HomeSmith: Long Tom SAO conversion

Shotguncoach · #1 04-14-2024, 02:43 PM

It's been a while since I did a new HomeSmith project and I had a few extra hours this morning, so here is Long Tom.

Long Tom is a "no dash" Model 14 from around 1960. He is purely a range toy. If I'm going to go to the trouble of carrying a revolver with an 8 3/8" barrel it's going to be something with the word 'Magnum' in the caliber. Tom wears a set of Herrett target stocks and spends his life punching holes in paper. As such, I think I've only ever fired Tom double action once or twice.

I've already been inside and performed a basic fluff and buff. With a Wolff hammer spring, 44 ounces of hammer tension, and a 12 pound Wilson rebound spring Tom had a double action pull of 8 1/2 pounds and a single action pull of 2 1/4 pounds.

As an aside, Tom groups quite a bit better with 158 grain LSWC's over 3.5 grains of Bullseye than he does with Federal Gold Medal 148 grain factory wadcutters. Go figure...

Shotguncoach · #2 04-14-2024, 02:52 PM

I've seen lots of references to SAO Model 14's and since that's really the only way I ever shoot this one I thought it might be fun to try. I picked up a singe action only hammer from flea-bay and I was ready to go with my experiment. (Those of you who already know just hush....)

Before we start this adventure, let's document the relationship of the double action hammer and trigger at full cock and at rest. The hammer block was removed just for visibility.

Shotguncoach · #3 04-14-2024, 03:04 PM

The single action hammer from flea-bay had some pretty significant drag marks on the right side but that helped make it cheap.

The original hammer came out and the new hammer...didn't want to go in. This way, that way, hold your mouth just riiiiiight, and there it goes.

And now nothing moves. I believe the German word for how locked up the action was is "Gutenteit".

I tried a few different installation orientations and even had the emotional support llama give me a hand, but it always ended up with the hammer and trigger locked together with no movement.

Fail.

Everything came apart again, the original parts were all reinstalled, and I went to do more research. My google-fu eventually paid off with a hit on a thread here that the site search hadn't picked up the first time around. There was a special trigger that was supposed to go with the SAO hammer that conveniently gets forgotten in most discussions.

Yet another chapter in the story of my life which will be titled "Why should this be different?"

Shotguncoach · #4 04-14-2024, 03:15 PM

I didn't post about this when it happened because there wasn't much to talk about except failure. So I waited...

A few months later I was searching for a barrel to replace a bulged barrel on a 5 screw K38 (project Muffin Top...you'll meet that one later) and I ran across a single action only parts kit. Not only was there a good barrel, all the action parts were included.

And the trigger looked different....hmmm. Let's give it a shot. (har har)

Here are the pieces from the kit, and a view of the original hammer (top) next to the trigger from the parts kit (bottom). There's a pretty significant difference that is easy to spot once you know what to look for. There's no cam below the sear on the single action trigger.

Shotguncoach · #5 04-14-2024, 03:47 PM

So here we are at today. The original insides were moved to the outside and the original hand was transferred to the new trigger.

It's amazing how much better things fit together when you have all the right parts.

Timing with the old hand/new trigger combination is just a touch slower than it was with the old trigger but it's still in spec. The cylinder stop locks in just slightly later that I would like, but it still happens before full cock and that's with a slow-motion action cycle with my finger dragging on the ejection rod. At the range with the extra weight/inertia of a loaded cylinder and a snappy cocking action very few people would notice.

I know that I'll have to pull it all apart again to get the rest of the corrosion off of the replacement trigger, so I'll try the hand that came with the kit when I do that and see if it improves the timing. The trigger stop could also use some adjustment to work with the replacement trigger. For today we're really just finding out if I like this setup. Fine tuning and making it pretty can happen later.

With absolutely no work on the replacement hammer/trigger other than a quick wipe down, we ended up with a 1 3/4 pound single action trigger pull that feels amazing.

