View Full Version : FM2 Vault Lock Rifle
09-13-2009, 08:44 PM
I finished my M2 tripod this weekend, a picture is below, so I got to start on my Vault Lock rifle.
Tripod, obviously, is above. I got the receiver blank for the rifle cut and squared to size. If any body has a suggestion how to get a better finish on 4140 pre hard I'm all ears. The slowest speed my Millrite has is 250 rpm and I used a 2" fly cutter with carbide inserts.
I also bored if for the breech block, which is round in this design. It's next to the receiver in the pic below.
I chucked it up in the four jaw and bored and threaded for the barrel. Can't really see the threads in the pic below but they are there.
See next post.
09-13-2009, 08:48 PM
I made an aluminum "barrel stub" to act as a wedge and hold in the breech. Also bored it for a punch I made to locate the firing pin in the breech.
Below is with the barrel stub installed.
The receiver, barrel stub and punch.
And all of those put together showing how the punch will be used.
09-13-2009, 10:33 PM
The tripod looks good, and it looks like you are off to a good start on the vaultlock. Keep us posted with progress reports, it is an interesting build. I am casting about for my next build and am considering either a vaultlock or a centerfire Chicopee.
No advise as to a better finish. What you have looks pretty typical to me. I use a flat mill file and then emery cloth backed up with a file to final finish. Usually, even if you start out with a smooth finish, it is pretty beat up by the time you are done with all the operations, and filing and abrasives will be needed to clean it up.
09-14-2009, 12:26 AM
Very good start. To help cut down marks on your parts, plain writing paper between the parts and the work holders will help. Since you did not bore through for the breach block you might want to mill the flat on the front of the block before any more machining on the receiver. Hold breach block with the barrel stub and set the receiver in your vice. The breach block flat can now be milled at the correct angle.
09-14-2009, 08:17 AM
Bob, I bored the breech block hole on my mill with the head set over at 4 degrees. I left it that way and had planned on milling the flat before re-tramming. Won't that give me the correct angle?
JC, draw filing to remove the large imperfections and then emory cloth is what I had in mind as well.
09-14-2009, 09:57 AM
Your plan will work also. There are many ways to accomplish the same thing, was just suggesting what I thought of as a easy way. The flat and the Mann-Neidner firing pin plate must be parallel with the breach or you will have to index mark each case. The barrel stub with the center punch is the same way that I do to get the start for the firing pin hole. It also helps with the milling for the slot for the trigger guard housing.
09-14-2009, 11:25 PM
So I cut the flat on the front of the breech block tonight and the bevel at the top of the block. Right now I have the bevel (that's the part above the 3 degree angle) at 10 degrees and extending down the block .265".
My question is, in looking at the drawings I need this extra bevel to give the extractor room to move and provide adequate extraction. Any suggestions as to how to shape this bevel? I don't want it to run into the firing pin retainer hole which will be .375" from the top of the breech block.
I think I'll have to increase the angle, but to what?
09-14-2009, 11:42 PM
Never mind, I found more discussion in the text. I'll go no further on this until I get to the extractor.
09-15-2009, 08:58 PM
Re: Exterior finish---Got access to a Shaper? It will put almost a mirror finish on the entire block, removing all the tooling marks.
09-15-2009, 11:40 PM
No shaper, could probably put it on the surface grinder at work.
09-22-2009, 11:00 PM
Got the receiver and breech block complete to the point that I can move on to the trigger assembly.
09-22-2009, 11:26 PM
I used flat plate and welded my trigger guard assembles then machined inside and outside. The first ones were welded using 3/32 7018. The last ones used a mig welder. If you try weld the trigger housing machine it. This way the Guards are not in your way when drilling and machining. Weld the guard and lever on last. I felt it was much easier than what was described.
09-23-2009, 08:27 AM
Thanks Bob, my welding skills leave a lot to be desired. I'll take a look at the book again and decide. I'd agree it would be a lot easier if the trigger guard wasn't in the way.
Didn't I read that you use another "trigger guard" kind of thing in the front to open the action? More a finger loop really, instead of the lever at the rear of the guard? Do you have any pictures? I was thinking that would be better than the lever.
09-23-2009, 09:46 PM
For the trigger guard assemble I used 3/16x1¼ angle about 6 inches long. Set up and mill one leg off to .250 high measured from inside of angle. Place a .250 thick spacer material on the cut angle iron. A few ¼ inch lathe bits work well. Use a piece of 3/16 x 1 x 6 to make the other side of the assemble. I use about 1/32 gap between the inside edge of the cut leg and the flat plate to get weld penetration . Clamp securely to a large flat piece of steel or welding table. Weld the two together. Let cool while clamped. You now have a flat surface to machine from the unwelded part of the angle iron. I used a piece of 3/16 material slid inside to hold down the trigger assemble to the mill table and then milled the weld and all of the side smooth. Turn over and milled the angle iron side to dimension. Make or find a spacer for the inside put inside and set your part in mill vice bottom side up. Mill to square and clean any weld left. Turn the part in the vice and mill the inside to dimension, mill the top to the .875 dimension. You should now have a part that looks like one piece of steel. I drilled all holes and did the machining before I welded on the trigger guard.
Trigger guard and finger loop was made from 1/8 x ½ flat stock formed in two pieces then welded together and to the trigger guard assemble. I did not use their trigger spring idea. I used round spring stock formed in a U and secured by a flat plate inside the trigger assemble.
Can’t get photo bucket to load my pictures, so hope this explanation is ok.
10-26-2009, 08:00 PM
Scrap held together to show weld area.
Weld corner and gap.
10-26-2009, 08:03 PM
Action with buttstock rod and forestock rod.
10-26-2009, 08:10 PM
Very nice. I've been out of town and haven't had a chance to work on it any more. I was thinking this week but my sons computer needs work tonight.
Tomorrow and Wednesday dinner with colleagues from work. Maybe Thursday!? Friday night high school football.
Maybe Saturday for a little while!?