View Full Version : AR-10 conversion

December 19, 2001, 03:20 AM
Presupposing that I have filed all of the proper papers and paid my tax, How difficult is it to convert a semi-auto AR-10 to selective fire? Are there any sources for info on this?

December 19, 2001, 02:58 PM
Unless you are a class 2 manufacturer, it can't be done legally.

Now, there may be registered DIAS or Lightning link available that will work, but those items are the "machinegun."

No post 1986 conversions for civillians.

December 19, 2001, 07:22 PM
Would that be just the receiver that needs to be pre '86?

December 19, 2001, 08:03 PM
Assuming that the internals of an AR10 and AR15 are identically the same, it can be done. I believe that they at dimensionally different, so this thread is a total exercise in mental masturbation. But if you found a registered auto sear for sale, it can legally be installed in a post ban gun. Gun becomes a title three firearm and is exempt from all prohibited dark features. Auto sears are running at about $4000 each. Option number two is spend $6000 on a complete sear gun with a select fire mechanism (if those even existed prior to the 86' ban), cannibalize the gun and install the parts in your post ban gun.

Bear in mind that the 86' ban does not completely prohibit the manufacture of a "new" guns. A sear that was already registered prior to the ban can be installed in any gun that it will fit. Sear is the registered item and not the gun.


December 19, 2001, 08:19 PM

For AR series rifles, a registered auto sear is a DIAS. It is the machinegun.

By a complete sear gun, I assume that you mean a registered receiver gun. It is not possible to "cannibalize" one of these and install the parts in a different gun. In these, the receiver (complete with the hole for the auto sear) is the machinegun.

The '86 ban does completely ban the manufacture of full auto weapons for civillian use (the ATF will not approve the manufacture, and they can not be added to the registry). You got it right when you said that the sear is the registered item. It is "the gun." No new ones can be made for civillian use.

It is not legal to take an auto sear from a registered receiver AR rifle and install it in another rifle. The receiver is registered, not the sear.

They only way to legally do it is with a registered DIAS or Lightning Link (or purchase an origianl Armalite AR-10 (not one of the new manfactured guns).

December 19, 2001, 08:42 PM
I'm not saying using a registered "receiver gun", but using a complete registered "sear gun". Putting a registered "sear" in a gun does not convert to a registered "receiver gun" and the law does allow for that registered "sear" to be moved from gun to gun, including "new" firearms. Providing that the NFA register part was the "sear", the internals can be cannibalized to a new gun and the fantasy AR10 can be made full auto.

There are registered sears, bolts and receivers. Only the registered "receiver" gun cannot be cannibalized of its parts and made into a new gun.

DIAS is the registered part in a "sear" gun.

Now that we have a glossary of terms, are we on the same page now?


December 19, 2001, 11:31 PM
What does DIAS mean/entail?

Can a post ban upper be put on a pre ban lower?

This is not really a mental mastrubation topic. It is something that I have been interested in for many years but didn't have the money to play with before the ban.

December 20, 2001, 02:18 AM

I like shooting them more than I know about them and will do my best to try explaining this. Seen some other guys on this forum that have an excellent grasp on the subject, but they can correct me where I'm wrong and fill in the blanks.

Looks like you are confusing the assault weapons ban of 94' with the machine-gun ban of 86'. Machine-guns are exempted from the 94 ban. Ninety four ban was for title one weapons and machine-guns are title three. In fact, if you happen to come up with the money for a registered auto sear (or DIAS, drop in auto sear. Same beast!), it can be installed in a post ban (94') title one gun and every dark feature that crosses your mind can be done to the weapon, legally. SBR (short barreled rifle), flash hider, bayonet lug, folding stock. Virtually no limits. Assuming we're talking AR's still.

Now, the 1986 ban is a machine-gun ban. Among other things, the law placed a ban on the future production of machine-guns for civilian use. So in other words, there are a finite number of machine-guns across the country. Unless the ban is lifted or another amnesty period is granted and there will be no more than those X number of guns. That is why they are so expensive and desirable.


