K-Frame Bolt Spring Collapsed?

[ContinentalOp]

I'm having an issue with the bolt spring on my 2" 64-4.

I bought it used. Both the FFL dealer and I inspected it, and all was well. I took it to the range and after a few cylinders the cylinder release latch came off...with the screw post still attached. It was then I noticed that there was a lot of forward and back play of the bolt in the frame. The bolt plunger was not pressing firmly against the back of the frame slot. I figured it was a bad bolt spring.

I got a new bolt and bolt spring. Everything's fine for the next couple hundred rounds.

I went shooting this morning and towards the end of my session I noticed the 64's cylinder release latch was moving back and forth pretty freely. I took it home and opened it up, and sure enough, the bolt spring was not pressing the plunger against the frame. Here's a picture of the bolt with the plunger on the left. Yes, the plunger is in the bolt with the spring. However, this time I can't get the spring out.



I have four questions.

1. How do I get the old spring out? I've tried using a paper clip, a punch, and spraying Gun Scrubber in the hole to loosen it without success.

2. Is there something else going on that I'm missing that could have caused this repeated failure of the bolt spring?

3. Is the bolt spring the wrong diagnosis?

4. How do I fix this so it doesn't happen again?

Any other suggestions would be appreciated, too.

Thanks in advance.

[john traveler]

The bolt spring is what provides the bolt with forward tension to push against the cylinder center pin.

If your bolt spring is kinked (or broken) you will get the symptoms you described.

Removal is with a flattened paper clip tip or a small screw driver that will just jam into the spring and bring it out when withdrawn.

Kinking of the bolt spring during installation can cause this failure.

[ContinentalOp]

OK. That makes sense. Thanks for the help. I'll get a few more springs (for back-ups) and take extra care during installation.

[ContinentalOp]

Originally Posted by john traveler

Kinking of the bolt spring during installation can cause this failure.

Are there any tips/tricks to installing the bolt spring without kinking it? Could kinking it have happened when I installed the bolt back in the frame? Any tips/tricks on that part of the job?

Thanks again for any advice.

[Rule 303]

More than likely a bad spring.

I use a dental pick to remove mine when this happens.

Rule 303

[HeloMt]

You may also have a burr in the hole where the spring and plunger reside. Check for any binding prior to reassembly with a new spring. Plunger and spring should move freely. A small brouche might remove an offending burr.

Randy

[Damn Yankee]

How could you kink the spring when the plunger is compressing it in the hole?

[ContinentalOp]

Update:

I was able to get the old spring out using a dental pick (thanks for the tip!). I received the new springs I ordered and put them in with the plunger and the end of the plunger barely stuck out of the bolt. So now I'm curious about what's going on. I took the bolt out of my 65 and used a paper clip as an improvised depth gauge to compare the plunger holes in the two bolts. It looks like the 64 bolt was nearly twice as deep as the 65 bolt.

Out of curiousity I compared the original 64 bolt (the one that broke) with the replacement 64 bolt (the current one with the issues) and they both have the same depth. Here's the interesting part. When I removed the paper clip from the original 64 bolt, a small spring came with it. It looked to be about half the length of the new bolt plunger spring.

I'm at a loss now about what's going on. Do I need to replace the bolt again? If so, how do I make sure it's the correct depth? Or do I use the mini-spring from the original bolt along with the new spring and the plunger?

I hope someone can give me some advice on my next step, besides "take it to a gunsmith" (I'm trying to save that for a last resort). Thanks in advance.

[m1gunner]

I have run into what you are seeing. Some of the bolts I have take a longer spring than others. Don't know why, and see no mention of different length springs in the parts lists.

[scooter123]

Just a couple of thoughts here. Since you have 2 different guns that allow you to determine the depth of the bore for the current spring that works well, you may want to pay a visit to a machine shop and have a small plug made to shorten the depth of the bore in your model 64. If you decide to take this route, I would suggest that you have that "filler plug" made with a small tapped hole in the center to make it easier to remove. I'm thinking a #2-56 thread but that's a pure guess, ideally you want to choose a thread size that is that same as, or just a tick smaller than in inside diameter of the spring. You will also want that plug to be a somewhat loose fit in the bore so that it will come out easily.

Another option is all home brew. If you check industrial machine shop suppliers you'll find that many sell something called "gage pins" in 0.001 inch increments. Sources that I've used for items like this are Production Tool and MSC Industrial Supply and you can find their web site with a simple google search. Measure the outside diameter of your spring and subtract 0.003 inch from that dimension, BTW use either a micrometer or caliper to measure the diameter because "eyeballing" it won't do. Then order a gage pin at that diameter, cost is about 3 bucks. BTW, a drill bit of the correct size may also work, however drills don't come in 0.001 inch increments unless you custom order them, so you may not be able to find a drill that is perfect in diameter. Once you have you pin stock, it's then a simple matter of cutting it to length with a Dremel and a cutoff wheel. BTW, make sure to deburr it after cutting it to length, you don't want a burr that will cause it to get stuck in that hole. Once you have the filler plug made, make sure to COMPLETELY clean the spring pocket of any trace of lube, otherwise that lube may prevent in from falling out freely should you decide you need to remove it.