MPFiveO

Have you tried CMP? They have a store in Ohio.

Seen several sell on GunBroker recently. None of the surplus places are going to have them. Don't know if Indianapolis Ordnance has made any more. I bought one a while back and had it parkerized locally. I haven't fired it yet though.

I'll try to clarify. And I'm not looking for a way to skirt the law or anything like that. I'm looking for precedence. For example. During the amnesty you could register your factory braced AR, let's say a Sig for example, and the requirement to apply maker engravings was waived because Sig made it that way. We understand this point. What I'm looking for is whether or not future transfers will have the disclaimer on the back of the form. The reason I ask is that there are still many that don't have a full understanding of the ATF engraving requirements as well as a host of other made up rules. So, if a guy picked up another identical Sig and filed a Form 1 to SBR it after the amnesty but didn't engrave it, that one would be non compliant. But, with subsequent transfers how is anyone going to be able to tell the difference? It's probably a question for the ATF but if anyone has transferred one it would be interesting to know if they're going to track them differently.

Posted this on another forum and even with a hundred views not a single answer or even a guess has been submitted. Anyone here care to take a shot? So, the amnesty forms were all issued with a note on the back that read "pursuant to ATF Final Rule 2021R-08F" This is an indication that the firearm was registered as a SBR under the amnesty requirements and that it required no additional markings by the maker because it was already a SBR from the manufacturer. That being said, will all subsequent transfers via Form 4 etc. have this notation on the form or is that just a one time thing? Because at some point there will be discussions and disagreements over this issue. It's never really made sense anyway for a maker to add additional markings since manufacturer markings are already more than adequate to identify the firearm listed on the paperwork. The only logical reason to apply markings is if there are none to begin with.

Only if it's a newer one. The Type A and B did not have a sear block and had normal size pins. The current model does have the web of material in the fire control pocket that would have to be milled out to accommodate the DIAS.

The AR-15 has recoil?

In addition to the DIAS you'll need a hammer, trigger, disconnector and selector. You'll first need to check your hammer and trigger pin sizes to make sure they're .154 and not .170 as there are no M16 parts for the .170 size pins. Not exactly sure what you mean by bolt slap. The DIAS functions and behaves exactly like a pinned mil-spec GI auto sear, except that it is also functioning in the semi auto mode where the factory pinned sear rotates forward out of engagement. The 9mm's do sometimes exhibit trigger slap making shooting it a bit uncomfortable on your trigger finger. Make sure you have the correct heavy 9mm buffer. Bolt bounce can be more prevalent in the 9mm blowback, there's absolutely nothing to keep the bolt in battery. Lastly, invest in a pair of stainless steel hammer and trigger pins. They're tougher than the carbon steel pins and less likely to break. Broken fcg pins will quickly trash your receiver.

Mike has a little over a dozen parts sets to build finished guns. My buddy just got one, serial between 130 and 140. So, there are a few left to be made. If I wanted one right now I'd get a loan from the bank, or whatever it took, and call Mike and get put on the list, because when he's done with these there will be no more.

https://liemohnmanufacturing.com/ He's currently recuperating from surgery but should respond to emails.

Well, one has to understand the proper intended use of the C-Mag. They're part of a Light Support Weapon kit. They're meant to be fired prone or supported with a bipod and the support hand tucked under the stock near the shoulder. This works great with the Colt RO750 LMG, Steyr AUG with LMG barrel and a HK 13 with a quick change barrel and 23E style stock. I doesn't really lend itself to a standard M4 Carbine from the shoulder. They're great for blasting long bursts of ammo but awkward to carry around.