Range report to follow tonight....

Shotguncoach · #6 04-14-2024, 04:01 PM

There's something I'm wondering about that perhaps our more experienced members can help me with...

I've seen several mentions of a short action single action hammer and trigger, but this set appears to have the same hammer throw as the original set. The way the short action single action was described HERE, I was expecting a shorter hammer throw after the conversion.

Since the hammer throw is the same as it was with the double action hammer, it occurs to me that I may have ended up with a double action trigger that has been modified to work with the single action hammer and I still don't have a true short action single action conversion. What does the hive think?

Protocall_Design · #7 04-14-2024, 04:20 PM

You have a hammer that was originally made to be single action only, as evidenced by no provision (slot or pin) for a double action sear, and no secondary DA cocking notch. Compare the length of the sharp inside corner on the SA hammer directly below the spur to the length of the same place on the SA/DA hammer. The SA hammer may be wider there, meaning it doesn't cock back as far. Measure from the corner to the front of the hammers. They may be different, I'm not up to speed on all the older stuff.

Edit-I see you said double action trigger, and I answered for DA hammer. I think you probably have an SA trigger as well.

Shotguncoach · #8 04-14-2024, 10:52 PM

Well that was frustrating.

Mechanically everything worked fine and the gun went bang every time.

Functionally? I'm not sure that I could hit the ground if I dropped it.

I shot normally with the other 3 guns that I took with me, but this one developed a bad case of the randoms. It went from normally all in the black to randomly throwing shots out into the white past all the scoring rings. I have no clue why.....
Switching to a different gun brought everything back to normal. Go back to this one and no clue where the shots are going to go.

It was very strange. I was shooting tighter groups with a pencil barrel 10-5 than I did with this one.

So...it's time to start over. I'm going to undo the changes and put everything back the way it was and see if the random fliers go away. If not, then I know it wasn't the change I made today. If it goes back to normal, then the next step will be to put the SAO parts back in and see if the random fliers come back.

I'm pretty sure the problem is with me and not the gun, but we'll find out over the next few weeks. Stay tuned.....

Protocall_Design · #9 04-15-2024, 10:27 AM

Lockworks parts don't make it shoot randomly. It has to be something about the cylinder or barrel. Maybe the barrel has a constriction or bad forcing cone that got it leaded up. It started out fine, so something got progressively worse.

Shotguncoach · #10 04-15-2024, 01:23 PM

I’ll do a complete checkout on the gun itself, but I’m pretty sure that the problem was somewhere between my ear plugs.

stantheman86 · #11 04-15-2024, 08:35 PM

I used to have an 8 3/8" 14 SAO and I always wondered what the advantages of not having a DA hammer dog were and why people didn't just use Target Hammers, and not use them in DA

Shotguncoach · #12 04-21-2024, 11:54 PM

It was a wonderful Arizona spring afternoon...

So I packed up Long Tom and a few friends and headed out to the range.

And it turns out that my problem last week was an L-O-T issue.

Lack

Of

Talent

Today was much better. Upon reflection, I think the real issue was that today I ate lunch and last week I didn't. Little things make a difference.

The next steps will be to move all of Tom's insides to the outside and clean up the spots of corrosion on the SAO hammer and trigger. The original hammer and trigger did not go into the parts pile....they're in envelopes marked with the serial number in the back of the safe.

One other thing that I noticed about the SAO parts is that with this setup I can run an 11 pound rebound spring and still get a snappy trigger reset. Will I be rushing out to find more SAO parts? No, probably not. It's fun to have though...

Protocall_Design · #13 04-22-2024, 08:52 AM

Good shooting! The quilted grips are interesting, haven't seen that before.

Shotguncoach · #14 04-22-2024, 09:50 AM

I picked those up on flea-bay just because I hadn't seen it done either. They turned out to be surprisingly comfortable and work quite well on a K-22.