barrel relining service?

[G.T.]

Does anyone know any one that is relining Luger barrels?... I have on that I'd prefer to have a pro do?... ... otherwise, I need to learn a whole new skill... we'll see, clocks ticking! Best to all, til...lat'r....GT...

[DavidJayUden]

The only sources I've ever known of where the Broom Closet, now closed, and
redmansrifling.com which may or may not still do relining work.
Not much help, I know. Sorry. You may be due for a new adventure...
dju

[G.T.]

Hi to all! In my initial research, I see it is possible, but maybe not practical? Well, I have too much work in this barrel to quit now. And after searching the available sources, it is too expensive to farm out... Cheapest site I visited listed somewhere in the vicinity of $400.00 to do it? That's the bad part... Now for the good! It would seem that some brave souls have sleeved 9MM barrels down to .30 Luger, mostly in the form of a Beretta 92, and have had excellent results, also, Walther has sleeved their P1's for decades and if it is a problem for them, I've not been made aware? The P1 barrels are press fit without adhesive, I'm going to go slip fit, .0015" to .0020" over the liner dia.? With a high strength gap filling Loctite adhesive. I think it will work out fine? We're going to see, as I'm going to order some Green Mountain .308 1/10" raw barrel blanks early next week.. The steal is 41v50 which I'm guessing is a step up from 4140 which has been used for a lot of factory AR barrels in the past... Wish me luck! My accountant has assured me that again, I can't possible recover my cost or make a profit on the project, so I replied, perfect! And we go forward, again... best to all, til...lat'r....GT..

BTW, I can get 1/11.5" twist, or 1/7" twist? Which would be the best? Anybody have any experience with any of the above…???

[hayhugh]

On ships I have worked on they heat the shaft bearing so that it expands then press force the shaft into the bearing. When the bearing cools they are as one!

[sheepherder]

Originally Posted by G.T.

Walther has sleeved their P1's for decades and if it is a problem for them, I've not been made aware? The P1 barrels are press fit without adhesive...

The P1 barrels had a big problem; the straight barrel liner (no step) would gradually slip forward causing excessive headspace. Walther resorted to a pin in the chamber area to hold the liners in place, but the pin was not positioned correctly initially and the liner would still move forward. They eventually got the pin repositioned and it was considered 'fixed'.

Mark Castel has explained this in John D's sister P38 Forum, along with pictures, IIRC. Mark (who is also a member here) also was kind enough to explain it to me and sent me pictures as well as examples of the liner 'creep'. I think I also showed examples [pics] in my thread over there explaining how I relined P1/P38 9mm barrels to 7.65mm Parabellum.

Might be worth a look.

[DonVoigt]

Rich,
how about a link to your relining thread, please?

[calibrator]

.0015-.002" is a LOT of clearance. You need the liner and barrel to have at least a slight press fit for heat transfer and stability. I'd forego the Loctite. Even the high temp version will liquify with enough heat. The liner creeping over time could be an issue. A step at the muzzle end would be ideal depending on how it's formed.

I'd shoot for a .0005" (maybe even slightly less) press fit. Heat the barrel and cool the liner with nitrogen or dry ice. Get a decent chamfer on the leading edges of both mating parts.

I'd be choosing the 1:7 twist.

I recall when the C96 Forum used to on-line, and seeing some pics of barrels re-lined by the Broom Closet. The liners were definitely off-center when viewed from the muzzle. Many complaints about wildly off-axis round impacts as I recall.

Go with the sheepherder, he's got the knowledge from actual experience. I'm trying to relate my experience with making valve guides for racing engines.

Good Luck ! Your mileage may vary !

[DonVoigt]

I agree that 1-2 thousandths is a lot of clearance, but see no reason not to use loctite.
It's not as though someone is going to overheat a luger barrel in a 1900 by rapid fire, JMHO.

I don't see how a step at the muzzle would help, as I believe the liners creep toward the muzzle; the step needs to be at the chamber end. The liner will have to have a big step there due to the chamber diameter.

For sure getting the barrel drilled/reamed concentrically is the key- unless one just wants it to look like a new bore.

[sheepherder]

Originally Posted by DonVoigt

Rich,
how about a link to your relining thread, please?

http://p38forum.com/forums/showthread.php?t=25831

The Walther is quite different from a Luger. Barrel/breech steel is much harder; I burned out many drills and even a reamer before I realized this. I finally bought a set of Cobalt drills/reamer. I don't know if it is better quality steel or heat treatment. The P1 barrel is also larger in diameter than the P38, making lining it easier. I stepped my liners and barrels to prevent the 'creep'.

Edit: The step was at the chamber end. I have one liner un-installed if anyone is interested in a pic.

Not trying to pooh-pooh Luger re-lining, just expanding on the problems with straight liners. If anyone is really interested in the Walther liner problems, I think Mark had other comments in his threads.

[G.T.]

