest gun I have worked on. Made it shootable again.

[bstone5]

Relined a lot of old 22 rim fire rifles used the drill from Brownells after making it longer.
Drilled in a lathe from both ends. Use the green locktight.

The liners worked well after a chamber was made and a little fire lapping to smoth out the are where the chamber meets the rifling.

To make the gun shoot well a little tapper in the bore helps, the tapper should get tight just at the muzzle. The lapping takes a few hours with a lot of time making new laps from time to time.

Did one for a 78 year old gentleman who wanted to give the rifle he got when very young to his grand son.

Years ago I would soldier in the barrel liner but the new locktight works very well and is easy to work.

[Ballistics in Scotland]

Had a Japanese match lock come in that someone tried to bore out for a liner and the bore went way off center. Was able to save the back half of the barrel with all the fancy engraving and inlays and made up a boring bar that had the pilot behind the cutter. Once the bore was started true the pilot kept the cutter centered in the bore. The OD was dialed in so the bore was centered when the cut was finished. Then another barrel was turned down to slide into the old half and welded in the middle then machined to match the original contour. This was a smooth bore and the weld caused a tight spot in the middle that had to be reamed and polished. One of those fun projects and the oldest gun I have worked on. Made it shootable again.

That sounds like a very worthwhile job. I wonder if the original bore was straight? I'm not surprised by the tightness caused by the welding, and it is a good thing you knew to detect and deal with it. It doesn't sound the sort of thing that could be done with rifled or higher pressure firearms, for I don't know any means of fixing the liner that wouldn't be harmed by the welding temperature. An unwelded join covered by a sling swivel band might be good for some.

[John Taylor]

That sounds like a very worthwhile job. I wonder if the original bore was straight? I'm not surprised by the tightness caused by the welding, and it is a good thing you knew to detect and deal with it. It doesn't sound the sort of thing that could be done with rifled or higher pressure firearms, for I don't know any means of fixing the liner that wouldn't be harmed by the welding temperature. An unwelded join covered by a sling swivel band might be good for some.

I have added length to many barrels over the years, they all get reamed and a liner installed. The Japanese rifle is probably the only smooth bore I have done this way.

[Ballistics in Scotland]

Yes, a liner after adding the extra length would solve that problem in a rifle. Another way I always fancied for a shotgun conversion would be a flush but unwelded joint which could be covered with a wide sling swivel band.

[Ballistics in Scotland]

I've just come across, but haven't yet used, a tool called a rotabroach. It is meant for drills which adhere magnetically to girders etc., and can afford much less pressure than a large diameter drill would require. It is a sort of tubular end mill, with anything from four teeth upwards. I haven't been able to find a specification for the hole down the middle, but it looks like it might be suitable for fitting a rod and pilot to drill a bore to a close tolerance.

[rbertalotto]

I'm just a "garage gunsmith"...But I'll tackle just about anything. My favorite saying is "If a man can do it, I can do it!". If you look around on my website I detail how I've relined a few rifles with excellent results. Lots of pictures and there might be a video.
It really is not that difficult if you understand basic machining and know how to chamber and set headspace. Have at it!

www.rvbprecision.com

[marlinman93]

One of the biggest hurdles for an amateur gunsmith relining a barrel is the cost of getting set up. Often purchasing everything to do it correctly will end up costing much more than having an expert do the task. Unless a individual plans on doing more than one reline in the exact same caliber, it's not something I'd do myself. Not that a hobbyist can't end up doing a great job if he's careful. It just wont save him any money on a one time deal.

[bob208]

i used core drills. core drills are four flute drills that are made to enlarde exsisting holes. they can not walk off.

[Red River Rick]

................ they can not walk off.

Yes they can! Core drills are used for enlarging holes in castings...........and they do run out. You need a piloted drill if you don't want runout.

RRR

[Ballistics in Scotland]

When I work up the courage to reline my .32-40 Winchester, a 5/16in. steel rod is a close enough fit in the bore to act as a pilot. I put more trust in pulling than pushing, for superior chip clearance, and I would like to keep it concentric enough to stop where the join will be covered by the case neck. In the UK a .32-40 is an antique, totally uncontrolled if made up to 1939, provided that it is still in the original chambering. They can hardly quibble that if it is the original chamber.

