Third Party Press

Semi auto MP44 build

good point

What ever do not send them a request letter, I have seen so many projects get rejected. because someone just had to have a letter and ended up screwing the rest. this has happen time after time

When well enough was good enough, let them concentrate on bump stocks.

I believe this thread has demonstrated that if you follow logic and common sense, you are good to go

its not like there is aft agent at every range or website ( but they want you to think they are)

when was the last time or anytime you heard of someone getting arrested for not complying with 922 regulations???

Good point Jack but there are guys wanting to pay someone to do their build. We both know that is not the same as one guy doing one gun for himself not for sale.
Pete
 
Hrmmm I just got offered a saw cut kit... what to do what to do...

Personally, as much as I would love a semi Mp44 I:

1. Don’t possess the skill to make it myself and
2. Have wayyy too much to lose dealing with any gray area.

Gunna have to let it go I suppose, simple possession of a saw cut is sketchy at best.
 
Do you have any welding experience? I was able to do it myself legally with a little practice as long as the receiver pieces are good and you make a good jig. It also helps if you have any extra receiver pieces to practice on. I was even able to match the original finish with some trial and error.

As stated already, beautiful work. I just finished making a friends MP43 into a working BFONG and it needed lots of help with it's terrible weld job.
 
Hrmmm I just got offered a saw cut kit... what to do what to do...

Personally, as much as I would love a semi Mp44 I:

1. Don’t possess the skill to make it myself and
2. Have wayyy too much to lose dealing with any gray area.

Gunna have to let it go I suppose, simple possession of a saw cut is sketchy at best.

it would depend on when it was cut, if a historic cut then its legal to own as this was historically allowed, it also depends on where its cut

what are they offering for the kit?? you could buy the kit and separate one of the parts, have your cousin store it till you run into someone willing to assist you think ahead
 
I say we just get in touch with tech branch and get a ruling that a kit built like a PTR with modifications x, y, and z is an accepted semi build. Get an answer and put this to bed.
 
I'm a big fan of don't poke the bear. If there are precedents set in law you don't write the judge who made the ruling to confirm that there was a precedent set. You look at the record, in this case the example of an existing approved item, and you refer to it or in this case replicate it.
 
I say we just get in touch with tech branch and get a ruling that a kit built like a PTR with modifications x, y, and z is an accepted semi build. Get an answer and put this to bed.

A good thought but a really bad idea. After all that has been said about the PTR on this board we don't want to poke the bear.

 
Not to be smart but this thread is a study in over complication. AK guys have been rebuilding semis from full auto kits for years, many times using original receiver prices.....and the results are a perfectly legal rifle. This is an EASY thing. Don't over think it and whatever you do, DO NOT go poking around the ATF!!!!
 
When I installed a carrier/op rod in mine that was cut for the full auto trip, somebody questioned the legality of it. It's no different than rebuilding an AK parts kit and using the original full auto carrier (which everyone does) and its perfectly legal. To build an MP44 from a kit, all you have to do to be fine and dandy is:

1. Fill in with weld the slot in the receiver that was cut for the full auto trip.

2. Remove the full auto trip parts from the lower.

3. Weld over the holes in the lower where the pin were for the full auto bits.

Done and done. This is NOT V2 rocket manufacturing we're talking about here. It's rebuilding a select fire rifle as a semi auto only and making it so that you cannot "readily" (as in will need machine work) install the parts to make it select fire or full auto. It's simple common sense and ANYONE who has rebuilt rifles from kits as anything more than a hobby will tell you this. The fact is, ANY of the rebuilt kits or even new manufactured semi auto only military rifles that were originally intended to be select fire can be EASILY converted with a little knowledge and some tools. The ATF knows this. Anyone with minimal mechanical aptitude knows this. Anyone who has ever owned an HK91/93/94 REALLY knows this. All you have to do is build it so that it cannot be "readily" converted. What that means is that you cannot simply remove parts and call it a day. It has to be done in such a way that you will need to do machine work. Period. End of story.
 
... To build an MP44 from a kit, all you have to do to be fine and dandy is:

1. Fill in with weld the slot in the receiver that was cut for the full auto trip.

2. Remove the full auto trip parts from the lower.

3. Weld over the holes in the lower where the pin were for the full auto bits.

Done and done.


... All you have to do is build it so that it cannot be "readily" converted. What that means is that you cannot simply remove parts and call it a day. It has to be done in such a way that you will need to do machine work. Period. End of story.

Fundamentally I agree, but unless that’s written and signed off on by the FED that’s just like... your opinion man. In all seriousness it makes sense, that’s why I am skeptical.
 