I get where he's coming from too. All firearms can be dangerous. Firearms shooting really big cartridges can be really dangerous. A 5.56 round might contain around 26 grains of powder. A 7.62 might contain around 48 grains of powder. A .50 BMG might contain around 230 grains of powder. A 20mm Vulcan can contain up to 600 grains of powder. A mistake can be catastrophic. Comparing bullet weights you have 5.56 at 55-62 grains. 7.62 is 147-180 grains. .50 BMG averages 600-700 grains. A 20mm AP is around 1900 grains. The 20mm rounds require special presses and dies and getting powder and components these days can be tricky due to ever changing demil regulations. Then there's the issue of transporting and finding a place to shoot it. My range is in a valley surrounded by mountains extending into the National Forrest. But it's only 100 yards long. The CMP won't even let me shoot my .50 on their range so a 20mm is definitely out. Like the .50 BMG, the range of the 20mm round is extreme compared to a run of the mill hunting rifle. Getting it there is going to require a bigger vehicle than a Prius. I can throw half a dozen Subguns in the back of my two door Jeep and take a buddy to the range with me. The Anzio breaks down into two of the largest Pelican cases made. Definitely going to need a long bed pickup. And again, this isn't really something to do on a budget. Cutting corners with a large capacity cartridge doesn't seem worth the risk. For the $8K I would consider investing in something with an equal fun factor but more suitable for transport and less liability. I'm not going to say you don't have experience, but how much experience can you have if you don't already own one? I've been driving since 1985. I've been to numerous training sessions on pursuit driving in my 26 year career in law enforcement. I know how to drive. But, I also don't know a damn thing about driving a funny car or top fuel dragster. I know they can have thousands of horsepower and do 300 mph in the blink of an eye. And I know I have no business getting into the cockpit even though I know how to drive. Just something to think about before you drive into the shallow end of the pool.

Anzio has the most affordable 20mm on the market at around $15K. I don't know if I'd put my trust in one for half that price. I remember a guy brought something on a mount to one of our machine gun shoots. I'll try to find the video. No idea who built it. Everyone around it was nervous. Found the video. The "cannon" is fired at the 2:40 mark. Prior to that it's a bunch of commentary from people thinking they're about to be vaporized. https://youtu.be/d7MGdhILZxQ?si=uGGRGfC67AMcomkR

I'd keep it as a spare. Not really worth selling but definitely worth keeping. Another build might just grow out of it.

Links work for me. That's definitely an aftermarket carrier and possibly bolt. Looks very similar to the one that came in my S&W M&P 15. It has a full ramp but the sear trip is cut back. Like you said, an original bolt group isn't hard to find. Overall, a very nice looking SP1. I see the spot behind the magazine release button you mentioned. That can be touched up with some Birchwood Casey Aluminum Black.

A 1977 BCG should be marked with a C on the non ejection port side. It should also be of the SP1 semi auto profile. The bolt should be marked MPC behind the locking lugs. Hope you can share pics soon. I know of a couple of sellers on GB that sell complete SP1 lowers but they replace all the internals with cheap kits and sell the original parts separately for more money. It's just cringe to part out SP1's but it seems to be a thing there. I highly recommend this book for anyone with an interest in the Colt SP1. It's excellent reference material and just plain cool to see the evolution of the rifle. This place is out of stock but I'm sure the books are still available. https://rdgunbooks.com/shop/ols/products/colt-collectors-guide-to-the-colt-ar-15-sp1-sporter-rifle-by-p-cox-and-bruce-kaufman-new

The ones on my grips are staked...

Its an LWRC SMG45 which explains why it has no buffer tube. It looks like it would take standard M16 parts and a GI sear after milling and drilling. There's a hood of some sort that sits on top of the disconnector and I'm not sure what it's purpose is. Parts diagrams and photos of internals are scarce. Does anyone know what the trip for the sear even looks like? Or how it's held in place? Also, after reading up on the dismal performance of the LWRC SMG45 I'm not sure it would be the best choice for a post sample conversion. And, they've been discontinued but they will still work on them. That blocks the path of getting a factory replacement receiver. I have my doubts that they'd service a converted gun for liability reasons. Then there's the fact that it retailed for something like $3000 so I can see why some C2's would be hesitant to work on it. They might get blamed for poor function, trigger slap or parts breakage, which they already do according to a lot of unhappy customers. No wonder it was discontinued. It might be desirable as a parts kit to someone...

There are basically three receivers, if you don't count the Armalite 601. The earliest Colt from the 60's had a partial fence lower. This was the first one to use a captive front pivot pin. Then came the A1 with the full fence around the magazine release button. The A2 further improved the lower by reinforcing the front pivot pin lugs with a radius. It also added a thicker band of material to the rear of the receiver where the buffer tube screws in. Most of the early partial fence lowers were marked AR-15. These were made before the rifle was adopted by the military and designated the M16. The full fence A1 lowers were first used starting somewhere around 67-68 and nothing changed until the A2 reinforcements were introduced around 1982-83. So, all of the M16's made between 68 and 82 used the exact same receiver regardless of the markings. A commercially marked M16 or M16A1 will have the exact same lower as a 603, 604, 613 or 614. Even the US Property marked lowers use the exact same receiver. And, in addition to this there were quite a few A2's that used A1 lower receivers. So, while the lowers had a variety of markings, they only served to identify a particular model or indicator of whether it was for export or commercial use. As for the quality, they are all pretty much identical.

