Rebarreling a 1903A3...

[tobnpr]

Customer has a couple of 98 Mausers and a 1903A3 he's bringing in for rebarreling.

I'm told the 03 is a DP marked receiver. Assuming inspection shows just minor tack welds at the receiver ring any reason to suspect damage to the heat treat? Haven't worked on one of these yet so looking for input from those who have. If I see any evidence of more destructive welding I'll punt it back to him.

I believe he's bringing a take-off for the rebarreling. Assuming the "usual" work of setting back the shoulder, breech, and deepening the chamber- how is the extractor cut handled, is there a standard width key cutter that will make short work of this in the mill?
Also wants D&T for a mount- I've read the receiver can be as hard as peckerwood, is it necessary to spot anneal for this?
Anything else to know about the 03?

 

[akajun]

The Drill purpose receiver with a small tackweld is not an issue. Ive built quite a few and fired them a lot. , all accurate in fact I took 2nd at perry one year in the springfield match with one. Examine the weld, use your best judgement and proceed. Just lightly clean up the receiver face as the weld spot will distort it in that spot a few thou. The extractor slot if he's using a take off or a new criterion barrel is also a non issue. The receiver threads are timed, If it overtimes upon installing it you'll have to make or find some breaching shims or peen the barrel shoulder.
The Drill and tap, yep they can be rock hard. Spot anealling with a carbon arc rod and an arc welder works. You can also use a carbide drill to crack the skin ( on both sides) and a regular drill to finish the hole, a carbide burr to do the same but it wont be through holes. Either way youll need to chamfer both sides of the hole with a small abrasive bit in a dremel to tap it if you dont anneal the hole or youll break off teeth on the tap when it hits the hard skin. Use one of the thick (honey like) fluids to tap.

 

[Ggmac]

do you know how to make a carbon arc rod to anneal? I think Brownells 1st gunsmith kinks has the info

 

[Ggmac]

ive got a dozen or so extra rods , just pay for the ride

 

[tobnpr]

^^
Nope, haven't done it before.
I've read about chucking a small dia steel rod (even a nail ground flat), heating it red hot and running it against the area to be drilled, or if the hole is able to be drilled with a carbide end mill (perhaps?), using the same idea- sinking a red hot steel rod the diameter of the mill/drill bit into the hole and allowing the heat to transfer.

No arc welder. Just a MIG.

 

[jackieschmidt]

The thing about DP Rifles is you never know why the Armorer designated them DP. Many were simply a bunch of miss matched parts rendered non fireable with creative things like driving a nail in the firing pin hole or putting a bead of weld in the chamber.

Here is a link to the Hatcher Reports on military actions and barrels. I have a pretty good knowledge of steel alloy composition and heat treating procedures, and even some of this can make my eyes glaze over.

Hatcher's Notebook

Handgun enthusiasts, gun-owning do-it-yourself, law enforcement officials, and gunsmiths here is the ultimate one-volume guide to acquiring and developing all the necessary skills for making pistol repairs at home, from helpful hints on work space and setting up a small shop, to the tools needed...

books.google.com

It also shows that through the decades of production, different ordinances used different steel alloy and different methods of acquiring the best combination f strength and hardness. Some were carburized, some received the hardness from the actual temper quench. It all depended on what steel was used.

as to your questions, the extractor cut out can be cut with a 7/16 woodruff cutter, or a smaller cutter done insteps. The key is to get it clocked correctly.

I have only done a barrel job on one 1917. The biggest problem was getting the original military barrel off. It is a square thread, and many were put on really tight.

the way I clocked the extractor slot was I torqued the barrel on the action and put a small witness mark. I then took a 7/16 square piece of high speed steel, slid it into the receiver slot against the barrel,and gave it a tap to mark the barrel..

I then unscrewed the barrel, set it up true and square in my mill, and cut the slot to the required depth, which turns out to be jus at the edge of the chamber.

I then installed the barrel to the witness mark.

 

[epc308]

The thing about DP Rifles is you never know why the Armorer designated them DP. Many were simply a bunch of miss matched parts rendered non fireable with creative things like driving a nail in the firing pin hole or putting a bead of weld in the chamber.

Here is a link to the Hatcher Reports on military actions and barrels. I have a pretty good knowledge of steel alloy composition and heat treating procedures, and even some of this can make my eyes glaze over.

Hatcher's Notebook

Handgun enthusiasts, gun-owning do-it-yourself, law enforcement officials, and gunsmiths here is the ultimate one-volume guide to acquiring and developing all the necessary skills for making pistol repairs at home, from helpful hints on work space and setting up a small shop, to the tools needed...

books.google.com

It also shows that through the decades of production, different ordinances used different steel alloy and different methods of acquiring the best combination f strength and hardness. Some were carburized, some received the hardness from the actual temper quench. It all depended on what steel was used.

as to your questions, the extractor cut out can be cut with a 7/16 woodruff cutter, or a smaller cutter done insteps. The key is to get it clocked correctly.

I have only done a barrel job on one 1917. The biggest problem was getting the original military barrel off. It is a square thread, and many were put on really tight.

the way I clocked the extractor slot was I torqued the barrel on the action and put a small witness mark. I then took a 7/16 square piece of high speed steel, slid it into the receiver slot against the barrel,and gave it a tap to mark the barrel..

I then unscrewed the barrel, set it up true and square in my mill, and cut the slot to the required depth, which turns out to be jus at the edge of the chamber.

