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New mg42 Build, and where to start with it

Posted: Tue Jan 19, 2016 7:25 pm
by along
Hello guys,

so I have finally gotten time to post my mg42 parts kit and simple (yet complicated) question of where to start.

I currently have the following:

apex mg42 parts kit

new 8mm mg42 barrel (from apex)

apex semi-auto bolt

used barrel extension (the original that came with the kit had such a short amount of barrel that it was not enough to grip and take off, I still have it , it is next to the other I bought in the pictures)

brp semi-auto grip stick

brp semi-auto conversion kit

80% mg42 blank from coldsteel solutions

ratchet plate from coldsteel solutions

So as to what I have started to do (which is not a lot):

I have started dremeling out the old front barrel bushing in the front of the barrel shroud. (thats it)

Tools I have:
1. drill press
2. 20ton hydraulic press
3. a 90 amp flux core welder I converted to dc electrode negative (since it comes as ac power output)
4. dremel
5. I access to a mill
6. Dremel SawMax
7. drill pits, dremel bits, files, hacksaw

So with all of that listed, where should I start?

I have been reading various builds and posts trying to answer my questions, however some direct help from the experts here I feel will help.

Thank you for any help

Re: New mg42 Build, and where to start with it

Posted: Tue Jan 19, 2016 8:35 pm
by JBaum
You would need to enlarge the hole in the barrel stub to use a tool called an "easy out", and maybe carefully cut the shoulder at the peen, but that will let you get the stub out of the barrel extension. I'd avoid heating with a torch unless absolutely necessary.

Re: New mg42 Build, and where to start with it

Posted: Tue Jan 19, 2016 11:48 pm
by along
that is a good idea, I actually bought a spare barrel extension. I tried cutting the barrel stub off at the collar with a hacksaw, it didn't work and ended up putting a small nick in the extension. So I just bought one for $30 with no barrel stub in it ready to go.

Re: New mg42 Build, and where to start with it

Posted: Tue Jan 19, 2016 11:49 pm
by along
I read on some post here how the extension shouldn't reach above 400 degrees, is that true?

Re: New mg42 Build, and where to start with it

Posted: Wed Jan 20, 2016 8:42 am
by JBaum
That is most likely someone's opinion, which could be knowledgeable (or not). I don't guess about things I don't know. :)

Re: New mg42 Build, and where to start with it

Posted: Wed Jan 20, 2016 12:31 pm
by along
I see :D , well with my spare barrel extension I think I'm ok as far as that goes. Should I continue to dremel out the front barrel bushing? I'm using a sanding bit so I don't accidentally cut into the actual shroud.

Once the old barrel bushing is out, is it swaged in, welded in, or both?

Re: New mg42 Build, and where to start with it

Posted: Wed Jan 20, 2016 3:18 pm
by JBaum
along wrote:Should I continue to dremel out the front barrel bushing?
If you want to use the barrel extension, don't you need to get the remains of the barrel out? You get to decide the best way to do that. Sanding the barrel piece to where the flange is about gone without damaging the extension, then using an easy out would be what I would do.

Re: New mg42 Build, and where to start with it

Posted: Wed Jan 20, 2016 3:25 pm
by along
I'm sorry if I got the terminology wrong.

So by barrel extension I meant the piece the barrel screws into.
I bought a spare barrel extension ready to have the barrel screwed into, which is the link below

http://mg34.com/product/mg-42m-53-barre ... are-parts/

By front barrel bushing I meant the threaded piece which goes in the front of the front shroud that screws onto the flashider. I have been dremeling out the old bushing piece in the front shroud so I can pop it out and then put the new one I bought from brp into the shroud. Is this piece welded in, swaged in, or both? Below is the new front barrel bushing I bought from brp.

http://www.brpguns.com/products/MG42--F ... shing.html

Thank you for your help.

Re: New mg42 Build, and where to start with it

Posted: Wed Jan 20, 2016 6:38 pm
by JBaum
1.jpg
You're talking about the front receiver bushing. The barrel bushing goes inside the front receiver bushing.

Most guys weld the receiver bushing in place. It has to be turned the correct direction so that the barrel bushing, which goes inside the front receiver bushing (from the rear) can fit in the correct direction.

Re: New mg42 Build, and where to start with it

Posted: Wed Jan 20, 2016 7:29 pm
by along
ah ok understood, would using my flux core be ok to weld it in? I've been kind of wondering if using flux core for this build will be ok at all. I see how people do use their mig welders, but its typically with small wire (.023 or so). The minimum I can use with my harbor freight 90 amp is .030.

Re: New mg42 Build, and where to start with it

Posted: Tue May 31, 2016 10:01 pm
by along
Hello everyone ,

so I have a question about my front bushing I recently welded. When fitting on the flashider with cone inside it, it comes just short of lining up with the front sight holder slot. My barrel stop to front bushing measurement is 19.46875'' (19 15/32''). From the pictures I hope it is visible that the flashider is very close to coming in alignment with the front sight holder. Should I try getting a different cone, or slightly sanding it down with my beltsander to make it so the cone can go a little more up in the flashider (and consequently) have the flashider come slightly more down. The flashider does align with the front sight holder without the cone inside it. I also checked for flatness and levelness before fully welding (when the front bushing was tac-welded).

thanks for the help everyone,

along

Re: New mg42 Build, and where to start with it

Posted: Wed Jun 01, 2016 9:04 am
by JBaum
I don't know what you're calling a "cone". According to the manuals, the flash hider is screwed on until tight, then backed off until the lever drops into the nearest groove. This is just one of the many basic issues covered in the manuals, including the names of the parts.

Re: New mg42 Build, and where to start with it

Posted: Wed Jun 01, 2016 1:48 pm
by along
Hello Jbaum,

my mistake on my terms (still getting those down). I was referring to the recoil nozzle as my cone.

thanks,

along