M60 Joe has retired but he did do small pin conversions back in the day. Any converted Colt will be marked either SP1 or A2 Sporter II. Pretty much all the other semi auto models were made after 1986. These will all be slab side lowers with no retained front pin. There are full auto factory AR-15's but they'll have either a full or partial fence. The only one that doesn't have a fence is the Armalite 601. The AR-15 marked guns will usually have a Model designation such as 613, 614, etc. It's hard to establish a hierarchy because certain models are desirable for certain reasons, rarity being the primary reason. The A2 is the lowest in numbers because they came out just a couple of years before the 86 ban. There are lots of 9 million serial number range M16A1's and also lots of Model 604's, 603's, 614's and 613's made through the 70's. And in fewer numbers are the 60's era guns like the partial fence 602's. Lot's of guys place a premium on US Property markings because they are few in numbers and may have been used in an actual conflict once upon a time. If you just want a shooter that's a Colt I'd suggest a M16A1 or a 600 series of the same thing which would be a 603/613.

Since this is a LMG related post, would you mind sharing the rebuild process? I've never messed with hydraulics but I have one of the buffers and I know they have a limited lifespan.

Now you're thinking like Colt!

Well, if you can find pictures or dimensions, or if you can find someone who owns one we'd be miles ahead in getting it done. It's not really a project that anyone would want to do from scratch.

I'm not a Reising expert yet, but I'm working on it. I have an all original 1941 Reising. I've only shot a few hundred rounds through it so far. I'm waiting on my local gunsmith to do a batch of bluing to include my rear plug. Mine still has the one piece plug known for breaking. I also picked up a titanium replacement firing pin and plan to replace the original so it doesn't get broken. Then there's the Wolff spring kit, because all the springs in the gun are 80 years old! I also bought one of the reinforced muzzle brakes because I don't want to damage the original. So, despite the gun looking and shooting perfect, I've planned to swap out all these parts at some point. As for the firing pin, the best observation I've made is that they're probably going to break regardless. I don't know if there's a way around the design. It's been noted that the firing pin shouldn't protrude past a certain point because that is how it will get broken. To understand how this happens we must understand inertia. When the gun fires, the bolt is thrust back. When the empty case hits the ejector there is no longer anything blocking the firing pin from moving forward. If the firing pin is able to move forward and stick before the bolt stops it's rearward travel, then when the bolt moves forward the next round being fed from the magazine will be pushed up the bolt face and crash into the extended stuck firing pin. Supposedly a rebounding firing pin will prevent this. I think that also a positive stop on the retaining pin cut would help. Maybe I can talk my buddy into doing a CAD drawing if we can get the dimensions for the bolt and firing pin. The dimensions would need to include the location of the retaining pin. What needs to happen is for the firing pin to be struck and inertia carry it forward. It only needs to protrude enough to fire the round. The positive stop needs to be where it doesn't cause damage to the retaining pin, yet it needs to limit over travel. The other suggestion is to keep the gun pretty much spotless. An accumulation of crud in the bolt and firing pin channel will cause problems. But even clean guns have broken firing pins so there's really no rhyme or reason. Maybe someone like Navgunner will design a new bolt and firing pin that would eliminate the problem. In the way of our world, it's only time and money. If you have enough you can eliminate most first world headaches.

Does LWRC offer a full auto version of this model? Do you know of any that have been converted? Some designs don't lend themselves to simple conversions. The Olympic Arms OA-93 is a good example. I have a C2 buddy that I work with on projects. He was one of the first to make trips for the Sig MPX and MCX. If anyone could do it he could. But we'd need to see that it's been done before with some success. I'm not even sure which model you are working with. If I understand correctly you need something set up similar to the Daewoo with their shortened carriers.

It's a battle of words. They are correct in the instance that if a firearm is converted to a machine gun that it can only be removed from the registry by being destroyed. There is no other mechanism in their system that allows removal of a machine gun from the NFRTR. Once registered it is assumed by them that it is a machine gun. At this point, you really only have one logical path to take. Find someone to complete the mill and drill work and you have a functional machine gun with value. You're only other option is to completely strip the lower and destroy it per their instructions. You can then get a new semi auto Title 1 receiver and rebuild the firearm. It sucks, but it would cost way more than a new lower to argue your case. Just ask Vollmer. He succeeded in a successful argument against "once a machine gun always a machine gun" but the difference was he didn't register the guns in question as machine guns.