Who has a Cylindrical grinder to grind some Tungsten?????

cycbb486

cycbb486

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I am wondering if anyone out there that works in a machine shop has access to one?

I am trying to find out about getting some Tungsten ground into a cylindrical shape and a hole bored through.

How hard is it to do and what kind of cost would I be looking at?

The tungsten is for weight to be added to firing pins. The outside diameter is .473". I would have to take the firing pin assembly appart to measuer the diameter of the pin itself for the hole. It is maybe 5/8" in length. When finished it weighs about 3/4 of an ounce.

Thanks in advance.
 
Do you know what alloy of Tungsten you have?

If not, do some reading on it. I think you will be far far ahead of the game springing for some machinable tungsten alloy, so that you can use pretty much standard tooling on a lathe to cut and drill it.

Good luck!

Cheers
Trev
 
The machine shops and I have worked (still do) in few of them don't have tools to drill hole in the tungsten. It's hard to grind outside surface of tungsten as it is. If you find somebody able to do it (EDM?) then you find out than gold is dirt cheap these days.... To add the weight you would be better off to solder brass bushing to fireing pin instead. I know, tungsten is much, much denser, but from practical point of view you have no choice IMHO.
GR8 2c worth.
 
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You would be best to take it to a cutter grinder company (a company that sharpens cutting tools for industry). But hang on to your hat and take the deed to your house and maybe your firstborn with you, because custom carbide grinding is going to cost.
 
I have a few tool and cutter grinders in my shop that I can cylindrical grind with , I dont think I ever machined or ground tungsten other than carbide.
As far as boring the hole goes that might be a problem for me unless carbide could cut it.

A few years ago I could have had a bar of tungsten for free and if I recall the fellow told me it was machineable if it is the same stuff should be ok.
 
I am not sure exactly what kind of Tungsten was used. All I know is the mod I hade done cost a LOT and I figure I could get the weight done up here for less.

Looks like I will have to pay the price to have the second mod done.

Thanks anyways guys.
 
tungsten is likely going to need to have diamond tooling to cut it properly. and "cut" is not the right word, it is grinding. the school i took my cnc programming and tool and die course at they got the students to make tungsten carbide drills, and they had to use a diamond grinding head. EDM would likely be the way to do a hole in the center. the outside would be the hard part.

as others have said, better to use something easier to machine. as tungsten is going to cost an arm and a leg to machine. probably send a $10 firing pin well over the $100 mark.
 
cycbb486 said:
I am not sure exactly what kind of Tungsten was used. All I know is the mod I hade done cost a LOT and I figure I could get the weight done up here for less.

Looks like I will have to pay the price to have the second mod done.

Thanks anyways guys.
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What firing pin benefits from added weight?

Per my last response, look in to some machinable tungsten alloy. Supposed to be not a lot worse to deal with than drilling or turning cast iron. Not gonna find it at Metals Supermarket though either, I figure.

Cheers
Trev
 
TrevJ, if I were to divulge what firing pin benefits............

Let's just say it is a short range BR thing. It is leaving no stone unturned.

Basically, when the REM 700 came out there was a lot of research that went into bringing out such a great action. The firing control mechanism is what it is in a REM. As time progresses people say lets make the pins out of better materials and make them lighter so we speed up lock time. In doing that you must compensate by using a heavier spring. Heavier spring means stiffer bolt lift. In BR stiff bolt lift is bad juju. To compensate weight is added and the appropriate spring used. This aids in a more consistent pin strike on the primer. Some of the top BR shooters have spent a great deal of time working on this.

Most if not all custom actions have been based off of the 700 with slight shape and size changes. Some feel that some of these changes are the causes of ignition issues. Mystic mentioned a while back about that it is a primer issue then. Well trust me, the short range shooters leave no stones unturned and if it were a primer issue I would have heard about it.

Like I said I know it may not be cheap but possibly still cheaper than the alternative.
 
cycbb486 said:
TrevJ, if I were to divulge what firing pin benefits............

Let's just say it is a short range BR thing. It is leaving no stone unturned.

Basically, when the REM 700 came out there was a lot of research that went into bringing out such a great action. The firing control mechanism is what it is in a REM. As time progresses people say lets make the pins out of better materials and make them lighter so we speed up lock time. In doing that you must compensate by using a heavier spring. Heavier spring means stiffer bolt lift. In BR stiff bolt lift is bad juju. To compensate weight is added and the appropriate spring used. This aids in a more consistent pin strike on the primer. Some of the top BR shooters have spent a great deal of time working on this.

Most if not all custom actions have been based off of the 700 with slight shape and size changes. Some feel that some of these changes are the causes of ignition issues. Mystic mentioned a while back about that it is a primer issue then. Well trust me, the short range shooters leave no stones unturned and if it were a primer issue I would have heard about it.

