James, 3 1/2 percent nickel is an excellent filler metal for welding bolt handles. It's 80-90 ksi ultimate tensile strength, has excellent toughness , and great weldability to boot. I think it's prone to come out purplish (plum) color if you blue it tho, and I haven't tried parkerizing it yet. It's been many years since I used to blue guns (caustic hot blue), but I think that it was usually nickel content that caused parts to come out like that. If you do blue it, I would like to know how it looks.
Jim, ER 309 and INCO 82 are also very good choices if you want to use an austenitic filler metal for its toughness, strength and weldability, but they won't blue.
Kirk and James: If you weld on any assembly that was silver brazed originally, like Remington bolt handles, it is necessary to get absolutely every trace of the silver off before welding (no matter what kind of filler metal you use), otherwise it will spit, blow, smoke, crater, and may cause small cracks in the weld itself.
Kirk, silver brazing is about 1/2 science and 1/2 art. Don't be too hard on yourself. You would be amazed at how many skilled weldors can't do it right.
Man I'm long-winded.
Good luck, Tom
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