Can the SA-MG42 be built like the XMG 34 ?

[TANKER]

Is it feasible to build an MG42 so that it would function in the same manner as the XMG 34 and be able to use the complete AR15 lower as the FCG ? Could the bolt be adapted to work with a FA M16 lower ? All NFA rules apply of course.

[Cpt_Kirks]

Super Shrike!

5.56mm is for little girls. Give me an 8mm belt-fed upper!

[robertmcw]

BRP makes the XMG34 in 8mm, not 223. They take an MG34 and modify it to accept an M16 lower instead of the MG34 gripstick. The upper is also adapted to an AR15 lower for semi fire. The real question is can an AR15 or M16 lower be fitted to the MG42 and operate the modified MG42 bolt. I believe one could, however, the geometry of the fire control parts would have to be changed and the rearward portion of the bolt extension would have to be filled in to trip the modified sear for the M16 lower. I was also wondering if the MG42 gripstick could be modded to accept a registered drop in autosear, using a modified M16 hammer and then possibly creating a new flapper on the sear.

[Cpt_Kirks]

The 5.56mm I was refering to was the Shrike, not the XM.

If an MG42 upper was constructed, it would probably require a milled rear receiver welded to the stamped front. The MG42 TNW is working on is a good example.

It would be a lot of work and experimentation, but would be cool.

[TANKER]

That's sort of what I'm talking about. If BRP can make an " XMG 34 Upper " that uses an AR15/registered M16 lower for the FCG, couldn't we also make an "MG42 Upper" in 8mm or 308, that would use the AR15 lower. Not talking .223 here.....but just like the XMG, only using an MG42 upper instead. Could the MG42 bolt be altered to pass over the AR15/M16 lower and function? ....convenient if you happen to have a FA M-16. Or could you just use the AR15/ registered M16 lower instead of the MG-42 gripstick......with a MG42 bolt.... properly modified to work with the AR15 lower...just like the XMG34? BTW Cpt. Kirks: 07 status achieved today.

[oprod]

I was thinking of going this route as well, and in the course of doing so decided it was best to completely build the semi auto with all approved parts and mods, then get it running reliably and then start looking at the options of an hk sear and gripstick. The problem that has to be overcome is not the fitting of the parts together but rather the modifications performed on the bolt suggest there may be an increased chance of bolt bounce during full auto fire. The mg34 bolt actually turns and locks into groves... kinda like a ar bolt... I think therefore it is a better choice.

[robertmcw]

oprod im not a gunsmith, but theoretically wouldnt the bolt roller locking into place be about the same as the twist action of an ar or 34 bolt, especially with an anti bounce setup in the 42 bolt? then it would just be a timing issue because this gun was designed to run at 1200 plus rpm and in fa mode with a sear it should run at about half that rate?

[TOM R]

I think it would work and look good with beachbums shorty carbine sa42 and would satisfy some of my safety concerns about holdin a 42 near the ejection port

[Cpt_Kirks]

WOW!

Great minds DO think alike!

I was thinking a shorty upper would be best, too. A lot lighter if you wanted to fire it standing up.

[gunslingerdoc]

I came up with an mg-42 upper hand drawing, but it required basically removing the whole grip stick portion of the receiver from the lower edge of the rails down and then welding in a milled replacement that would allow for the AR to be attached and sit high enough. With all the Fal SA stuff and 2-piece FP Ive just never got around to making one. Perhaps a new project is in order.....

[kmw]

I think it would work and look good with beachbums shorty carbine sa42 and would satisfy some of my safety concerns about holdin a 42 near the ejection port

Ejection port. Hmm, that could be the issue. Where would the ejection port be? I'm just not visualizing this one....think I'll take my AR and look at the SA42 receiver....

And the anti-good Captain said:

Super Shrike!

5.56mm is for little girls. Give me an 8mm belt-fed upper!

Shrike? Naw, one of us has more chance of building an AR-42 than a Shrike actually being delivered.

[Cpt_Kirks]

Personally, I want a LM-7.

.22lr is nice and cheap. And I can fire it at indoor ranges.

"AR-42"? I like that!

[aftershock2222]

About four years ago,there was an outfit on the internet that was going to market a semi mg42 that used an ar15 lower.There was a picture of it on their site.I think they were located in Oregon or maybe Washington state.Is anyone familiar with it?

[TOM R]

kmw the spent brass from the 42 upper would eject through the mag well in the ar lower

[041x]

If one were to build a xmg on a ar-15 lower would it have to be an approved design? The way I see it, its like putting a 50 cal or 22lr upper on my ar-15 lower.

[panaceabeachbum]

seems to me you would have to chop up the ar lower as the bolt and recoil spring of the 42 cant fit thru the stock attachment ring, if you want the ar geometry here is what I would do, works well on mine. Snaps right on the 42 semi and runs like a champ.

[panaceabeachbum]

and if you like the original 42 grips

[PvtJoker]

Hi, all. Nice to meet everyone here. I've gotten "the bug" too, and recently picked up a SOG M53 kit and one of the IMA 3-cut receivers. I've been wading through the posts here, and may indeed go with the semi route, but I have been kicking around another idea I'd like to run by you and get your opinions on.

The BRP Stemple Thompson caught my eye, and the logic behind it seems like it might be adaptable to house the Stemple 76/45 receiver tube (with the original FCG and mag well removed, but the receiver itself otherwise unmodified) used to house the recoil spring and a modified bolt that would ride in the end of the tube but still use the feed mechanism and front part of the rails. You would have to modify the cocking handle bar and trigger group to work with the original holes in the Stemple tube, but it might work and since it would be a takedown kit for an already legally registered transferable gun, most of the semi-auto mods would not be needed. Of course, it would have to be prototyped by a licensed manufactuer and sent in for the NFA tech branch to OK it, but in the end, you would have a functional full-auto MG42 replica at a fraction of the cost of an original, with a registered receiver tube that might be also useable in one of BRP's Thompson kits as well. Kind of a functional two-fer (but obviously not at the same time).

What do you guys think? Would it be worth the time and money to get the prototype built and approved? Think there would be a market for a kit with the modified parts for those with registered guns, or for transferable guns with the kits?

[drooling idiot]

anythings possible but i don't see that working.

[PvtJoker]

anythings possible but i don't see that working.

Oh well, just a thought. I guess I'd be better off with the SA version anyway, as it seems to be a proven concept from what I've been reading around here. Plus, with the conversion parts already available from the folks around here the machine work would not be nearly as intense as trying to start from scratch with my idea. Plus the LAST thing I want to do is break the laws about this project. Best not to go tap-dancing in the minefields.

Thanks, and I hope to be around here a while. What is the average length of time most people put into one of these SA versions, if using the conversion parts from the members?