D&T P14 reciever.

[frnkeore]

I had this posted in the Military guns section of the forum but, figured that I might get some creative answers here. For pictures of the gun, look under 1914 Enfield over there.

This is regarding drilling the reciever ring for two 8x40 tapped holes. The rear sight had been sawed off.

I milled off the saw marks with a insertable carbide end mill and noticed that the metal was hard but, I know they're made with nickle steel. Then, I started the center drill into the reciever ring and was suprised to hear it squeek and then dull completely. So, I figured it was case hardened and that it would be soft enough under it........... NO WAY, it's hard all the way through. I had to use a 1/8" carbine end mill to make the hole, I couldn't even enlarge it with a HS drill. I did get it to .140 for the 8/40 tap with carbide but, I don't dare try to tap it.

I had no idea that my P14 would be that hard, are all P14's harden like this? I was told by a local gunsmith that the P17's aren't hard like this.

HELP!!!!!

Frank

PS
I did find a carbide tap at MSC (not 8/40 tho) for $100 but, that's what I paid for the rifle.

[HollowPoint]

Hi Frank:
I don't own a P14 but a few yeas back when I was trying to drill and tap the receiver of my K31 I ran into the same problem with the metal being incredibly hard.

I too, asked around about the type of metals used for these receivers. I was generally told that the metal on my K31's receiver was just surface hardened and once I got past the surface my drill bit should cut right through.

This darn receiver must have been made of Cryptonite. I ruined several of my most expensive drill bits and it wouldn't even scratch the surface. (This is no exaggeration)

After all that effort and ruined drill bits I finally got some input from a guy who had been there and done that. He recommended that I buy a "HiRoc" drill bit of the correct diameter and it should cut right through.

That tiny little drill bit cost me $15.00 at the time. I still have it in my shop somewhere. I used it to drill two holes. It cut through my K31's receiver like it was hot butter. This same guy also suggested that I do the following in order to tap this same receiver.

Wether his advice was the best way to go about it is anybodies guess but, since he hadn't steered me wrong about the drill bit, I went ahead and did it exactly how he said. It took a little patience but it worked like gang-buster.

He instructed me to stick one of my ruined drill bits down into the holes I'd just drilled, then get my small butane torch and aim the flame at the drill bit just above the receiver. (do not aim the flame at the receiver.)

Keep the flame on the drill bit and allow it to get glowing-hot. It took a few minutes but eventually the heat from the drill bit worked its way onto the holes I'd drilled causing the inside surfaces of those drilled holes to become annealed.

The remainder of the receiver retained its original hardened-state while the metal in and around the holes themselves became soft enough to tap. I used a high carbon tap to thread my holes just in case I snapped one of them in the holes.

If it's a high carbon tap it's possible to chip them out without causing any damage to the receiver. The alloy taps get a little tricky.

Anyway, that's how I managed to drill and tap the holes I drilled into my K31's receiver. There are more than likely other ways to go about it. This just happens to be the only way I have any hands on experience with.

Hope it helps.

HollowPoint

[skeettx]

In the old days we would take the carbon rod out of a "D" cell battery, sharpen the rod with a pencil sharpener, Using jumper cables and a car battery, Hook the negative to the action and the positive to the carbon rod. Clamp to the area to be drilled, the rod will heat up FAST and unharded the spot to be drilled. When all is set, hook the cables to the battery
As the heat up occurs, you will see a color change at the area.

See "Gunsmith Kinks" Vol 1 page 299

I have also used high speed CARBIDE dental burrs and a Dremel tool

Mike

[nicholst55]

Hi-Roc drill bits can be purchased from Midway or The Drill Bit Warehouse.

Hi-Roc Drill Bits (http://www.midwayusa.com/Find?userSearchQuery=Hi+Roc+Drill+Bit)

Spot-annealing is an old, old gunsmith trick - regardless of how you do it.

[Mk42gunner]

I have never drilled a P14, but I have done a couple of M1917's and they were the toughest actions I have ever drilled and tapped. They were worse than any of the Mausers I ever did.

It has been a few years, but it seems like I bought a solid carbide drill, and it was stil a pain.

Robert

[elk hunter]

P-14 and M-17 Enfields along with some Springfield receivers can be harder than woodpecker lips. I use a solid carbide drill from Brownells on them, and then use a new carbon steel tap for each hole. I don't try to use the the tap on a second hole, I just throw them away so I won't be tempted. If the tap breaks you can drill them out with the carbide drill or use a dental burr to cut them up to remove them. The taps are quite a bit harder than a drill bit and will generally cut the hard steel. Be sure to use a good tapping fluid.

[trench]

yep, tap magic is what you want. Drilling is easier than tapping. Just because you can drill a hardened pc of metal does not mean that you can tap it.

