Spot annealing

[epc308]

I need some info on spot annealing a Rock Island ‘03 Springfield receiver so I can drill and tap it for Lyman/Unertl style scope blocks, and/or, a scope mount. I don’t know if that particular one is case hardened or through hardened, or if that makes any difference on how to do it.
Thanks in advance.

 

[Papa Charlie]

I have used a Cobalt drill bit to drill through case hardened steel before. They are expensive and very brittle so good idea to watch a couple of YouTube videos before if you haven't used them.

 

[kendog]

Drilling them is no problem. Straight flute 2 groove carbide drill bit will punch cleanly through them all. Tapping is another story. Usually the hardness on the back side of the hole will get you. I use a Smith mini torch. Drill hole, polish a small area around hole to bright metal, heat hole till it turns blue, then polish the blue away with some sand cloth, or craytex. Heat, polish, rinse, repeat in a small area and stop when the blue creeps back on its own into the area you just polished. Then let it cool slowly. This usually gets the back side of the hole with no damage to the lug seats. Run tap backed up with a guide in the mill spindle. No achy breaky that way. Usually it is the ring that presents the biggest problem, once in a while I have come across a hard bridge also. Whatever you do, do not let it get quenched while you are doing this, as it will get harder than rat's teeth and no amount of annealing will undo it.

 

[Fast14riot]

Is it a low number receiver?

 

[epc308]

Is it a low number receiver?

Thanks for the responses. Fast14riot- Define low number. This Rock Island is 16xxx. Do all the 03 receivers use the same numbering system, or did each manufacturer have their own?

 

[epc308]

I have used a Cobalt drill bit to drill through case hardened steel before. They are expensive and very brittle so good idea to watch a couple of YouTube videos before if you haven't used them.

Cobalt or carbide?

 

[carlsbad]

carbide. Not cobalt in this application. However, carbide drills are very brittle. Carbide end mills can be a better choice. You almost have to do it in a milling machine with high RPMs and low runout on the spindle. As stated, straight flute is the way to go.

SOWA redline taps are rated up to 48HRC which is probably good enough--but not always. Some of these actions are harder than that.

 

[nicholst55]

Thanks for the responses. Fast14riot- Define low number. This Rock Island is 16xxx. Do all the 03 receivers use the same numbering system, or did each manufacturer have their own?

Springfield Armory, Rock Island Arsenal, and Remington were all assigned separate serial number blocks to use when producing rifles. Rock Island receivers below SN: 286,506 are considered 'low numbers,' and received a single heat treat. There is a concern that many were over heated during heat treat and are subject to be brittle, potentially resulting in catastrophic failure. There is much heated discussion about this subject, and you can research it on the Internet. The Army withdrew low numbered rifles from service. The USMC continued their use throughout WWII. Personally, I would err on the side of caution and not use your receiver.

 

[Papa Charlie]

Cobalt or carbide?

Sorry mixed up my metals, Carbide. That's what happens when you get older.

 

[epc308]

Springfield Armory, Rock Island Arsenal, and Remington were all assigned separate serial number blocks to use when producing rifles. Rock Island receivers below SN: 286,506 are considered 'low numbers,' and received a single heat treat. There is a concern that many were over heated during heat treat and are subject to be brittle, potentially resulting in catastrophic failure. There is much heated discussion about this subject, and you can research it on the Internet. The Army withdrew low numbered rifles from service. The USMC continued their use throughout WWII. Personally, I would err on the side of caution and not use your receiver.

nicholst55- this was a parts gun made up to be a .22RF sometime in the past, which I think will be safe in that application. A friend bought it at the Tulsa show some years ago after trying his level best to talk me into it. I put a liner in the barrel for him, turned off the lump for the front sight, polished and blued said barrel. It came with a Canjar trigger that feels pretty darn good. He's currently fitting up a stock for it.

 

[epc308]

Sorry mixed up my metals, Carbide. That's what happens when you get older.

Papa Charlie- I totally understand the getting older part. I will set this up in my milling machine to drill and tap, so things won't move around. Drilling doesn't concern me nearly as much as the tapping. A
#6-48 isn't the strongest thing. I've watched them twist a bit in metal that wasn't as tough as this RI has the potential to be.

 

[epc308]

carbide. Not cobalt in this application. However, carbide drills are very brittle. Carbide end mills can be a better choice. You almost have to do it in a milling machine with high RPMs and low runout on the spindle. As stated, straight flute is the way to go.

SOWA redline taps are rated up to 48HRC which is probably good enough--but not always. Some of these actions are harder than that.

Carlsbad- I will set it up in my mill and lock things down so things won't move around.
I haven't heard of SOWA taps before. I'll do a search for them. Thanks for that info.

 

[Fast14riot]

nicholst55- this was a parts gun made up to be a .22RF sometime in the past, which I think will be safe in that application. A friend bought it at the Tulsa show some years ago after trying his level best to talk me into it. I put a liner in the barrel for him, turned off the lump for the front sight, polished and blued said barrel. It came with a Canjar trigger that feels pretty darn good. He's currently fitting up a stock for it.