December 20, 2001, 02:56 AM
And the mental masturbation thing. Sorry!

What I meant to say is if an AR15 drop in auto sear does not fit a AR10 or you can't find a crafty gun smith that can make it fit and work properly. Then, this hole thing is a day dream (thus, the mental spank the monkey!), because it can't happen. Auto sear this the only way to convert the gun legally. There are no existing AR10 registered receivers and no way to make a completely new machine-gun. Only other option is becoming a Class III manufacturer and although fairly easy to do. It is also very expensive to maintain.


December 20, 2001, 10:33 AM
Even if you can find a DIAS, you still cannot add "assault weapon" features to the gun. The rules are exclusive to one another. Machine gun, yes, bayonet lug, no. Go figure. Adam

December 20, 2001, 11:33 AM
Thanks for the explanation. I will look into the M-16 DIAS issue then see about making the batmen happy if it will fit.


Jake 98c/11b
December 20, 2001, 01:38 PM
Hopefully I can avoid muddying the waters further. Agalb is mistaken, I believe, with a DIAS you can have all those evil nasty features prohibited by the 94 ban as it exempted machine guns. I asked about this a few years ago, I was hoping it exempted all NFA guns. I was thinking of building a semi auto M4 but the Technical Branch of the BATF said their interpretation would only exempt machine guns not SBRs. You may want to talk to the tech folks at BATF before you sink a few thousand into a sear that they won't allow you to use as you want. Actually I would talk to a competent smith who has experience with NFA guns to see if it is practical before you do anything else, the Technology Branch will ask questions about how you intend to do the conversion to see if it will fit within their guidlines.

Did that help?

December 20, 2001, 01:48 PM
It sure did. That was more or less what I was going to do. I knew that I couldn't try dropping one in to check the fit unless I had the permission of the demigods in DC first and I couldn't waste my money applying if it didn't fit. So, I was going to ask an expect first.

I'm really not a dumb as I look. I just act that way to catch other off guard.:D

December 20, 2001, 02:06 PM
Guys, machine guns with assault weapon features were grandfathered just like all the semi-auto rifles with the features. Even though a DIAS can be legal, IT is the machine gun. The rifle you put it in is still subject to the assault weapon rules. I am a class 2 FFL/SOT so I do have some background in this area. As always, though, consult BATF for yourself, and don't listen to anyone online. Adam

Jake 98c/11b
December 20, 2001, 02:42 PM
Agalb, I too have been in the industry for a while. Only dealing with MGs off and on but have experience there as well. The DIAS is the MG but as it has been explained to me as long as it is in the receiver (post 94) the receiver is exempt from the restrictions. I don't claim to know the 'current' interpretation of things but this is what I have been told by the tech guys. Rulings, policy and legal interpretations change all the time so all I can say is what I have seen in print. If the DIAS is out of the (post 86) receiver the gun should be disassembled to the point that it no longer has two or more banned features. You wouldn't need to reduce the gun to its component parts if you were to remove the sear for cleaning but I would certainly store the gun with the sear in it. If for whatever reason you wanted to shoot the rifle without the sear in it, the gun would have to be in the politically correct format.

As I have said, I don't claim to be the ultimate authority in these matters. Just puting forth my own experiences, if anyone has any info I don't please educate me.

December 20, 2001, 03:08 PM
The DIAS makes the entire weapon a MG, much the same as a registered receiver does. With a RR you can have an upper with any barrel length, bayonet lug, F/H, etc. Same with whatever rifle the DIAS is in.

HOWEVER - should you remove the DIAS from a post-ban receiver (such as if you were to move it between lowers) the rifle reverts back to post-ban status and all forbidden parts are once again verboten.

Other notes :

"Option number two is spend $6000 on a complete sear gun with a select fire mechanism (if those even existed prior to the 86' ban), cannibalize the gun and install the parts in your post ban gun."

