Building The Steven's Favorite

[TomG]

I did some work on a rifle for my uncle a while back, a Stevens Favorite 1915 single shot .22 caliber, making a new firing pin for it and fitting a new extractor. After shooting it a few times to make sure the new parts were behaving, I took a liking to the little rifle. It is a great looking, good pointing little rifle and is a joy to shoot. I decided it would make a fun project to build one from scratch so I proceeded to completely disassemble the rifle and sketch up all of the parts, including the stock. After that I decided to make a 3D CAD model of it to check my work and make sure all of the parts fit and functioned properly. I'm just about finished with the model with just a few parts left to model and some timing issues to work out in the action.

I am not making an exact copy of the original gun, so some of the parts won't interchange with an original. Some of the parts will be redesigned for ease of machining, especially in the case of the receiver which was originally cast. Most of the parts on the original gun were quite crude and appear to be hand fitted so making them interchangeable would be quite a challenge.

My plans are to make the receiver out of case hardened low carbon steel for ease of machining, the breech block and other internal parts out of O1, and the barrel out of 4140 if I decide to make it. It's kind of hard to justify the work with all of the inexpensive barrel blanks that are available.

According to the following statement from the ATF website (kindly pointed out to me by another member) it is legal for me to build a non NFA firearm, which this most definitely is with its 30" barrel and single shot capability, as long as it is not built with the intent to sell and the maker is not prohibited from possessing firearms, which I am not. There are also zero imported parts used in this rifle as I intend to build them all myself.

Q: Does the GCA prohibit anyone from making a handgun, shotgun or rifle? With certain exceptions a firearm may be made by a non-licensee provided it is not for sale and the maker is not prohibited from possessing firearms. However, a person is prohibited from assembling a non-sporting semi-automatic rifle or non-sporting shotgun from imported parts. In addition, the making of an NFA firearm requires a tax payment and approval by ATF. An application to make a machine gun will not be approved unless documentation is submitted showing that the firearm is being made for a Federal or State agency.
[18 U.S.C. 922(o) and ®, 26 U.S.C. 5822, 27 CFR 478.39, 479.62 and 479.105]

I have since received a response form the BATF regarding the legality of building my own firearm and they referenced the very same statement, so it's official: I'm good to go.



There is a JPEG of the model below and a link to an eDrawing file:
  Stevens Favorite.easm (Size: 345.35 KB / Downloads: 371) . An eDrawing viewer is required to view the file in 3D and can be downloaded here.

Tom

[TomG]

I think I have most of the issues worked out with the action so I got busy and cranked out some drawings, started on the receiver and actually made some chips today. I'll post pictures as I go and make this thread sort of a build blog. And here..we.....go...

I started with a 1 x 4 piece of mild steel bar stock, milled it to the proper thickness with a fly cutter and squared up the sides.

The next task was to do a rough layout to locate all of the arc centers and holes.

I plan on cutting all of the smaller radii with end mills and the boring head. It will need to go on the rotary table later to cut rounded surfaces on the contours.

Boring the hole for the barrel using the boring head.

The two 45 degree flats were cut with a 90 degree end mill.

The toughest part so far was milling this deep slot with a long 5/16 end mill.

[TomG]

I needed a cutter to mill the 1.5" radius on the contours of the receiver. Since nothing like that is available commercially that I know of, I had to make it myself. I first modeled it up in SolidWorks to work out all of the clearances so I would have a better shot at getting them right the first time. I used a piece of 1" diameter O1 and turned one end down to .875 to match the largest collet on my mill. All of the milling was done in a dividing head, with a tailstock for support, using end mills and a boring head. The faces of the four flutes were milled first, then the blank was rotated 5 degrees for the primary clearance and the 1.5" radius was cut using the boring head. Next the blank was rotated 32 degrees and the secondary clearance was cut in the same fashion.

When the cutter was finished I tried it out on a piece of scrap aluminum and it seems to work pretty well. It hammers just a bit due to the lack of back rake but it should be fine for this one time use.

[TomG]

I had to go back to work today to support my expensive hobbies so I only managed to get a couple of hours in on the Stevens.

I had an old piece of jig and fixture plate laying around so I decided to use it to make a sub-plate to hold the receiver. A sub-plate makes it much easier to work on a complex part because there are no clamps to work around. In addition, it allowed me to spot holes at the center of all the radii making changes in set-up much quicker. After making the sub-plate I had time to saw out the rest of the receiver and make one cut on the top, a 3" radius blended into a 16º angled straight cut. It's been a while since I've used the rotary table and it was fun to dust it off for a change.

Tomorrow I'll harden the form tool so I can use it on these surfaces before breaking the set-up.

Tonight wasn't as productive as I'd hoped. I hardened the cutter and it came out glass hard with no cracks but I think I got carried away tempering and went too far. When I tried it out on the receiver, it wouldn't hold an edge. I'll need to heat treat it again before moving on to the next step. I'll leave it full hard next time and just be careful not to push it too hard and chip it. At least the receiver is starting to take shape.