It'll be fine as a rimfire.

 

[epc308]

Drilling them is no problem. Straight flute 2 groove carbide drill bit will punch cleanly through them all. Tapping is another story. Usually the hardness on the back side of the hole will get you. I use a Smith mini torch. Drill hole, polish a small area around hole to bright metal, heat hole till it turns blue, then polish the blue away with some sand cloth, or craytex. Heat, polish, rinse, repeat in a small area and stop when the blue creeps back on its own into the area you just polished. Then let it cool slowly. This usually gets the back side of the hole with no damage to the lug seats. Run tap backed up with a guide in the mill spindle. No achy breaky that way. Usually it is the ring that presents the biggest problem, once in a while I have come across a hard bridge also. Whatever you do, do not let it get quenched while you are doing this, as it will get harder than rat's teeth and no amount of annealing will undo it.

Don dropped off the RI Springfield over the other day. The mount he brought is a brand new, never used, old school Maynard P. Buehler Micro Dial Universal. In the original instructions(!) it has info for annealing. They say to take a 3/4" square block, heat to cherry red, set it on the receiver and leave it till cool. Ever hear of this method?

 

[kendog]

Don dropped off the RI Springfield over the other day. The mount he brought is a brand new, never used, old school Maynard P. Buehler Micro Dial Universal. In the original instructions(!) it has info for annealing. They say to take a 3/4" square block, heat to cherry red, set it on the receiver and leave it till cool. Ever hear of this method?

Not that one exactly. I got my method from one of the Brownells Kinks books. Several in there, soldering coppers, aluminum pins, torches, etc. This one works best for me in my shop with available tools and works on all sorts of glass hard receivers, even US 1917's. I like my method because it keeps the annealed zone to an absolute minimum, and is relatively quick to accomplish while the parts are in the mill so I can drill, anneal, and tap without breaking down the setup.

 

[epc308]

Not that one exactly. I got my method from one of the Brownells Kinks books. Several in there, soldering coppers, aluminum pins, torches, etc. This one works best for me in my shop with available tools and works on all sorts of glass hard receivers, even US 1917's. I like my method because it keeps the annealed zone to an absolute minimum, and is relatively quick to accomplish while the parts are in the mill so I can drill, anneal, and tap without breaking down the setup.

Do you do your annealing with the barrel still in place? It would seem like a huge heat sink to me. I know this one will come out easily as I had it out last year to install a liner.

 

[akajun]

If you have an arc welder and can get ahold of some carbon gouging rods that is the slickest way to spot anneal I’ve found.
Simply touch the end of the rod to the spot you want to anneal , have someone turn on the welder, and let that spot heat up then turn off.
If you don’t want to go that route as stated before a carbide spotting drill to crack the skin then a regular drill to finish the hole.
You can get rid of the case on the backside of the hole with a dremel and a carbide ball burr by sticking it in the hole and working the underside though.
Even though expect to chip a few teeth off the taps.

 

[shortgrass]

I guess the method I've used is too simple. Get through that hard 'skin' with a carbide drill, continue to the target depth with a new, HS drill bit. Then, anneal the edges of the hole with a 0000 oxy/act torch. The edges of the hole heat up quickly, giving the heat very little time to travel, before dissipating,,, not effecting critical areas.

 

[Ggmac]

Don dropped off the RI Springfield over the other day. The mount he brought is a brand new, never used, old school Maynard P. Buehler Micro Dial Universal. In the original instructions(!) it has info for annealing. They say to take a 3/4" square block, heat to cherry red, set it on the receiver and leave it till cool. Ever hear of this method?

That was an acceptable way long ago . If your handy , sounds like you are the best way to spot anneal is written up in Dunlaps book , I think , anyway here goes ; get a 1/4 ( aprx ) carbon rod , wrap in heavy 10 gauge copper wire , fix a wooden handle to one end , attach the ends of the copper to a good 6-12 volt DC battery . I've got new carbon rods , but shipping is a problem for me currently. I've used the innards of an old oven element , but I would be careful as 12 volts was too much .
I'll try to find the book and I got the carbon arc rods from Amazon .
Of course the battery will turn the carbon rod very very hot ( remember the wood handle ) and you place this on the spot to be annealed till it gets red but not radiating out mor than say 3/16-1/4"
I use to use a Mac tool they had for marking you tools with a 12 volt battery . It's basically the same as what I described but has a spring in it that vibrates on and off to keep from annealing the piece your trying to mark
Gary

 

[hpshooter]

"I'll try to find the book and I got the carbon arc rods from Amazon "

A for real welding supply store will stock copper coated carbon electrodes used for arc gouging. May have to buy a box of them. We used 1/4 inch ones when I taught at the local trade school. I think we got them in 12 count boxes.

Edited: old style "D" cell batteries have a carbon element in the center. That and a 12 volt car or lawn tractor battery should do the job for little cash out of the pocket.