I then installed the barrel to the witness mark.

Thanks for the extractor insight. I have a M17 to fit with a barrel, and this should be helpful. Thankfully, the old barrel is already off, and will be fine for copying.

 

[Ggmac]

If you have a problem getting the barrel off and your not saving the DP barrel anyway, just cur a relief a few thou in front of the receiver . Be careful with the weld , go slow , it may require a cut off wheel on an angle grinder . Yup , its that hard .

 

[spitfire_er]

Here's what my extractor cut setup ends up being. This was an old cutter that I made from a horizontal mill cutter that had a little excess chatter, but did the job. I now have a better cutter setup. A decent size woodruff cutter will do the same thing. This is a 1917 barrel. Mark them similar to how Jackie explained. I have a 6-7" long HSS blank that is ground on one end to a sharp edge along one corner. Hold tight to the bottom or top rail, tap the back of the barrel and it marks your top and bottom. The cutter I have, you make one cut and it's done, About 4-5 mins to cut.

If you want to get dead nuts for the index, level it out in the V-block and remove your barrel while the V-block is still attached. May need to hold further down on the barrel, but works great. Otherwise you could technically put a very light mark on the L rail side and index with a precision level/square or which ever method you prefer.

 

[tobnpr]

The receiver threads are timed, If it overtimes upon installing it you'll have to make or find some breaching shims or peen the barrel shoulder.

Why wouldn't I machine the breech/shoulder and adjust chamber depth like I normally would?
Shims or peening a gap between the barrel shoulder and receiver ring just doesn't seem "right" to me.

 

[akajun]

It’s a military rifle and the military surplus barrels and new criterion barrels already have tye extractor cut and the keyway for the front sight cut the reciever threads are timed so all barrels will reasonably time up
However 1900-1945 wartime tolerances mean some will be perfect, some will be over, some under
Under is easy, shave the shoulder in your lathe , over requires shims or peening as 10 tpi square threads don’t lend themselves to going to the next thread . This has been standard procedure for these guns and they will shoot very well. You’ll still have to check the headspace after installation and maybe cut it with a pull through reamer. If your using a military barrel, it may be “ excessive” but if it doesn’t close on a field gauge it’s fine.
If it’s in military configuration you’ll do better concentrating on stick fit and 7.5lbs of forend pressure. Also make sure both bolt lugs engage fully, most don’t unless they’ve been lapped in.
But if your going with an unchambered blank
Do whatever you like

 

[tobnpr]

^^^
Thanks. Haven't laid eyes on it but he says it's a take-off.
Interesting that receiver and barrel threads were timed way "back in the day".
I'm looking at the tenon print from the old Trinidad book.
Shows .734 length, 41 degree cone.
Haven't worked on a coned breech yet....
If I need to face the shoulder (under-clocked), I'd presumably need to face the breech by the same amount, re-cut the cone, deepen the chamber- correct?

 

[akajun]

^^^
Thanks. Haven't laid eyes on it but he says it's a take-off.
Interesting that receiver and barrel threads were timed way "back in the day".
I'm looking at the tenon print from the old Trinidad book.
Shows .734 length, 41 degree cone.
Haven't worked on a coned breech yet....
If I need to face the shoulder (under-clocked), I'd presumably need to face the breech by the same amount, re-cut the cone, deepen the chamber- correct?

No i never have, your facing the shoulder just to make it time up right
You want it to stop about 1130-45 then draw up to 12 o’clock with some muscle.
The o3 like most battle rifles leaves lots of clearance so the breach clearance is generous
You can check it with plasti gauge if you want

 

[Ggmac]

Use the best lube you have . Ive used white lead , STP , copper never seize , moly and more . STP was better than expected .

 

[55fairlane]

I have never refurbished a drill rifle (that I will tell about) but, o.e. barrels or reproduction barrels (I got a couple from the CMP store) unscrew the old barrel (creative use of lathe may be needed) lube the threads, screw the barrel on until the timing marks line up, you should be good to go

 

[tobnpr]

^^^
Thanks, guys- much appreciated.

 

[spitfire_er]

If the extractor doesn't line up, cut a new extractor slot where it does. Shouldn't be that far off. Peening and shimming isn't correct. I would be royally p'd off if a "Gunsmith" did that to my action and we would have issues. You could technically have an extractor cut from about 1:00 to 5:00 and it won't impead function. If it ends up at 12:00. Ide set it back. At what point labor gets to be to much is up to you and the customer. Most people don't realize that trying to save a buck with an old barrel can cost more than it's worth in labor in a case like this. Sometimes they get lucky though.

I tell people can be anywhere from $100 if it takes minimal work on up to new barrel fitting price with extensive machining. I do the same quality work on every barrel though, full custom or military action. When done right, these old military actions can shoot!

 

[Ggmac]

If the extractor groove doesnt line up then the front sight key slot will not line up also . On a 1903 it was taught and common to peen barrel WHEN shims were not available. Easy enought to make shims which is the preferred way .
On any other barrel install with out front sight key slot cut already, I would recut slot . Ive done many dozen 1903 and A3 , and Enfields , not all lined up .
It was easy when you had a case of barrels to try ( 1903 A3)

 

[hpshooter]

" Ive used white lead "

Sure miss that for dead center lubricant! Thanks EPA for protecting me from myself (said with tongue in cheek).

 

[spitfire_er]

My mind wasn't thinking military barrel. Then yeah you have to deal with the sight groove.