How to build a dummy without damaging reciever??

[ScottD]

Ive come to the conclusion that I just cant afford the receiver welding for a semi right now. What Id like to do is mock it up and hang it on the wall as a dummy gun. Now, my receiver has about 1/8 to 1/4" gap between parts, so I was thinking about doint this:

Dummy the receiver up and tack weld some scrap metal to hold it all in place. Then I could go back and fill in the rest of the areas with Bondo or Fiberglass and paint to match. Im a very amature welder and only have a cheap MIG welder, so Im wondering if a few quick tack welds will do any damage?

I know, I know, dummy guns are LAME, but IM tired of looking at it sitting in a pile on the floor!

[Bil]

I don't see how the amount of welding you are talking about will damage the receiver any more than it already is.Any welds you make can be easily cleaned up later.I think I would try to use a flat plate and the holes for the rails.This would also give you some backink for your fill material.The receiver will be sturdier,too.For fill,I would try JB Weld,it is an epoxy type with metal also,it sands out nicely.I have used it to do cosmetic repairs on auto parts.It is strong and looks good,I think it would blend in nice.Just some ideas,it would be better to see it hanging up than in a closet gethering dust.It may also serve as an inspiration to actually get it built for real.Good luck,and have fun! ---bil

[bolex]

You need to weld the FA bolt block in along with making the FA grip not locking in the receiver. This should be done before welding of the receiver pieces.

[FAL_specialist]

Heck, if your going to do all that, you might as well weld it together for real.

The only way to go from novice to expert is practice. Practice on some 14 gauge scrap metal.

When it comes to the real thing, you might want to grind the edges flatter ( within reason ) and cut filler strips rather than try to fill a 1/4" gap with weld.

Larry

[ScottD]

There is no way Im gonna try and weld this thing into a functioning semi gun. As I stated earlier, all I have access to is a nasty cheap MIG welder. TIG welders run 300-400, but a semi welding service will run me 450. Im NOT gonna butcher this gun to save myself 50 bucks. And even if I did, I dont know all the little tricks of welding. IM better off to out source it. Trust me, Im no mecahnical pu$$Y, Ive done two engine swaps on my Camro in the last 3 months, I just know my limitations.

As far as the legality, Ill deal with that when I get a little closer. Ill either install a bolt block or totally close the trigger opening or something. That part Im not worried about.

[mgfun]

I think you must incorporate all of your semi mods to the parts before you touch that receiver with a welder.connecting any of the sections via a strip of metal and welds, no matter how poorly done, may be a problem without the semi mods, 1st.

Aside from holding it together with a couple of tie wraps, I doubt there is a way to dummy up 42 receivers without the semi mods in place. (maybe if you cut out a receiver section to shorten the bolt motion and welded a plugged barrel in?)

I'm no expert, but a mockup of the 42 without semi mods needs to be turned into a lump, just about.

those knowledgeable please chime in now

Regards,
mgfun

[drooling idiot]

definitely use caution about welding , even just tack welding the receiver together.

what do you think of this?
take a 3/4" black iron pipe , insert it into the receiver, drill and tap where the rivets would go then stuff the torch gaps with plastic trash bags to 1) not hold moisture like newspaper would and 2 provide a backing to build the bondo on .

just off the top of my head but it seems cheap, easy ,and hard to convince a jury you were trying to make an MG.

[88comm]

How about using a block of wood, cut the right size, and forced into the inside of the receiver parts? The bolt and rails could not be inserted, there is no way a cartridge could be inserted, much less fired and a barrel could probably still go in place. Paint the whole receiver, wood and all, flat black without any putty. It will look pretty good, but still be parts.

As insurance, you could ask the local law officer (Chief) if he would call it a gun or an ornament. Take the stock and block of wood to show him.

[Bil]

I am holding an Allegheny Arsenal mg42 non-gun i my hands.The complete buffer is installed,spot welded lightly .The FA grip is installed,I just took it out.There are no mods to the mount,nor is there a bolt stop.The torched rails are still there,in pieces.There is also a piece of steel welded inside the receiver,flush with the top.This prevents the bolt from being inserted.It can't get in the back, and there is no place to go if it did.The rails are also in pieces.To convert this into anything,you would have to-cut out the buffer-cut out the big piece of steel.replace the rails.The cast cam piece is also welded on,that would have to be fixed.The barrell door is also spotted shut.It would be a lot of work to convert this.I still think if you do the semi mods to the receiver[it takes about 10 minutes with a dremel,drill,and spot welder] Then bolted it together in the rail locationg,and did your filling,it would be legal.The bolt couldn't be installed-no rails.FA grip wouldn't mount either.It would take too much work to be a gun,you would have to start out where you are now. ---bil

[ScottD]

Im thinking Im gonna install the FA bolt stop and NOT install the rails. I will open up the trigger slot so it wont accept the FA trigger group.

Im starting with the bbl shroud/camming section tonight. I figure this will be fairly easy, with the cam in place it will give me a template to weld by...

[Bil]

I think you are going in the right direction.Like starting any build,but you are just not finishing at this time. ---bil

[ScottD]

I started the welding tonight. Ive tack welded the shroud and the camming section, and the rear of the receiver behind the camming section. I might actually be able to pull this off with a MIG welder. Ill have to go slow and only do small spots at a time, with lots of filler material, but I might actually be able to weld it up myself. Has anybody with only moderate experience put one of these back together with a MIG machine?

[88comm]

All of my '42 is done with a MIG machine. I did it exactly as you are - very small welds (tacks) to hold it assembled. Then check alignment, then tack again. If anything is misaligned, I used an abrasive wheel in a 4" grinder to cut the weld, then bent it into alignment, then tack again. Let it cool between welds and you will get very little distortion. Also with small tacks you can built up areas that are missing metal - kind of like building sandcastles by dribbling wet sand...
Keep the beads short so excessive heat doesn't cause the metal to flow away.

[MGW LLC]

Oi......While doing what you planned will not hurt the gun per say...... I gotta tell ya bro, there are better ways!