I've seen them done without a tube so it can work either way.@AlNyhus Thank you. I like the weight attached to the butt plate. What is the function of the tube?
Yes, I've done o-rings and found them to be more trouble than they are worth. Dang thing can be hard to get in and out if the seal is tight enough. Might be that is what was rolling the o-ring off of the rod. The tubing I use is usually just a few thou or so over the od of the copper tungsten rod. So, a piece of electrical tape only wrapped about 3/4 of a full turn around the rod leaves a little space for air to escape and keeps it snug in the tube at the same time. Like I said previously, this can be easy or hard...your choice. But yes, o-rings can work too.I actually cut some grooves in a piece of aluminum round stock to try that. Every time I pulled the weight out, the 'o' rings wanted to stay in the tube. -Al
Might need a little oil and a closer fit between weight and tube. A nominal 1/8 o-ring needs a groove .120-.125 deep from the ID of the tube. So, with .010 clearance all around, the groove would be .110 to .115. deep and .125 wide. I guess electrical tape is easier! WHI actually cut some grooves in a piece of aluminum round stock to try that. Every time I pulled the weight out, the 'o' rings wanted to stay in the tube. -Al
It's adjustable if ya stretch it tighter, it gets thinner. Lol! It does make things easy is all.Might need a little oil and a closer fit between weight and tube. A nominal 1/8 o-ring needs a groove .120-.125 deep from the ID of the tube. So, with .010 clearance all around, the groove would be .110 to .115. deep and .125 wide. I guess electrical tape is easier! WH
LOLIt's adjustable if ya stretch it tighter, it gets thinner. Lol! It does make things easy is all.
Now that's funny! Gotta know the story but funny. Thanks! I needed that laugh.LOL
Now your sounding like a “famous” RF pundit
Next thing you know you’ll be drawing cartoons to explain it to us!
We are BR shooters, we don’t do anything the easy way!
G
I’ve used 93/7 and it wears out a few bits before you’re done. I tried drilling and tapping a nice piece of pure tungsten I got once and gave up on that quickly! I ended up putting it in a copper tube and pouring lead in around it with a S/S plug for the screw. Worked great but more effort then is required.70/30 machines very well with standard tooling. 80/20 isn’t horrible but I wouldn't go any less.
The copper alloy helps a lot. I found and bought a piece of tungsten and used it ONCE. Not tungsten carbide, but tungsten rod. It was tough as hell but I did manage to get a hole in t and tapped. It cut in a bandsaw, actually pretty well but other machining ops were tough and yes, it was a lot like cast iron, as it appeared a sintered material, fwiw. But as Al said, the 70/30 machines pretty good and is actually easier to find anyway than that tungsten rod was. I prefer the 70/30 over the 80/20/ The 80/20 gets pretty hard to work with. I think technically, it's Tungsten copper, where the big number is the tungsten..fwiw. And even the alloy cuts a bit like a really tough brass, somewhat like cast too, just no nearly as difficult to work with, ime.![]()
COPPER TUNGSTEN
Tungsten Copper Electrodes For Resistance Welding, EDM, and Plasma Spray, Heat Sinks, Heat Spreaders. (W Cu, Cu W) 50 50, 60 40, 70 30, 75 25, 80 20, 90 10.www.chemetalusa.com
From what I've read, where ratio of copper to tungsten favors copper it is easier to machine, but generally it machines like gray cast iron.
You only have to play with the 100% stuff once, and that's enough for most of us.The copper alloy helps a lot. I found and bought a piece of tungsten and used it ONCE. Not tungsten carbide, but tungsten rod. It was tough as hell but I did manage to get a hole in t and tapped. It cut in a bandsaw, actually pretty well but other machining ops were tough and yes, it was a lot like cast iron, as it appeared a sintered material, fwiw. But as Al said, the 70/30 machines pretty good and is actually easier to find anyway than that tungsten rod was. I prefer the 70/30 over the 80/20/ The 80/20 gets pretty hard to work with. I think technically, it's Tungsten copper, where the big number is the tungsten..fwiw. And even the alloy cuts a bit like a really tough brass, somewhat like cast too, just no nearly as difficult to work with, ime.
There may be some tricks to working with it that will help. My experience machining it is limited to these weight systems, so certainly not extensive at all.
It is on the expensive side but it just works se well as a weight in a small space. Sounds like you know it better than me but being roughly 1.5 times as heavy as lead, it's about as dense as there is without raising flags from the feds. Imagine explaining you're just using this piece of uranium rod for a weight in a gun stock to homeland security. Lol!You only have to play with the 100% stuff once, and that's enough for most of us.
Yes it is a sintered material, I am not quite sure how they introduce the copper into the alloy.
The .825 round bars of W93/CU7 (claimed) I got a few years back was purchased from a
scrap metal dealer in Tel Aviv.
The amusing thing was he landed it in to me for about about 1/3 the cost I could get it here in the states.
Go figure.
G