What's a "complete sear gun"? Your first option spoke of the DIAS, so you must mean a RR in this case - especially as you differentiate between the costs of the two. As TaxPhd says, you can't "cannibalize" the parts to make another MG, since it's the receiver that's registered, allowing the factory hole and sear to be installed. If you rip out the Full Auto parts and use them as you please in a semi-auto weapon - not to mention having to drill a hole for the sear - you'd be "conspiring to make a NFA weapon", which is illegal. The BATF has ruled that full auto parts in a semi-receiver (or in the same room as a semi receiver) is grounds for a conspiracy charge.

"There are registered sears, bolts and receivers."

Registered bolts? Where? Certainly not for AR-15/M-16s.

"Ninety four ban was for title one weapons and machine-guns are title three. "....."Gun becomes a title three firearm and is exempt .. blah blah"

There's no such thing as a title three firearm. Title one weapons are long guns (shotguns/rifles), receivers and frames, and handguns. NFA weapons are title two weapons, and many are also title one. This guy probably means Class 3. Which is also wrong There are no Class 3 firearms. There are dealers in NFA weapons usually called Class 3 dealers; they are Special Occupational Taxpayers (SOTs). Class 1 SOTs are importers of NFA weapons, Class 2 are manufacturers.

"Only other option is becoming a Class III manufacturer and although fairly easy to do. It is also very expensive to maintain."

"Class III manufacturer" is the wrong nomenclature again, see above. Have to disagree about it being expensive, though it's somewhat relative. Becoming a SOT requires a FFL, local zoning approval, BATF approval, usually a separate shop or office for business (BATF is frowning on homefront FFLs these days); additionally for the Class 2 SOT (manufacturer) may require EPA checks and typically more zoning approvals. Maintaining the SOT requires a yearly fee ($500-1000, depending on sales), some yearly sales and manufacture of NFA weapons, and documentation (not much more than for the regular FFL). Once you get there - if you're legit - it's not hard to maintain.

Jake 98c/11b
December 20, 2001, 03:47 PM
Almost forgot, there are some pre 86 receiver guns (machine guns) out there but they are not quite the same thing. The original AR-10 is similar to, but not the same as, the current AR-10. But that is another option.

December 20, 2001, 03:58 PM

Posted By: West Texas Ordnance <[email protected]>
Date: 12/12/01 12:38

"2. Pre may AR10, made by AI of the Netherlands. It is in excellent plus condition, and has four waffle mags with it. Gun runs great on surplus ammo. Price is $3550, upfront. I would like to trade this gun for a stripped M16 lower receiver, and if you want to trade I will throw in seven more mags to even the deal up. "

Guy had pics at one time, nice looking rifle. BUT - it is a Pre-86 like Jake was talking about.

December 20, 2001, 11:07 PM
Never claimed to be an expert!

But I think you are all getting a bit hung up on the techno terminology and there in no mystery or mystique to this stuff. Just coming up with enough cash and the right dealer to set you up properly and away you go.

I've seen two types of sears sold. DIAS by themselves at a cost of about $4000 and completed machine-guns with DIAS installed selling for $5500 to $6000. The sear is still the registered NFA item. What's the difference? It's still a sear gun whether complete or just a part. Seen receivers sold the same way, as a part or completed gun. Market has gone so nuts that there is no longer a economic distinction between the two (receiver or sear). Both have become equally as expensive.

Uzi machine-guns have either registered bolts or receivers and was just generalizing the different types of total possibilities.

When you are spending $1000 a year to maintain a manufacturers license in order to own one gun. I think anyone would consider that as expensive.


December 21, 2001, 08:12 AM
If you're lucky, someone might figure out how to add another slot for a tail in a lightning link so that it would work with both AR10s and AR15s (I believe the solid portion at the back of the bolt carrier is longer on the AR10). There are manufacturers out there (Circuits on AR15.com is the only one I know of, but I bet others do it) that can modify a "standard" 3 round burst trigger pack to allow it to work with a LL.