Most of the people reading this probably have an old rimfire from their dad or granddad that is older than the hills. Maybe that old rifle will shoot and maybe it won't.
This little rimfire was found at my local gun store for $50. It is a 1924 Springfield 52-A. It was the oldest, dirtiest, and simplest gun they had. I thought it would be a good project gun. My son can have it when I am done with it, since it is light and points well.
The first thing to do upon getting it home was making sure the barrel was clear of obstructions and seeing that everything worked. I was not worried about cleaning it because this project was about start-to-finish results. The firing pin was bent, but I decided to test it as-is since technically it did sort of work. It was very difficult to move, but I wanted to see if it would even fire. I will discuss the firing pin later on. The barrel was clear, so I fired a few groups with CCI Quiet ammunition, which lived up to its name. It shot 5/8 to ¾ of an inch at 10 yards, which is about what I expected. The trigger was very heavy and rough, a far cry from my CZ 455 which breaks like glass at 8 oz. The first order of business now was to scrub the barrel squeaky clean with a good brush and lots of solvent-soaked patches. This took some time. That barrel was filthy and full of pits. I decided to go on ahead with the project in spite of the pitting, since I had heard from a respected gunsmith that a pitted rimfire barrel can still shoot well in most cases.
The crown was the next order of business. I took the rifle out to my wood lathe to cut a new crown. I know what some of you guys are thinking, you can't turn metal on a wood lathe. Well, I can tell you that you can if you know how and are careful. My lathe is equipped with a 4 jaw chuck, which comes in very handy for projects such as this. I used a freshly sharpened tool to cut a new crown. There is enough pitting in the bore to prevent a perfect crown, but it is worlds better than the old one.
A good file can be used in place of a lathe, or you can rent a crowning tool from a number of websites. The alternative would be to take the barrel in and have any good machinist turn a fresh crown for a small fee.
The third order of business was to fix that firing pin. It was bent so far that it did not want to move in the bolt body with finger pressure. I don't know how it got like that, but it wasn't good. I removed the pin from the bolt and straightened it. The sides were trued up on one of my stones to make sure it was straight and smooth.
You can see in the picture above how bent the pin is. The straightened pin dropped right into the slot and moved along the groove with a gentle tipping of the bolt, just as it should.
I filed a groove in the firing pin face face to move the impact away from the edge of the rim and added a bit of material to the tip to make it bit longer. This gives better ignition by allowing the pin to completely crush the priming compound and prevents the pin from losing energy on the solid brass rim. Getting the pin off of the rim also reduces barrel vibration.
Below is the new firing pin face and the dent that it makes. This gives much better ignition, which means better accuracy.
One thing I want to note about this rifle, is the firing pin location. When the bolt is open, the firing pin is at 6:00. When the bolt is closed, the firing pin moves to 8:00. I feel this to be better than a 12:00 pin because the primer burst is closer to, or even in the powder, improving ignition.
I cleaned up the bolt, receiver, and trigger, and gave the rifle a good overall wipe down. I did not do much to the trigger. It was tempered to a very hard surface and my file would not even scratch it. I will use a fine grinding stone on it in the future, it works fine for the time being. I assembled the rifle and took it outside to try it out. I set a target about 15 yards away and sat at the picnic table with a handful of CCI Quiet, just like before. I shot a 6 shot group (I didn't count very well) and was not impressed with the results. I shot a 5 shot group and things started to come together as the bullet lube coated the barrel. The third group was amazing with 4 shots going into the same exact hole. I pulled the fifth shot and it landed a bit below the group.
I have to say, I am very pleased with the outcome of this project. This kind of work is not outside the scope of the average 'do-it-yourselfer'. I think I am supposed to say that I am not responsible for any damages if people try this. There, that's out of the way. I hope this sheds some light on a few things. I enjoy helping others and answering questions. If anyone has questions or comments, feel free to comment and I will do my best to get back to you.