[KCSO]

Here is my trick on these. I use a carbide bit to drill the hole and then I put in an aluminum rod and heat it till it almost melts. This draws the temper from the receiver right around where you need to tap, then tap with a fresh sharp tap. Yea a lot of those olf P14's were HARD!!! I can remember cracking receivers taking out the barrels with a 20 ton barrel press and a 4 foot cheater on the action wrench.

[JIMinPHX]

There are guys out there that do "thread grinding" too. I don't know if you will find a shop that does internals that small, but grinding threads into hardened steel has been around for a long time & produces wonderful results when done properly. It's something that you would need to get done by a specialty shop. The equipment is not cheap. Thread milling with a carbide tool may also be an option. It's a similar operation.

Some of the Jerry K books recommend annealing the entire action, tapping & then heat treating the whole thing again. That seems expensive & risky to me.

Spot annealing, as others have recommended, sounds like the trick to try if you want to do it yourself.

[frnkeore]

I'm a retired machinist and have done thread milling. I'm not sure of the cost of a 40 pitch carbide thread miller but, a $150 setup/programing charge, min $80 shop shop time and the cost of the carbide miller would make it a bit much. BUT, it would sure give me great bragging rights :)

Frank

[nanuk]

I've read the trick of heating the tip of a steel rod that just fits into the hole, and then pound it with a couple good taps to fill it out.

wait till it cools and pull it out, hole should be annealed enough into the surrounding steel to tap.

if rod sticks, drill it out.

I've never tried it though

[frnkeore]

Well, today is the day I'm going to try the heated (red) rod in the hole. I'm going to be using a propane torch so, that maybe the limiting factor.

I'll give the results in a day or two.

Frank

[nanuk]

get the rod good and hot!

let us know the results!

[frnkeore]

Failure so far, I only have a propane torch and couldn't get the 5/16 rod red hot. I have to find a way to heat it to red. May have to build a wood fire.

Frank

[nanuk]

get a washing machine tub, cut a few extra slots and bend them in for extra holes. knock one hole in so you can insert a rod.

get a fire going and fill 'er up with some good dry wood, preferably hardwood

have a fan ready to blow on the barrel, and when she is good and HOT, insert your rod into the coals.

as the air moves through, it will be almost whitehot in there judging by the nekid eye...

when your rod is yellow, it should be hot enough...






maybe.....

[frnkeore]

Thank you, nanuk.

I bought another (higher out put) propane torch yesterday and will try it in the next few days but, if it doesn't do the job, the wood will come out :)

Frank

[Milsurp Junkie]

there is always MAPP and Oxygen torches. Not too expensive and will get it hot enough.

[nanuk]

MAPP/O2 can weld steel can it not?

that SHOULD get it hot enough!

[frnkeore]

Well, I got it :)

I wound up buying a $30 propane set from Harbor Frieght. It has a a few tips with it and the one that worked for me was a kinda wrap around one. It covered about 270 degs so, I could put the 5/16 rod with the .140 dia tip in the middle (holding it with vise grips) and it would turn it bright red in about 30 - 45 seconds. I put it in the hole twice after heating then realized that I could keep the heat on the rod with the new tip and not have the torch very close to the receiver ring (the rod was about 3.5 long). Any way, I got the new metal in the drilled hole completely black, indicating to me that it was around 900 deg and it was soft enough to tap.

Job done!!!!

Thank you all for the advise,

Frank

[nanuk]

good to know that rod thing works well!

I just picked up a P14 with the ears milled off, and was thinking receiver sight.....

[Brithunter]

Sorry should have thought of this the other day :roll:

At what speed did you run that carbide cutter?

what diameter is the cutter?


At one place I had to mill donw a chunk of tool steel for a bit. The billet was at least 5/8" too thick. I started as per "usual" with a 8" Dia carbide insert cutter at about 1000RPM taking 0.80" dee cuts and the cutter tip burnt.. One of the regular guys can over and advised I slow the cutter down to 350 RPM with 10" per minute feed and take 1/4" deep cuts. I was ceptical but tried it and it cut like butter. Keeping the tips loaded they didn't heat up and burn but transferred the heat to the chips. The finish was superb.

Later this came in handy at another place where an apprentice was given a carbide top lathe holder to mill down to fit a smaller machine. he also had the tips burning so i passed on the advice and low and behold it worked on that tough steel too.

We get so tied into carbide needs speed....................................... when it fact carbide needs to be loaded and the edge under the skin to work well.

Just a thought. Slow the rpm down and up the feed rate and deepen the cut if you can and see if it works. Get teh speed right and you can machine hardened steel with carbide tooling.