Like I said I know it may not be cheap but possibly still cheaper than the alternative.
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Benchrest theories. OK. That says lots! :D
Lock time and firing pin momentum conundrum.

How many of these weights do you need? Just 1? A dozen or so?

Do you know anyone that has a metal lathe?
Do you know a darts player that would have some old tungsten darts around? IIRC, most of the ones I have seen, are machined, and I would bet my last buck that they have never been near anything as high tech as an EDM machine.

I am working under the idea that the weights are either pinned, press fit, or secured with adhesives.

A stroke with a file will tell you quick as anything, if the material is going to be machinable or not.

Cheers
Trev
 
Pei, they have issues as well.............

I thought with all the so called expertise around this forum there might be someone who has the know how. I see that is not the case.

Well I guess a call to California is in order.
 
After looking at the weight that was added to my firing pin it must be machinable tungsten. If it were not I would hazard a guess that a hand engraver would not be able to mark it?????? There was an arrow scribed on the weight so it must be machinable.........

Thoughts?

photo_zpsc48896b2.jpg
 
How about a longer cocking piece I know its on the other end but its simple to do to an old firing pin, just tig a piece on and machine it shorter until you find a change. At first I was going to say "until your happy" but we all know the answer to that :D You could use a threaded piece and add nuts.
 
I know this is not pertinent to the question asked by the OP, but I was curious what the current line of thinking in BR circles is w.r.t. firing pins. Are you simply trying to add some weight to the firing pin? If so, what is the reason for wanting to use tungsten to do this? I can understand if you needed the added weight to be very small in size (tungsten is quite a bit denser than steel), but do you have a space problem you're working within?
 
If I understand it correctly, it's a matter of tweaking milliseconds or microseconds for the firing pin and it's momentum.

Another means to the original end has occurred to me, that avoids much in the way of machining, is to simply part the firing pin off and silver solder a section of suitable diameter tungsten or tungsten carbide rod in there.

Silver solder will hold pretty well, and the shanks of carbide milling cutters could be used as donor stock. They are available in shank sizes in all the fractional and full number metric sizes, and, failing that, a straight cylindrical grind of the outside, is much easier than dealing with the need to punch a hole through the center to fit it over the outside of the pin. There are also carbide drill bits and drill or reamer blanks to consider.

A small lathe would be really handy for this, but a fella with a drill press and a Dremel tool, and some diamond grit disks, could accomplish a lot for pretty cheap, I suspect.

Cheers
Trev
 
If the goal is reduced lock time, that can be achieved by one or more of:
- stiffer spring
- lighter moving parts
- shorter travel

I am not understanding why tungsten is part of the solution (it's dense and it's hard to machine; you wouldn't put up with 'hard-to-machine', unless there was a good reason that you needed 'dense')

Given that BR needs to be able to cycle the action quickly without torquing the rifle too much, it's important that bolt lift effort be not too heavy and that the force profile should be smooth. I can understand how firing pin travel, spring force, cam angles, bolt throw rotation all play into this. And while these factors are related to firing pin assembly mass, I don't see how they are related to the density needed for a particular portion of the firing pin assembly.

Most likely, I am missing something about the goal being sought.
 
rnbra-shooter said:
I know this is not pertinent to the question asked by the OP, but I was curious what the current line of thinking in BR circles is w.r.t. firing pins. Are you simply trying to add some weight to the firing pin? If so, what is the reason for wanting to use tungsten to do this? I can understand if you needed the added weight to be very small in size (tungsten is quite a bit denser than steel), but do you have a space problem you're working within?
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I am not the person who will be able to explain this in the most efficient manner. If you read the OP basically everything is in it. The question is why Tungsten? Remember fellas the firing pin is only so long. You need a spring in there and still a spring that will do its job effectively. The weight needs to be as heavy as possible in the smallest size possible. Unless you are into the game of BR most may or will be skeptics about ignition. It is not about lock time. It is about how consistent the firing pin strike is to the primer.

I hate typing all these details out.

Trevj doing what you suggest is out of the question in regards to my BR rifles.

All I was wanting or looking for is someone up in Canada who may be able to help. I can have all the work I want done states side but you guys know all the legalities of shipping rifle parts across the line. I was just trying to give a Canuck some work.

I have done some research and there are places in the US who can do what I am looking for. That is the route I will have to take.

Again it is not lock time, it is a consistent heavy strike, You can use a heavier spring but that increases bolt lift which is bad JU JU in the BR game. Like I said everyone wants an aftermarket light weight firing pin, bad JU JU. Rem did there reasearch before they came out with the Rem 700. The TOP BR shooters know what works. You need to get into the game to understand it. It is a lot more high tech than you think. Anyways thanks for the time and efforts.
 
There should be no restrictions on a tungsten bushing... it isn't really a gun part... import a few and sell them...
 
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