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Sterling extractor to ejector conversion?

Posted: Wed Apr 09, 2008 2:28 pm
by JRAnderson
I'm looking to buy a Sterlingworth project that needs forearm iron. I was wondering, As long as I'm making the forearm iron, how hard would it be to make the ejector iron and convert the action as well? I'd take the time to make CAD drawings from existing parts. As long as I'm making one using my Prototrak, I'd probably make a few extras to help offset the cost of drawing, fixturing and programming. Any thoughts on material? I was thinking 8620.

Any info here would be much appreciated.
Thanks

Posted: Wed Apr 09, 2008 6:47 pm
by fox-admin
Forget it. You also need to make modifications to the action that would be cost prohibitive.

time is money

Posted: Wed Apr 09, 2008 7:47 pm
by JRAnderson
fox-admin wrote:Forget it. You also need to make modifications to the action that would be cost prohibitive.
I wouldn't be paying someone else to do this. The only money I would be throwing at this after the initial investment would be for raw materials. And outsourced heat treatment. Not machine time. I thought if they could do it 100 years ago, why couldn't I do it now? All I need is a little information.

Posted: Wed Apr 09, 2008 8:05 pm
by fox-admin
Boy you like challenges. I would buy a ejector gun and use it to make drawings etc. No blue prints exist that I have ever heard of. A patent search would give you a basic drawing of the mechanism.

Posted: Wed Apr 09, 2008 9:09 pm
by Silvers
I concur with Fox Admin. Is it possible? Yes. Is it practical? I wouldn’t do it.

Just some offhand thoughts. You’re not going to make two ejectors from one extractor. If you try to use two extractors to make two ejectors the rim cut in one will likely not match the cuts in the barrels. The extractor stem is shorter than the half stems on ejectors, they’ll have to be lengthened. The fore end attachment lug on Sterlingworths is different than graded guns. That means you'll want to find or borrow a SW ejector iron to copy. The tang at the front of the frame that pushes on the extractor stem will have to be shortened and profiled for the ejector stems. You’ll have to find ejector mainspring followers, and locate and drill holes in the frame for same. In addition to the iron you’ll have to find or make the ejector sears, ejector hammers and related parts.

In net, I would suggest you look for an extractor iron and build the gun with it. They are often found on the internet gun websites or you might try a WTB post here in the Parts section. You are highlighting your ACGG member here so I assume you are in a "for profit business". Even though this might be a labor of love or prototype you might be better served to use your machine tool time for something else. Of course this is just my opinion. Silvers

Posted: Wed Apr 09, 2008 9:58 pm
by bbman3
JR, It is bad at all changing an extractor frame to ejector. Making the complete ejector forend would be the hard part but sounds like you are set up to do it and have the desire! On the frame remove the hammers and punch out the small round plugs in nose of frame by inserting a punch or steel rod in hole main spring goes in. Then you need the spring follower with the split in front that the t shaped piece fits in that works ejectors.you need to shorten the stud that fits in hinge pin ,but that is simple. I do not have my parts list at computer to give correct name for the pieces. I have the two pieces that fit in front of main spring for smallbore gun. Bobby

Posted: Wed Apr 09, 2008 10:00 pm
by bbman3
not bad! correction!

Posted: Thu Apr 10, 2008 12:07 am
by JRAnderson
Silvers wrote: You’re not going to make two ejectors from one extractor. If you try to use two extractors to make two ejectors the rim cut in one will likely not match the cuts in the barrels. The extractor stem is shorter than the half stems on ejectors, they’ll have to be lengthened. Silvers
Silvers
I'm still just kicking tires here. I'm not sure how the extractors are made. Are they made from 4 separate pieces? 2 guide pins, the extractor plate and the push rod? Or are these made with the extractor plate and the push rod as one piece? That would be a lot of metal to move making one from scratch. Do you think it would be possible to split the extractor with a wire EDM only removing around .010" of material. Or is this too much slop between the new ejectors? If this would work, I could TIG weld an extension on the push rod using filler rod that is used in punch & die repair for proper hardness.

bbman3
I haven't seen what's inside of the forearm iron. I'm thinking there isn't much at all involved with the extractor iron. Making one couldn't be that difficult. I suppose seeing the ejector forearm iron out of the wood would be interesting. Can't be too much inside of that little splinter forend. It's interesting that you say that there are plugs that can be knocked out to allow the connectors for the ejector hammers. I thought that this would be a difficult deep hole angled setup.