Like user "mostpeople", I went through the same thought process when rewelding an MG42 and an MP44. I asked, but all I received here was fluff, or the advice to check on Weaponsguild or Weaponeer. Nobody would tell me explicitly what needs to be done to build a legal semi-auto from a parts kit. Who knows, maybe I wasn't a full fledged member of the local builders elite or didn't know the secret hand shake. I signed up on Weaponsguild and immediately regretted it. More fluff, and slow to load. Builders getting lost in minute details instead of providing a road map. Weaponeer wasn't quite that bad, but also slow to load. Luckily I found out that BRP had an ATF approved MG42 semi-auto conversion, was selling the conversion parts needed and also offered downloadable blueprints, including their ATF letter. As good as it gets.

The blueprints were mostly useless if you used other receiver flats than BRP's. As an example, measurements for holes and cutouts were relative to the front or rear of their receiver halves, not relative to the camming piece cutouts. My receiver flats were longer on both ends, so none of the measurements were of any use. There were measurements relative to top and bottom of the receiver. With BRP's receivers known to be undersized, these measurements were also useless for other receivers, let alone the fact that measurements were relative to rounded instead of plane surfaces, kicking the door wide open for all the mistakes you can make using a curved surface as a reference. Overall one big headache.

When I was almost ready to give up and unload this entire hairball on Gunporker, I sat down one more time and mulled over the operational concept of an MG42 and how parts have to interact for it to work. I started with the center line (because barrel, bolt and rails need to be lined up to work properly), measured every component and marked up the BRP blueprints with new dimensions relative to the center line. A butt stock locking piece with rivets and a bit of torch cut receiver attached to it helped me determine how much I had to cut off the rear end of my flats. From then on work progressed steadily. I also found out why some builders needed to extend the charging handle bar to keep it from popping out of the receiver. It was another byproduct of wrong drawing dimensions. The original MG42 bar never popped out, so why should a semi-auto bar pop out? These builders had cut the slot too long and too wide, almost 1/4" off. I milled as little as necessary and then hand filed for final fitting. The less I relied on other builders' dimensions and the more I used common sense, the better all parts fit together. In addition to BRP's design, I added a couple more obstacles to prevent the semi-auto from being converted to F/A without investing a frustrating amount of work.

The MP44 was a little more straight forward as I had a PTR44 as a template. The differences have been discussed here sufficiently so that I don't need to regurgitate. The only extra thing I recommend is instead of welding the auto sear slot shut, weld a blocking piece of hardened steel into the auto sear slot so it interferes with the auto sear hook on the charging piece. Then mill the auto sear hook off the charging piece so it clears the blocking piece. This way there's no easy conversion consisting of using an original WW2 fire control group and charging piece. It requires partial destruction of the rear receiver to get the hardened blocking piece out. For obvious reasons, the U-shaped denial inserts found in the back of the PTR receiver cannot be used in the MP44 build. That's why the blocking piece in the auto sear slot is so critical. Think about it. If you don't see the reason, put an MP44 bolt and charging piece next to their PTR44 counterparts and it will be very obvious
 
oh boy here we go

someone is going to ruin this for everyone, then walk away leaving the rest of to pay the piper

I have seen this a dozen times in the past 30 years

"BUT I JUST GOT TO KNOW"

lets see the ak build info was not enough, the Thompson build info is not enough, the HK series of rifles is not enough, the MG 34/42 builds are not enough, all the conversions going on at weaponsguild are not enough.

someone wants a useless piece of paper, that in it self can be revoked at any time, let's think atkin's accelerator, sig brace, etc

anyone want to add on to the list of stuff that the ATF approved by letter then revoked

ask Pete if those denials in the PTR-44's are that restrictive, if i recall most PTR-44 members had to substitute the original parts for wartime full auto parts, just to make there rifles function. If a request goes in to the ATF on whats required , you PTR folks may have to modify you rifles even more because ????????????????? the ATF has retroactively outlawed approved weapons designs in the past. forget future import approval

think bumpstocks
 
agreed, but

Like user "mostpeople", I went through the same thought process when rewelding an MG42 and an MP44. I asked, but all I received here was fluff, or the advice to check on Weaponsguild or Weaponeer. Nobody would tell me explicitly what needs to be done to build a legal semi-auto from a parts kit. Who knows, maybe I wasn't a full fledged member of the local builders elite or didn't know the secret hand shake. I signed up on Weaponsguild and immediately regretted it. More fluff, and slow to load. Builders getting lost in minute details instead of providing a road map. Weaponeer wasn't quite that bad, but also slow to load. Luckily I found out that BRP had an ATF approved MG42 semi-auto conversion, was selling the conversion parts needed and also offered downloadable blueprints, including their ATF letter. As good as it gets.

The blueprints were mostly useless if you used other receiver flats than BRP's. As an example, measurements for holes and cutouts were relative to the front or rear of their receiver halves, not relative to the camming piece cutouts. My receiver flats were longer on both ends, so none of the measurements were of any use. There were measurements relative to top and bottom of the receiver. With BRP's receivers known to be undersized, these measurements were also useless for other receivers, let alone the fact that measurements were relative to rounded instead of plane surfaces, kicking the door wide open for all the mistakes you can make using a curved surface as a reference. Overall one big headache.

