M-16 Pistol ?

Bushwhacker · April 27, 1999, 08:32 PM

Is there any such animal out there?

What would it take to buiding a M-16 pistol, besides getting the class II and all the gestapo paperwork?

Could a AR-15 pistol be converted to M-16?

Rob Pincus · April 27, 1999, 08:53 PM

you mean a full auto AR pistol ?

(I've never enjoyed the semantic debate over whether a gun is an M-16 or an AR -15... to me, an AR with an Auto sear is an M-16...)

What you would need to do is buy ANY AR pistol (patriot or other) and then buy a legal registered Auto Sear or Registered FA lower and attach it to the Pistol upper.

If it were me, and I've owned An AR pistol, I'd much rather have a FA AR-15/M-16 with a short barrel and a collabsible or folding stock of some kind.

I seriously thought about getting a legal SB (8 inch) AR this year, but decided not to invest the money. If I had done it, I was going to look into buying a registered Auto sear and a suppressor as well over the next year or so, so the whole project would've been close to $4000.

------------------
-Essayons

danbrew · April 27, 1999, 10:33 PM

Many of the guns in the AR/M16 family that start life out as a pistol have modified uppers & bolt carrier systems -- what does this mean? It means you can not use "regular" uppers on them. Gotta use their piece of crap upper. I haven't spent a lot of time looking at these, but I would wager that a registered DIAS is not going to work with one of those uppers. And it's not something as easy as dropping in a FA bolt carrier - the bolt carrier for the Olympic pistol is about 3" long. You'd have to be pretty good with the tools to turn it into an auto carrier. I agree with the other poster - get an AR15 and turn it into a SBR or put a short bbl on an M16. Experience has shown that you're going to have to tinker with the gas system on uppers shorter than 11" in order to get them to reliably function. Of course this isn't an issue with the 9mm uppers.

I have a 11" upper on my M16 and it runs like a champ. I also have a 7" (I think) DOE 9mm upper for my M16. Also runs like a champ. I tried a 7" .223 upper and could not get it to consistently empty a magazine on FA. Some folks have indicated that you could open up the gas port, which is located under the front sight post. Too techie for me, however. There was a wonderful write-up in Small Arms Review a few months ago that discussed the problems you could encounter with a bbl shorter than 11" -- essentially the article focused on the fact that the bullet doesn't stay *in* the bbl long enough after it passes the front gas port. The bullet leaves the bbl and the bulk of the gas escapes out the front of the bbl.

I'm running on, moral of the story is to buy an 11" upper and use that as the basis for your short bbl rifle. Going smaller than that length is a problem waiting to happen in the gas system.

danbrew :->

Rob Pincus · April 28, 1999, 10:01 AM

Danbrew's intuition and experience agres with mine, in fact, I had to have the gas port opened on the AR pistol that I did have. It has not one of the modifed patriot type uppers. It was a standard upper with one of those short (3 inch) buffer tubes.
That type of AR pistol will accept any lower, but you could still encounter reliability problems with the shorter barrels.

**4V50 Gary** · April 28, 1999, 08:44 PM

Haven't seen that article in Small Arms Review but I know that is what Ruger did with its family of AC-556 full auto Mini14s. The shorter the barrel, the larger the gas port; and for the reason mentioned above.

Lahti20mm · May 2, 1999, 06:39 PM

The problem with opening up the gas port is that you keep increasing the pressure towards dangerous levels to try to get enough energy (the area under the time pressure curve) to cycle the action. The Army or colt came up with the xm177 (?) flash hider which streaches out the pressure but that won't work in this appication cause it make the barrel longer (against the point of the whole thing) and cause the BATF has decided that it needs to be licenced as a supressor. A fellow recently came up with a great solution. He puts a little tube about 2 inchs long and twice the diameter of the gas tube, in the middle of the gas tube. This sets up a lot of reflections in the pressure wave and streaches out the pulse.
Moral of the story is, not a trivial project, but doable with this new tube. I can't remember where I read about it. SAR?

fal308 · May 3, 1999, 09:57 AM

Yes SAR did a M16 Shorty Diagnostic by Tom Hoel in Vol1 #4 starting on page 12.
My copy of that issue is currently lent out so I can't really tell any more.

April 27, 1999, 08:32 PM	#1
Bushwhacker Senior Member Join Date: January 6, 1999 Location: Somewhere in USA Posts: 323	Is there any such animal out there? What would it take to buiding a M-16 pistol, besides getting the class II and all the gestapo paperwork? Could a AR-15 pistol be converted to M-16?