The second time worked like a charm. I re-heat treated the cutter and left it full hard. That would not have been an option if it was smaller because it likely would have broken during use. Then I sharpened the face of the cutting edge with a die grinder and went to work. The cutter had to be fed very slowly because of the amount of cutting edge in contact with the work, but it cut cleanly and held an edge. The next task is to mill out the tangs where the stock attaches and then finish hollowing out the inside.

I had to do some house painting today so it cut into my shop time a bit, but I still managed to get the upper and lower tangs roughed out. With all of the material that needed to be removed, I broke out a 3/4" roughing end mill to speed up the task. I forgot how much fun they can be. At one point I was taking a 5/8" deep cut at a 3/4" per minute feed rate. The next task is to finish mill the inside of the tangs, round the ends and drill the holes in them.

Lots of clamps are mandatory when cutting steel and a piece of paper between the part and the table will help keep it from moving.

Notice the clamp and spacer to support the long flimsy tang.

A 3/4" roughing mill, 5/8" deep, 3/4" per minute, no coolant. I love these cutters!

[RobWilson]

Very very interesting project Tom .


Looking forward to the next instalment


Rob


PS ,,,, is that an Ellis dividing head your using ?

[TomG]

(06-19-2012, 01:16 AM)RobWilson Wrote: Very very interesting project Tom .


Looking forward to the next instalment


Rob


PS ,,,, is that an Ellis dividing head your using ?

Thanks Rob.

It is an Ellis dividing head. I wouldn't own anything but an Ellis.

Tom

[TomG]

Machining these tangs required a lot of different set-ups due to the fact they are not parallel to each other or perpendicular to the axis of the receiver, plus the various holes in each one and the full radius on the ends. The most creative set-up was the one required to mill the full radii on the ends of the tangs. I clamped a parallel vertical in the vise and then clamped the side of the tang to it using parallels for spacers. It was an ugly set-up but it got the job done without a crash due to attention to cutter forces and a total lack of climb milling. Do not try this at home. Next comes the part I've been dreading, hollowing out the inside of the receiver. It's going to take a combination of drilling, long end mill milling, slotting and possibly broaching to get it done.

All told it was a pretty productive day. I got all of the internal cutouts roughed out with end mills and it went much better than expected. Some of the extra long end mills still needed to be gripped on the very end, which really cuts down on their rigidity. I've had a lot of experience working with long end mills and was able to get through the whole job without breaking any. Long end mills demand special techniques that can only be learned the hard way and I've broken more than a few learning them. Next on the to-do list is grinding a slotting tool bit and squaring up all of the corners in the pockets.

This was the deepest pocket and it need to be cut from opposite sides to get through.

Power tapping a 5/16-24 thread in the mill.

This was the longest reach. I drilled two holes through to start and then milled it with a 1/2" x 5" end mill which was just barely long enough.

Milling the slot for the hammer.

[DaveH]

Tom,

Beautifully shown - really great and very interesting

DaveH

[TomG]

I made a bar to hold a triangular carbide insert to square the corners out on the pockets. Since there was no clapper built in, I had to limit the feed to .001-.002" at a time to keep from chipping the carbide. It did a good job though, it was just slow going. One down, three to go. I also started filing and polishing the machining marks out.

Tonight's task was to make a slotting tool to square the corners in the trigger and hammer pockets. I made the tool out of O1 the full width of the slots with a 1º lengthwise taper on each side, 10º clearance on each side and 10º end clearance. All that is left to do on the receiver is to file out the rest of the machining marks, polish and color case harden. The hardening will wait until all of the internals are finished and installed in case any "engineering changes" need to be made.

I was working on the honey-do list this weekend so there wasn't much time for the rifle, but I did manage to make a few screws. The following pics show the procedure to make two 8-32UNC slotted, fillister head screws, a typical style used in gunsmithing. They were made two at a time, one on each end of a piece of .25" O1 round stock.

The ends shown faced and center drilled.

A slick way to set the threading tool is to place some paper under the tool and shine the work light on it. That makes it really easy to see the gap between the thread gauge and the tool. Leave the locking screws loose and just slide the gauge back and forth until the tool is lined up.

Checking the pitch diameter of the thread.

Threads are fun to cut on the Hardinge because it has a lever to quickly lift the tool at the end of the cut without disturbing the setting. This makes a relief cut at the end of the thread unnecessary.

Next, the screws were parted off, the heads turned to the finish diameter and faced to length.

A form tool was ground to machine the crown on the heads.

The slots were cut with a .035" slitting saw. A collet block would be a better way to hold such small screws but the right sized collet was lacking in my selection.

[ETC57]

WOW!!
Very cool Tom,

Thanks for posting the build.

Jerry.