When I was almost ready to give up and unload this entire hairball on Gunporker, I sat down one more time and mulled over the operational concept of an MG42 and how parts have to interact for it to work. I started with the center line (because barrel, bolt and rails need to be lined up to work properly), measured every component and marked up the BRP blueprints with new dimensions relative to the center line. A butt stock locking piece with rivets and a bit of torch cut receiver attached to it helped me determine how much I had to cut off the rear end of my flats. From then on work progressed steadily. I also found out why some builders needed to extend the charging handle bar to keep it from popping out of the receiver. It was another byproduct of wrong drawing dimensions. The original MG42 bar never popped out, so why should a semi-auto bar pop out? These builders had cut the slot too long and too wide, almost 1/4" off. I milled as little as necessary and then hand filed for final fitting. The less I relied on other builders' dimensions and the more I used common sense, the better all parts fit together. In addition to BRP's design, I added a couple more obstacles to prevent the semi-auto from being converted to F/A without investing a frustrating amount of work.

The MP44 was a little more straight forward as I had a PTR44 as a template. The differences have been discussed here sufficiently so that I don't need to regurgitate. The only extra thing I recommend is instead of welding the auto sear slot shut, weld a blocking piece of hardened steel into the auto sear slot so it interferes with the auto sear hook on the charging piece. Then mill the auto sear hook off the charging piece so it clears the blocking piece. This way there's no easy conversion consisting of using an original WW2 fire control group and charging piece. It requires partial destruction of the rear receiver to get the hardened blocking piece out. For obvious reasons, the U-shaped denial inserts found in the back of the PTR receiver cannot be used in the MP44 build. That's why the blocking piece in the auto sear slot is so critical. Think about it. If you don't see the reason, put an MP44 bolt and charging piece next to their PTR44 counterparts and it will be very obvious

Thinking I posted before something along the lines that individuals doing their own rifles can do whatever they feel, after research, are enough mods. to build a rifle that will likely not cause them trouble. Thing is that some guys have the $$$ for a parts set but not the skills/tooling to build so they seek a builder, most likely should be a 07/C2 manufacturer, who really should have some sort of fed. letter so HE does not get himself in trouble if something stupid happened with a rifle he's required to put his info. on. Saying "I thought this would be ok cause it's like a similar gun" might not cut it then.
All the best to guys doing their own for themselves! Too bad we have to be concerned with this stuff.
Pete
 
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Thinking I posted before something along the lines that individuals doing their own rifles can do whatever they feel, after research, are enough mods. to build a rifle that will likely not cause them trouble. Thing is that some guys have the $$$ for a parts set but not the skills/tooling to build so they seek a builder, most likely should be a 07/C2 manufacturer, who really should have some sort of fed. letter so HE does not get himself in trouble if something stupid happened with a rifle he's required to put his info. on. Saying "I thought this would be ok cause it's like a similar gun" might not cut it then.
All the best to guys doing their own for themselves! Too bad we have to be concerned with this stuff.
Pete

Yes - my 07 who has retired now said, please don't recommend me for this stuff - only for you (meaning me) - for this exact reason.

It only takes one muppet -
 
Haven’t seen one this complete for a while. Another member may be able to pinpoint where this came from, as I seem to recall a thread about a saw cut kit with only one cut to the receiver, before the 3 cut atf requirement came about. Steep price but opportunity for a nice semi build.

https://www.gunbroker.com/item/745452993
 
Haven’t seen one this complete for a while. Another member may be able to pinpoint where this came from, as I seem to recall a thread about a saw cut kit with only one cut to the receiver, before the 3 cut atf requirement came about. Steep price but opportunity for a nice semi build.

https://www.gunbroker.com/item/745452993

I would be very careful with this one. Since it has not been deactivated even loosely in accordance with current ATF guidelines, it could be argued that this is technically still an NFA item. Was a single saw cut ever considered deactivation from a legal standpoint? The seller looks OK but in a different scenario I would suspect this to be an undercover sting.
 
Most of what we see as "atf demil standards" are for purposes of import. The ATF guide actually says as much on it...

https://www.atf.gov/firearms/machinegun-destruction

it is generally unlawful to import a machinegun into the United States for unrestricted sale. However, machineguns that are properly destroyed may be imported. Subsequent pages in this section will provide importers with several illustrations on ATF destruction procedures.


If someone can source me to an ATF link that deals specifically with domestically cut guns, I'm willing to have the debate. Until then, I see a ruling on the book for cutting guns that are to be imported. Its ultimately whatever you are comfortable with, and feel free to send the ATF asking for more, but I don't add words into laws or rulings that aren't there.
 

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