[Ballistics in Scotland]

Yes they can! Core drills are used for enlarging holes in castings...........and they do run out. You need a piloted drill if you don't want runout.

RRR

I'd agree with this. First, it is important to distinguish them from the great majority of what you will find by searching for "core drill". Those are just holesaws. The core drill intended here might be marginally better than the ordinary twist drill, because three or four flutes requiring leaving more metal in the drill. They are stiffer, and just a little less likely to wander than an ordinary twist drill. But just a little isn't good enough here. I think some kind of pilot is essential for anything but once in a while getting lucky.

[bob208]

a core drill in a casting yes it can but in a hole that is already stright very unlikely. the old armery bit of old had no piolt and they make stright holes.

[John Taylor]

These are probably the best way to go http://pacifictoolandgauge.com/33-piloted-core-drills-nopix- Picture shows a left hand twist but mine is right hand.

[Ballistics in Scotland]

These are probably the best way to go http://pacifictoolandgauge.com/33-piloted-core-drills-nopix- Picture shows a left hand twist but mine is right hand.

Yes, those are undoubtedly the counsel of perfection for this job, and inspire envy in the heart of anyone who does it too occasionally to justify the cost. Can they be fitted to a small enough extension to let the chips clear without frequent removal?

I think an armory drill is what is more often called a gun drill nowadays. But those are designed to drill straight in a solid bar, which is a very different proposition. They have a single edge, coming past the centre, so that the bottom of the hole is like a letter W. Performance in enlarging an existing bore is likely to be unsatisfactory. They also have a straight tubular shank to pass a pumped lubricant, like a circle with a 90 degree segment removed. They would jam up very quickly with chips, so they need a lubricant pressure of around 160psi, several times that of an ordinary lathe coolant setup.

[John Taylor]

All the piloted drills I have used one barrel require frequent removal to get rid of the chips. Sometime they need to be pulled every half inch when removing a lot of metal. The only way to go all the way through would be to use a high pressure pump to keep the chips flushed. When I ream a barrel I have around 1,000 psi oil pressure.

[Ballistics in Scotland]

That is about what I would expect about the drilling. For anybody considering this kind of work I would recommend "Deep Hole Drilling" in the Lindsay "how to" series. It is just a 46 page booklet, a reprint of an edition updated in pre-carbide 1910, but $4.94 on eBay is enough to give a good idea of whether this kind of work is worth doing. I'm some way from my copy at the moment, but I think that is where I got the figure of 160psi for gun drill drilling. Someday I will get around to trying out a gun drill and cheap Chinese 12v pump for that pressure which I have. But it won't be on anything I can't afford to scrap.

I was extremely surprised that you use 1000psi for reaming, although I am sure you are right that it is worth doing. An important point for the amateur is that 160psi with home-fitted connections can be a bit dangerous, and 1000 much more so, for a burst or a squirt can do serious damage. I'd leave the latter to the professionals.

[John Taylor]

That is about what I would expect about the drilling. For anybody considering this kind of work I would recommend "Deep Hole Drilling" in the Lindsay "how to" series. It is just a 46 page booklet, a reprint of an edition updated in pre-carbide 1910, but $4.94 on eBay is enough to give a good idea of whether this kind of work is worth doing. I'm some way from my copy at the moment, but I think that is where I got the figure of 160psi for gun drill drilling. Someday I will get around to trying out a gun drill and cheap Chinese 12v pump for that pressure which I have. But it won't be on anything I can't afford to scrap.

I was extremely surprised that you use 1000psi for reaming, although I am sure you are right that it is worth doing. An important point for the amateur is that 160psi with home-fitted connections can be a bit dangerous, and 1000 much more so, for a burst or a squirt can do serious damage. I'd leave the latter to the professionals.

That's 1000 at the pump and does not have much flow. I usually shut it off just before it clears the barrel but there are signs on the wall and ceiling that I don't always achieve my goal.