April 27, 1999, 08:53 PM	#2
Rob Pincus Senior Member Join Date: October 9, 1998 Location: Hotels Posts: 3,668	you mean a full auto AR pistol ? (I've never enjoyed the semantic debate over whether a gun is an M-16 or an AR -15... to me, an AR with an Auto sear is an M-16...) What you would need to do is buy ANY AR pistol (patriot or other) and then buy a legal registered Auto Sear or Registered FA lower and attach it to the Pistol upper. If it were me, and I've owned An AR pistol, I'd much rather have a FA AR-15/M-16 with a short barrel and a collabsible or folding stock of some kind. I seriously thought about getting a legal SB (8 inch) AR this year, but decided not to invest the money. If I had done it, I was going to look into buying a registered Auto sear and a suppressor as well over the next year or so, so the whole project would've been close to $4000. ------------------ *-Essayons*

April 27, 1999, 10:33 PM	#3
danbrew Member Join Date: October 27, 1998 Location: Chicago Posts: 72	Many of the guns in the AR/M16 family that start life out as a pistol have modified uppers & bolt carrier systems -- what does this mean? It means you can not use "regular" uppers on them. Gotta use their piece of crap upper. I haven't spent a lot of time looking at these, but I would wager that a registered DIAS is not going to work with one of those uppers. And it's not something as easy as dropping in a FA bolt carrier - the bolt carrier for the Olympic pistol is about 3" long. You'd have to be pretty good with the tools to turn it into an auto carrier. I agree with the other poster - get an AR15 and turn it into a SBR or put a short bbl on an M16. Experience has shown that you're going to have to tinker with the gas system on uppers shorter than 11" in order to get them to reliably function. Of course this isn't an issue with the 9mm uppers. I have a 11" upper on my M16 and it runs like a champ. I also have a 7" (I think) DOE 9mm upper for my M16. Also runs like a champ. I tried a 7" .223 upper and could not get it to consistently empty a magazine on FA. Some folks have indicated that you could open up the gas port, which is located under the front sight post. Too techie for me, however. There was a wonderful write-up in Small Arms Review a few months ago that discussed the problems you could encounter with a bbl shorter than 11" -- essentially the article focused on the fact that the bullet doesn't stay in the bbl long enough after it passes the front gas port. The bullet leaves the bbl and the bulk of the gas escapes out the front of the bbl. I'm running on, moral of the story is to buy an 11" upper and use that as the basis for your short bbl rifle. Going smaller than that length is a problem waiting to happen in the gas system. danbrew :->

April 28, 1999, 10:01 AM	#4
Rob Pincus Senior Member Join Date: October 9, 1998 Location: Hotels Posts: 3,668	Danbrew's intuition and experience agres with mine, in fact, I had to have the gas port opened on the AR pistol that I did have. It has not one of the modifed patriot type uppers. It was a standard upper with one of those short (3 inch) buffer tubes. That type of AR pistol will accept any lower, but you could still encounter reliability problems with the shorter barrels.

April 28, 1999, 08:44 PM	#5
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 21,832	Haven't seen that article in Small Arms Review but I know that is what Ruger did with its family of AC-556 full auto Mini14s. The shorter the barrel, the larger the gas port; and for the reason mentioned above.

May 2, 1999, 06:39 PM	#6
Lahti20mm Junior Member Join Date: April 13, 1999 Location: Boise,Idaho,USA Posts: 6	The problem with opening up the gas port is that you keep increasing the pressure towards dangerous levels to try to get enough energy (the area under the time pressure curve) to cycle the action. The Army or colt came up with the xm177 (?) flash hider which streaches out the pressure but that won't work in this appication cause it make the barrel longer (against the point of the whole thing) and cause the BATF has decided that it needs to be licenced as a supressor. A fellow recently came up with a great solution. He puts a little tube about 2 inchs long and twice the diameter of the gas tube, in the middle of the gas tube. This sets up a lot of reflections in the pressure wave and streaches out the pulse. Moral of the story is, not a trivial project, but doable with this new tube. I can't remember where I read about it. SAR?

May 3, 1999, 09:57 AM	#7
fal308 Staff Alumnus Join Date: October 12, 1998 Location: Missouri Posts: 1,992	Yes SAR did a M16 Shorty Diagnostic by Tom Hoel in Vol1 #4 starting on page 12. My copy of that issue is currently lent out so I can't really tell any more.