Howdy
In my experience, you cannot take a Single Action Army apart with just one screwdriver. It is always best to use a screw driver, or screw driver bit that is the same width as the diameter of the screw head. The slots on gun screws tend to be quite narrow, so the screwdriver tip needs to be thin. Also best if it is hollow ground, meaning the sides of the bit are parallel at the tip. Hardware store screwdrivers tend to be wedge shaped, which means they naturally want to try to climb out of the screw slot when torque is applied, a good way to bugger up the screw head. Anyway, the head of the screw fastening the hammer spring to the grip frame is larger in diameter than any of the other screws and it is best to use a wide screw bit to loosen this screw. Using a narrow bit can result in the tip bending or breaking. Trust me on this. The grip screws, all inserted into their respective holes in the frame in this photo, sit in counterbored holes, so a bit must be used which fits down into the counterbore without scraping the sides of the hole.
This is my collection of Brownells Magna-Tip screwdrivers. It is not necessary to have this many bits to take a SAA apart, you can buy a handle and with 3 bits from Brownells that will specifically fit all the screws in a SAA. I have a lot of guns, made by many makers, so I like to have a large variety of screw bits handy.
Regarding broken parts in a SAA, the broken trigger/bolt spring at the top of this photo is the part that breaks most often in a SAA. This is the way this part typically breaks, right at the base of one of the legs, where the metal is stressed the most as it flexes. The broken bolt is somewhat unusual. Notice where it broke, right at the two narrowest cross sections 180 degrees apart across the hole. This part is made of spring steel, the broken arm flexes every time the hammer falls, and over time metal fatigue set in and it broke. By the way, this is not a drop in part, it took an expert gunsmith (not me) about an hour to fit a new one.
The other spring that commonly breaks in a SAA is the hand spring. It is peened into a slot in the hand. This spring tends to break right at the sharp curve where it emerges from the hand. When this spring breaks in an Italian clone, one can buy a new hand with the spring attached. Again, the new hand may not be a drop in part, it may need to be fitted. I have found it is easier to drive the remainder of the broken spring out by driving in a new spring. Then no fitting is required to a new hand.
The Remington 1875 and 1890 action is very similar to a Colt SAA. The hand only has one point instead of two teeth of the Colt hand, and since the grip frame is not two separate pieces there are fewer screws. Also, the Colt hand pivots in the hammer by way of a pin on the hand inserted into a hole in the hammer. The Remington hand is screwed to the hammer. The hammer cannot be removed until it is lowered far enough in the frame allow the hand screw to be unfastened, then the hammer can be withdrawn through the top of the frame. Both the trigger and the bolt on the Remington pivot on the same screw, so that makes for one less screw in the parts count.
When Ruger started making his Three Screw Single Six and Three Screw Blackhawks in the 1950s, he substituted wire coil springs for the leaf springs of the Colt. Coil springs are almost unbreakable, because the flex is spread over the entire length of the spring instead of one narrow spot in a leaf spring. The action of the old Three Screw Rugers worked almost exactly the same as a SAA, but the parts count went up because each coil spring needed a plunger to go along with it to present the spring force to the appropriate part.
When the New Model Rugers with transfer bars came out in the mid 1970s, the part count went up again. By the way, I can almost take a Colt apart and put it back again blindfolded, it's that easy. Putting one of these back together again is a pain and usually involves some gnashing of teeth.
I don't like to take an antique Smith and Wesson #3 Top Break apart all the way. I just remove the parts that can be taken out with a screw driver, I don't like to drive out the pins the trigger and bolt rotate on.
I don't have an exploded view of all the lockwork parts in a modern Smith and Wesson, the next time I take one apart I will have to take one. I use a couple of different sized screw drivers to take one apart, and a special tool to shove the rebound slide spring into place in the rebound slide during reassembly.