If anyone has pics of the ejector iron out of the wood, I'd sure appreciate seeing them.

Thanks

Posted: Thu Apr 10, 2008 12:14 am
by JRAnderson
I'm also not sure if the short rib section between the loop and the hook is mounted differently for the two different models. Possibly the longer ejector push rods and swinging hammers need more clearance from the rib than the shorter extractor rods???

Posted: Thu Apr 10, 2008 8:00 am
by eightbore
James, considering the number of very average condition 12 gauge non ejector Sterlingworths out there, I would suggest you expand your horizons to include parts fabrication for multiple conversions to ejector. it sounds like a great little niche business for a custom gunmaker. Step one of such a project would be the procuring of a well preserved ejector Sterlingworth to use as a model. Regardless of how much information you get on an internet chat room, I'm sure Ansley Fox and his successors came up with some small piece of important information that you may miss if you never actually see one of their ejector guns. Even the Fox people came up with a system for ejectors that was much improved early in the history of the company. Even their first effort at ejector design was found to be less than acceptable.

Posted: Thu Apr 10, 2008 8:08 am
by Silvers
(Edited, not enough coffee this morning)

The extractor plate and push rod (stem) are one piece. It looks like a forging; there's no evidence of piecing together. Splitting the stem with ED machining won't work IMO. In 12 gauge the stem is ~.250" diameter and perfectly round. Putting two ejectors together, the stem diameter must be the same as on the extractor. Sure, you can overlay the splits with weld to revert to that diameter but that may lead to warping of the stem. Anything can be made, but sometimes it isn't practical to do so.

The front end of the SW frame does not have anything like "pop out plugs" for quick change from extractor to ejector. The plugs seem to be there so a blind hole didn't have to be counterbored from the back end on one type frame and not the other. Bobby said the plugs can be driven out, rather than drilled. That's new info for me. It probably depends on how tight the interference fit is. You obviously like challenges and I wish you the best with your project. Just for perspective I am associated with a large machine and precision grinding shop nearby my home and can get work done gratis by expert machinists with high tech tooling. I wouldn't do this project. Again let me wish you good luck. Silvers

Posted: Thu Apr 10, 2008 10:40 am
by JRAnderson
I guess I should have bought the dented 16 SW on Gbroker a short while back for reference. Then I'd be asking questions on how to build a barrel set. :D

If I can't justify the time to convert from ext to ejector then I'd need to make or buy the correct iron. How many different kinds were there? Does the 20 ga interchange with the 16ga?

Posted: Thu Apr 10, 2008 9:33 pm
by yelloh564
JR, I believe bb3 is giving you good guidance on the conversion of the receiver. I can help you with the 12 ga ejector iron.I am pretty sure I have all other parts you would need. Most are NOS, never fitted, and whole lot easier than building from scratch. send me a PM and I'll give you some contact info.

Posted: Thu Apr 10, 2008 10:19 pm
by JRAnderson
The project gun I'm looking at is a 16 Gauge. I guess I didn't clarify it earlier in the post. That's why I asked about the compatibility of using a 20ga forend iron. It's my limited understanding that the 20 and 16 actions are the same. Does this mean the forearm iron is the same???

Posted: Fri Apr 11, 2008 7:57 am
by Silvers
The 12 gauge iron is much larger. It will not work on a 16 gauge frame. The 16 and 20 gauge irons are the same basic form, however there may be subtle differences. I have a couple of 16's but have never been too keen on 20's in any gun so I can't compare the two for you. Sorry. Silvers