Stretching a hand

[OD#3]

So I noticed that the timing on my latest New Service was just a tad late, the bolt failing to reliable enter the notch when cocked very slowly. Having taken delivery recently of the appropriate manual by Kunhausen, and having studied it carefully, I began the process of stretching the hand. Trouble is, these things are HARD! Rather than peening the hand, the hand peened my blunted cold chisel. Since it had been so long since I'd blunted that chisel, and thinking that perhaps I'd failed to harden it properly, I reshaped and rehardened it by heating it cherry red and water quenching it. The result? The hand destroyed the chisel again. I may have to get a new hand eventually, and since they're so scarce, I'll probably have to settle for one of the repros at Numrich. In the meantime, I had some success using a center punch several times in a line accross the thin part of the hand. It didn't stretch it very much, but it was enough to correct the timing, and it has stayed correct after seating. But because I had to use a non-recommended way to stretch the hand, I don't entirely trust the job. Anyone know anything about the quality of the New Service hands from Numrich?

[smkummer]

Sorry can't comment on the hands from Numrich, but its good to know they have them. Your hand streching experience is exactly like mine. I also peened a chisel and had to use a punch with several hits to make due. I did finally get a hardened chisel that worked! In fact it worked so well that I "cut" in two my first hand. After finding a small cache of used hands (for python/official police) and flattening the sharp chisel like shown in the book, it now works very well. For those that are reading this, Colt told me that the double action parts they had on hand were for their use and not for sale at this time. Jack First is now making hands for E/I frames at I believe about $35 plus $9 shipping.
FWIW, every Colt that I had to stretch the hand, never went out of time again in my service.

[OD#3]

Thanks; you've eased my mind quite a bit--especially the part about yours not going out of time again after you fixed them. I think I'll have to pick up a new hand or two anyway though, since I just don't know how much longer they'll be available. Its been really irksome to visit Colt parts websites, find parts for the most obsolete of Colt firearms, yet see nary a one for the New Service. Shame that they had to let the machinery rust during WWII.

[Oyeboten]

I would have thought it best to anneal and then Stratch a Hand, and, then, to re-Harden and Temper it..?

[OD#3]

That seems like a sound idea at first, but I think that whatever you gained in ease of stretching would be paid for by how difficult it would be to re-harden and temper it without warping or other such dimensional issues; the web that gets peened is much thinner than the rest of the hand, and I think heating and quenching could cause it to bend in unpredictable ways. I'm also pretty sure that the specific hardness and temper of the hand as specified by Colt would be very difficult to duplicate as well; it would be nothing but guess work. Even though the center punch that eventualy worked was one I'd ground and hardened myself, I was unable to produce a satisfactorily-hardened blunt chisel for the recommended stretching procedure. And these two tools were made from the same type of steel, having both originally been part of a cold chisel and punch set. I can't even seem to get two tools to the same hardness, using the same heat-treating procedure for both. There's no way I'd try heat-treating a hand.

[dfariswheel]

I found that the best way to stretch a hand is to put it on a no-bounce anvil.
Things never work well when your bench or bench block are bouncing around due to lack of firmness.
If necessary, put the work on a concrete floor.

I had a really firm work bench and i used a section of rail road rail for an anvil. This made stretching hands easy, but once in a great while one would just break.
This is a hazard of hand stretching, and in the days when new hands were available it was no big deal.

[Boge]

I stretched a hand once by putting it in a vise and using a fire damaged 45-70 barrel as a "cheater" bar!!

[rhmc24]

If you want to anneal it - heat it red and let it cool in air. To re-harden, heat it red and quench in motor oil which will probably be too hard to file. I would give a spring temper by put it & a little oil in a metal dish, heat from the bottom till the oil catches fire and let it burn off. That gives a spring temper, not as hard and not brittle. I use SAE 30 oil and make a little dish by cutting about half inch high from bottom of a food tin can, then beat the bottom so it will be almost flat with a little dish to it to keep the oil from running away to the edges. Half a teaspoon full oil is plenty. Handling a small part like that while h0t, I tie a loop of wire around it. As with any new procedure it is a good idea to do a dry run on scrap to check it out.