Great input Joe and Rich! I've been working with Don on this and it looks like we are going forward with the attempt anyway... Here is how I see your concerns, and how we plan to overcome the possible issues noted?
First, our liners will be .500" dia. at the chamber, and progressively reduced or stepped down as we get toward the muzzle.
Second, although .0015" sounds like a lot of clearance, and it might be over the thickness of a washer, but over approximately 5" it is pretty tight? Also, a glue starved bond is possible with an overtight fit?
Third, the shrink fit would be great, especially for a production set up and perfect & clean, 100% concentric parts, our repairs will not quite reach this level of sophistication? Plus, the shrink fit is a one shot deal... No second chance.
fourth, I think the concentricity appearance can be achieved by drilling or reaming from both ends, muzzle end first, chamber end until break thru, then reamers from there on out?.
Fifth, Loctite will be easy to work with, and also permanent! And still resist heat well past high 300 F.
Please note, one thru five are starting points, we are thankful for the suggestions and direction replies from our machinist brothers! Our full circle journey may end us up, right back to the members suggestions noted above... More soon, best to all, til….lat'r....GT

[G.T.]

Hi Rich and Joe, almost forgot! The P1 liner creep is very interesting, I never ever considered using a straight liner, but it is good to know what didn't work out for them on a pretty large effort? Thanks for all, best to you both, til...lat'r...GT

[sheepherder]

You might want to consider silver soldering. The entire liner does not need to be soldered, just one end. For a short distance. Don't use anything from Brownell's; get the real thing from your local welding supply. True silver solder is expensive but also low temp and uses special flux. The metal never even darkens.

I've used stippling, threading, and heat shrinking/freezing on the P1 barrel liners. Pinning turned out the most feasible.

I never bothered with trying to re-line Luger barrels. Why bother when you can buy brand new barrels completely machined??? Collectors don't want re-lined Lugers. There's just no profit in it.

[Mister Sunshine]

A friend of mine wanted to make a target pistol out of a replica of the Remington 1858 cap & ball revolver. He found that the little cadet 310 Martini had the right size bore and twist and were plentiful in gun shops because so many had been converted to 357s and a #001 buckshot worked perfectly. He drilled out the barrel on the pistol and turned down the Martini barrel to match put Lock-Tite on it and pressed it in the revolver barrel, let it set over nite and he found he couldn't turn it with a pipe wrench. He had left a short piece of the insert for the test. Ho could get two pistol barrels out of one 310 barrel. He made up several and none ever shot loose. He was a great pistol shot and difficult to beat . I never did.

[calibrator]

Hey Friend,

When you speak of a clearance of .0015", than is the clearance I hone an exhaust valve guide to in relation to the valve stem dia.

There is a perceptible wobble of the valve when inserted into the guide. I don't think that is what you want. Using anything other than oil when pressing in a valve guide is frowned upon by "Experts" because it will hinder heat transfer from the guide into the head for dissipation.

If you use Loctite on a press fit, you better be pressing it together fast, because even a pause of a few seconds can allow the anaerobic to start and it will seize up.

Drill bits wander, even drilling an existing hole, especially over a distance of several inches. Forget about drilling from both ends, meeting in the middle, DOH !

Look at a "Piloted Core Drill Bit";

http://pacifictoolandgauge.com/33-pi...-drills-nopix-

The above is only an example (the 1st image I could access). It will faithfully follow the existing bore if you can get a proper sized pilot tip. There are some that will have a 90 degree cutting edge that would allow you to leave a square shelf as a stop at the muzzle end if you halted .060-.090" shy of breaking through. The ID of the hole left by the core drill determines the OD of your new barrel blank. Drill 1st, then size the barrel blank accordingly.

The Silver Solder is a good idea, because it would not be as notable as a step or a pin.

[DavidJayUden]

Larry Potterfield of Midway USA has a video how-to for relining a common .22 rifle barrel, just in case anyone is curious. https://www.youtube.com/watch?v=XZ7sQya7tyk

dju

[DonVoigt]

GT,
just fyi, the piloted drill mentioned by calibrator is a great idea.
Only downside is $75, and 6-8 wk lead time from Pacific.

I plan to try to make a similar "piloted drill" from a stepped drill, by adding the pilot.

Calibrator wrote:
"There are some that will have a 90 degree cutting edge that would allow you to leave a square shelf as a stop at the muzzle end if you halted .060-.090" shy of breaking through."
Unfortunately the step Must be at the rear, a straight liner will not "fill" the chamber area of the luger barrel, and requires a large step
at the chamber end.

Rich,
for sure this doesn't make any sense economically, but 1900 barrels are not plentiful. GT is trying to save a matching 1900, with a bulged barrel.

We're doing this for "fun", as you have so many of your cool projects!

[sheepherder]

Originally Posted by DonVoigt

Rich,
for sure this doesn't make any sense economically, but 1900 barrels are not plentiful. GT is trying to save a matching 1900, with a bulged barrel.

We're doing this for "fun", as you have so many of your cool projects!

Quash a bulge? Re-line a pencil taper 1900 barrel? Sounds like fun!

[sheepherder]

Originally Posted by G.T.

I've been working with Don on this and it looks like we are going forward with the attempt anyway.

Please take lots of pictures! And a running commentary on your progress!