Damaged Rossi Puma

Hi guys

Ok, I know this isn related with precision rilfes, but I need all the helps available. Tried other gunsmith forum, with no luck

I have one Rossi Puma (Winchester 94 clone) that I messed the threads while trying remove the barrel for crow work.

The threads are damageg, at the receiver and the barrel for 1/2 extension of theads lengths.

The barrel is easy to repair, but my problem is the receiver.

The threads are 25 tpi and outside diameter is .778"

There is any tap this size available anywhere, so I can repair the receiver without losing my friend?

I have some custom BR rifles and just assembled one myself, with goods results, but this kind of rifle is totally new to me.

Excuse any language errors.

The thread is M20X1.0 almost certain.

I agree that it is very likely M20x1.0. You can get a decent quality tap here: HS Metric Plug Taps for hand tapping

RWO

If you just need to "clean out" the threads in the receiver, why not make your own tap?

Just thread a piece of O-1, cut a few slits in the sides, taper the end slightly, and have at it. You could even harden and temper it, but for a one-time use, there is probably no need.

One thing you do want to think about, though, is if the damaged threads will cause any loss of strength in the barrel.receiver joint.

awander said:

If you just need to "clean out" the threads in the receiver, why not make your own tap?

Just thread a piece of O-1, cut a few slits in the sides, taper the end slightly, and have at it. You could even harden and temper it, but for a one-time use, there is probably no need.

One thing you do want to think about, though, is if the damaged threads will cause any loss of strength in the barrel.receiver joint.

Click to expand...

Thanks to all.


Awander, I am a do yourself kind of man. But as a newbie in the gunsmithing, I have a lot to learn.

I have a good lathe and milling machine, that I bought for rifle work for my self.

But dont know nothing about this steel. (0-1) Is know with other names? Where can I find then?

Thanks so much

Hi LME:

O-1 is an Oil-Hardening Drill Rod. In England I think they call it Silver Steel.

Buy the tap from Victor Machine and write it off as a learning experience. Trying to run a unhardened O1 tap into your receiver which more then likely is harder the a piece of O1. You don't want to start another thread asking how to remove a seized piece of steel in your receiver. P.S. You didn't have to remove the barrel to recrown it.

paracongo308 said:

Buy the tap from Victor Machine and write it off as a learning experience. Trying to run a unhardened O1 tap into your receiver which more then likely is harder the a piece of O1. You don't want to start another thread asking how to remove a seized piece of steel in your receiver. P.S. You didn't have to remove the barrel to recrown it.

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Paracongo 308.
My first intention was recrow the barrel using one PTG tool as this

PTG Interchangeable Pilot Muzzle Crown Tool #1 Target

I tested in one Krieger barrel and worked fine. But in the Puma barrel, Ive got a lot of chatter. Seems a lot harder than normal.


If I decide go ahead in making the tap from 0-1 steel, will a ceramic insert work to make the threads, mill out the grooves and then oil hardener it?

LME,
If you are going to make your own tap you might be well off to do a little research about how to harden the grade of tool steel that you get. O-1, A-2 etc.
The trick is getting the temperature correct for your need. Some grades are more forgiving than others. I would personally buy a tap, but the heat treating is a good skill to learn, there just might be a better time that is less important.

What does a ceramic insert have to do with making a tap? it sounds like your somewhat confused on making a tap and there is a lot more then just turning some threads on a piece of tool steel and then milling some flutes for chip clearance. The lead on a tap must be radially backed off in order for it to cut. Take a look at this special non standard 1.900" tap I had to make for a job a few years ago, the lead is radially backed of on each flute. The tap was gas quenched in a vacuum furnace. Without backing off any tap all you will do is get the tap stuck in the material, and if you do not understand this your best bet is to buy the ground tap form a supplier. Some day when you are more skilled and still want to work on firearms you can make your own recrowning tools like I made myself 25 or so years ago.

Well, I still maintain that he doesn't really need a tap-just something to clean up the existing threads that were damaged.

Lme , when using those crowning tools and you get chatter, try packing the flutes with a heavy grease or wax and spinning it with a hand drill.

paracongo308 said:

View attachment 141658View attachment 141659What does a ceramic insert have to do with making a tap? it sounds like your somewhat confused on making a tap and there is a lot more then just turning some threads on a piece of tool steel and then milling some flutes for chip clearance. The lead on a tap must be radially backed off in order for it to cut. Take a look at this special non standard 1.900" tap I had to make for a job a few years ago, the lead is radially backed of on each flute. The tap was gas quenched in a vacuum furnace. Without backing off any tap all you will do is get the tap stuck in the material, and if you do not understand this your best bet is to buy the ground tap form a supplier. Some day when you are more skilled and still want to work on firearms you can make your own recrowning tools like I made myself 25 or so years ago.

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Hi Paracongo308.

I would like to understand the process od making the tap, even if I decide to buy one.

What kind of tool must be used in the lathe to make the threads, as the tool steel is very hard?

Do I need heaten it and cool slowly before working in the lathe?

Thanks to all who replied

LME said:

Hi Paracongo308.

I would like to understand the process od making the tap, even if I decide to buy one.

What kind of tool must be used in the lathe to make the threads, as the tool steel is very hard?

Do I need heaten it and cool slowly before working in the lathe?

Thanks to all who replied

Click to expand...

O series tool steels are supplied soft enough to work with normal machine tools.
Once the part is formed, they are heat treated.

Turning a thread on a lathe is simple enough, cutting flutes with a mill is not bad either.
The big trick is proper relief of the tap behind the cutting area.

You can go on line and fine a lot U tube videos showing various tricks for home shop heat treating.
The part has to be heated hot enough that it loses its magnetism and then a bit more.
It needs to uniformly heated and cooled quickly.
O series steels will cool quickly enough in oil, W series - water, A series - harden in air.
Once hardened, the part must be tempered - heated to a known temperature for a known time to achieve a desired hardness.
Some try to judge this by oxidation colors that form on a polished surface.
That's the old school way of doing it with simple carbon steels.

Lots of U tube home shop advice that works in this area.
For a 1 off special you cant get another way and wont use a lot its fine.
If your betting your life on it, that's something different.


If you can buy the tap your way ahead.
It will be sharper, closer to nominal form and properly heat treated.

You can also try running a well lubricated Allen head bolt through the hole.
They are usually grade 12 or better. The objective is to restore the thread form, not remove more material.
If the threads are a little dinged up forcing them back to form may be a better choice.
If threads were stripped or ripped out because the barrel galled to the receiver, it may not have enough material left to retain the barrel.