Thread size for model 1917 ejector rod

[Militarygunguy]

I have been restoring a rust bucket model 1917 into something shootable.
I found a military parts kit and changed everything over to US Army parts. I managed to over tighten the ejector rod while making some adjustments and snapped it off I side the extractor. I used an easy out to remove it. The threads look fine. I ordered a replacement from popperts with the correct mushroom head and RH threads. The issue I am having is that the rod screws into the extractor about 1 1/4 turns and then stops. Obviously I don't want to force it. Does anyone know the thread size for the extractor so that I can chase the threads and make it all fit? Or can I cut new threads on the ejector rod? Any info would be appreciated!

 

[Wiregrassguy]

Welcome to the forums from the Wiregrass! According to the parts listing at Numrich, there were 3 different versions of the extractor rods used on the M1917. Perhaps if you post the serial number of your gun and some pictures of both rods you have, an expert can tell you if you have the right replacement

 

[Militarygunguy]

You are correct

There were three different variants of extractor rods used on the 1917..the one that it originally had was the early model with RH threads. The replacement also "looks" like an early model as well. They both have the mushroom head..definitely not a 2 piece, and not the later variant with the straight tip.

PS thank you for the welcome

I posted a pic of the rod. The serial number for the cylinder and related parts are:
Cylinder number - 38367
Barrel number - 38367
Extractor number - 38367
Frame number - 46492
Serial number - 168183
Yoke number - 69783 (not sure)

This was originally a Brazilian that I replaced most all of the parts with a US Army version. So it's a total mismatch

 

[StrawHat]

This is the first I have heard of three different threads for the Model 1917! I have quite a few from 1917 up to the 40s.

I will grab four of them, see if the ejector rods swap, and post the results.

Kevin

 

[Wiregrassguy]

Kevin, we didn't say that the rods had different threads. There are three different versions and how they are different is not clear to me. But one difference could be the threads are different. The OP has posted that he used early military 1917 parts in a Brazilian gun. Any of the mushroom shaped rods will have right hand threads. So worrying about the thread direction is immaterial.

 

[steelslaver]

I thought that except for early ones being right hand and later left hand and there being various tips that was it.

It is possible the threads go a bit tweaked during the over tightening

I have taken pieces of round plastic and even hard wood dowel and threaded them into holes and then used a pitch gauge to figure out the threads per inch

I have been amazed by the odd ball taps and dies I have found available on Ebay. I recently got a 11/16-18 die and used it to make a tool to remove a aftermarket Polaris clutch. 9/16-32, got one, 5/16-32, got one, 3/4-24, 9/32-32, 3/32-48

 

[mikepriwer]

Early K-frame extractor rods have a RH 10-48 thread, where it connects to its bottom half. I would expect that N-frame rods ought to be the same. Locking up after 1 1/4 turns is an indication of the wrong thread pitch.

Mike Priwer

 

[Militarygunguy]

Thank you for all the replies so far

And thats what I am thinking. So if I can figure out the correct tap, I can chase the threads so that it functions again. Literally all of the parts minus the frame were replaced with US Army period parts. And the old rod snapped inside the extractor. I didn't have to do much work to get it out. Possible it was damaged a bit before I installed the old one.

 

[Wiregrassguy]

According to a thread chart I have, the 1st Model .44 HE extractor rod stem has the following dimensions:


Diameter: .186"
Pitch: 47
Tapping size: .1674"


Now I know there were some changes from the 1st model N frame to the 2nd. But I don't have any reference that shows the dimensions of the 2nd model extractor rod stem.


By the way, those dimension are the same for the M, I, and K frames.

 

[Militarygunguy]

Outstanding

Ok so dumb question, based on the dimensions, a 12-28 tap wouldn't work then. I would need a tap with 47 TPI?

 

[Wiregrassguy]

If you are asking me, it's not so dumb a question. I'm not a machinist or gunsmith. Basically, I'm a librarian. All I know is S&W did not use standard threading on its screws so you can't use off-the-shelf taps. I doubt a tap with 47 tpi is routinely available. But, fortunately, there are a number of gunsmiths and armorers here that can likely help.

 

[Militarygunguy]

I wouldn't even mind paying someone to clean it up, versus finding an obscure tap that I will only use one time or having to buy and fit a new extractor.

 

[Wiregrassguy]

What are the conditions of the original Brazilian extractor rod and extractor star? I presume the cylinder was too fouled up to use and that's why you substituted WWI parts. The extractors were fitted to the cylinder and the hand. But that doesn't necessarily mean they won't work in the new cylinder...might require some fitting.

 

[Militarygunguy]

I was trying to post pics of the gun as I received it. Everything looked like ****. Rusted and pitted. I sold off all of the parts minus the frame and started over. So unfortunately I don't have the originals anymore. I don't mind fitting. I replaced the barrel and set the forcing cone gap already. But spending maybe 100 on a tap to chase threads as opposed to buying and fitting a new extractor, I would go with the lesser of two evils if possible

 

[Militarygunguy]

Original

Some shots before and current

 

[Wiregrassguy]

Well, I'm out of my depth. Perhaps your solution is to buy another extractor and hope it works. Best of luck!

 

[Wiregrassguy]

Some shots before and current

Nice work! Are you going to Parkerize it? Here's my Brazilian that was Parked before I got it:

 

[StrawHat]

Kevin, we didn't say that the rods had different threads. There are three different versions and how they are different is not clear to me. But one difference could be the threads are different. The OP has posted that he used early military 1917 parts in a Brazilian gun. Any of the mushroom shaped rods will have right hand threads. So worrying about the thread direction is immaterial.

Thank you, I thought maybe I had missed something.

Kevin

 

[rct269]

According to a thread chart I have, the 1st Model .44 HE extractor rod stem has the following dimensions:


Diameter: .186"
Pitch: 47
Tapping size: .1674"


Now I know there were some changes from the 1st model N frame to the 2nd. But I don't have any reference that shows the dimensions of the 2nd model extractor rod stem.


By the way, those dimension are the same for the M, I, and K frames.

Guy beat me to it, but I have the same "Thread List". It appears to be a Service Department document (as of 5/20/09), and shows all applicable data for every threaded item for the 10 different models (and variations such as the 3rd Model S.S.) in production at the time.

The bottom line is I have shared information from this chart on more than a few occasions, and it has proven to be accurate.

It saved my bacon after I'd managed to booger what I call the cylinder stop screw on a Triple Lock. The folks at Southern Precision said they could make a new one, and after I gave them this chart, they fixed the old one---wizards that they are!

Ralph Tremaine

 

[Militarygunguy]

Yes I cleaned up some beautiful walnut stocks and will give it a zinc park finish once I fit and test everything. I already made up a bunch of handloads for it.

So in absence of finding a tap, does anyone have a recommendation for a smith smith that can fix this for me?