The AC556 is way under respected in the NFA world IMO. Just got my tax stamp for my AC556 Blue folder.  First range trip and all I can say is that this MG Rocks! Very fun and the 3 shot selector is very nice. Not sure why the AC556 does not get the love it deserves? BTW I also have an IMI UZI, and used to have a MAC10 .45

Why do you think it is not one of the popular mg's?

Nice score!! I purchased a lightly used one, along with a MAC 10/9, last year and finally picked both of them up from my dealer this past July. I have only taken it out once and ran a couple of mags through it, definitely a fun gun to shoot. I would, however, highly recommend buying as many spare parts as you can find since they are no longer being supported by the manufacturer.

Mags and parts. Mags are pretty easy now but for what seems like forever they were super expensive and hard to find.

Ahh, I got it.  No parts supply puts you up the creek without the proverbial paddle if you break something major.

Off the top of my head and to the best of my recollection: Relatively low production (hence the lack of parts and, for a long time, lack of mags); lack of iconic status ("A Team" and Patty Hearst; anybody remember anything else?); not modular and even the .22LR conversion is out of production, so it's essentially a single, rifle caliber firearm which means more expensive to shoot and may be harder to find places to shoot than pistol calibers depending on where you live; relatively few accessories; it is said to get really hot when shot continuously.

That said, to the best of my understanding, there's nothing really wrong with them; so enjoy many safe times with your AC-556.

Lack of replacement parts is what would worry me.

I have the same gun as the OP, a 13" blued factory folder.  I think I bought mine in the early 2000's for $2500 give or take.  This was the era when Ruger still provided factory support for the gun.

They are not "bad" machineguns by any stretch.  However, there are some challenges to the AC556 that keep pricing down compared to its peers.

One of the biggest contributing factors is the fact that there are just "better guns" out there and a M16 conversion isn't huge financial leap from AC556.   If somebody can afford $10 to $12K for an AC556, they can probably with a touch more saving afford a $17K to $18K M16.

In terms of quantifying the "better guns" statement.

- The original gun the AC556 is based off of (the Mini-14) which is basically the Rodney Dangerfield of the semi-auto rifle world and just gets no respect.   So its more challenged from a pricing perspective to get folks to pay a premium price for  an auto version of a semi-auto gun that has some reputational challenges.

- As a shooter the AC556 is not as smooth a shooter as its primary competitor the M16.  The AC556 also is not as configuration friendly so its more difficult to upgrade (rails, lights, optics, suppressors, etc) and there is the risk of the AC556 looking "Tapco-ed" if it is upgraded with bolt on additions.   Clyde Armory was the only shop that made a good looking upgraded modern stock system for the AC556, but its now out of production.  Other than the Ciener 22lr kit there are really no other caliber options unless you wanted to try and turn one into a 300blk.

- The AC556 (especially the 18" full stocked variety) to be honest just don't aesthetically look the part.   If somebody is spending $10K+ on a machinegun....they generally want it to look like a EBR machinegun.  Probably 99% of the world will think a fixed stock AC556 is a hunting rifle of some sort.  Even gun people will probably say "hey is that an older Mini-14" or if its a folder tell you about the "neat A-Team gun" you got there.   Conversely more than half of the general public thinks an AR15 is a machinegun even though its not.

Personally, I think the 13" guns have a very unique, cool, and distinct look to them but even the 13" version doesn't command a pricetag comparable to other guns that look like machineguns.  (M16, HK33, or FNC)

- As mentioned already parts are not as prolific as other platforms and many folks seem to believe that now that Ruger no longer provides factory service that parts are not available.

I think the parts situation is pretty overblown.  Are AC556 parts as ubiquitous as AR/M16 parts....of course not.  However,  a large number of the primary wear parts are the same as older generation Mini-14s.  Barrels, gas blocks, spring, ejectors, bolts, stocks with minor mods, LRBHO, etc. could all be harvested from an older gen Mini-14.

The majority of the AC specific parts are in the fire control group assembly and if you are really concerned there is pretty much always an AC556 kit available on sturm, gunbroker, etc. for the $1000 range.    Ruger made a lot of post sample AC556s for a decade+ after the ban and there will probably be a long runway of cut up PD guns as they get traded out for M16s or something else more modern.

- There is an impression that the higher capacity magazines are unreliable.  This is probably a reputation earned when Ruger 20rd and 30rd factory mags were more rare and the world was awash in cheap and shitty USA brand Mini-14 mags.   Today its easy to grab some Ruger factory 30rd mags.  However, if you want drum-esque capacity levels your options are a bit more limited.

- There is also virtually no military service for the AC556 in the US and elsewhere its pretty limited.   Machinegun buyers if given a choice will gravitate towards guns with a military pedigree that the AC556 just doesnt have.

Overall I like my AC556 and enjoy it for what it is.  For some odd reason I have always been compelled buy a peer stainless 13" folder as well as I think they are just really cool looking guns.  However,  if forced to give up one of my transferable 5.56 machineguns the AC556 would probably be toward the top of the list to go.

Congrats on the rifle caliber machinegun and enjoy shooting it as they really are (imho) much better machineguns than folks generally give them credit for.

You get some much credit more with a M16 and you don't have to pay they much more.  The ac556 is usually a second or third MG, very rarely the MG someone starts belt collection with.

I have both, ceiner 22 conversion and clyde scar stock for ac556. If anyone looking for one, send me a message

I don't know what this means...

I disagree with this.  I know a lot more people who have started their collection with 9-10k machine guns than 20-25k machine guns.

I have one friend with an AC556, and it is his first & only transferable MG. He chose an AC-556K.

They're interesting, but obviously inferior to an M4A1. One has to pay careful attention to the position of a sheet metal trigger group part (the link positioner assembly - #2) when re-inserting the trigger group, in order to prevent damaging it.


http://www.smallarmsreview.com/display.article.cfm?idarticles=3770

Manual

They heat up very quickly. He avoided a stainless example because they're notorious for barrel discoloration.

If I could find a post sample at a good price I'd get one, but other models interest me more.

I don't know either haha. 90% of my posts are made on my phone and autocorrect can be a bit crazy.

lots of good replies to my OP. My AC556 has been a very good MG. Very reliable and very fun to shoot. The 3 round burst position is a hoot! I'm very happy with my AC-556.

Parts are a bitch, and not likely to improve.

20 rnd factory mags are flawless; 30s are hit and miss

The trigger group assembly damage is greatly over exaggerated in my opinion; don't just jam it in there like it's high school prom night.

The .22 kits are fun as shit; BDM mags work well, until they fall apart.

A bit of history and info here, from 03/10/14.
https://www.guns.com/news/2014/03/10/ruger-ac556-totally-legal-totally-full-auto-mini-14-video

They just dont look tacticool.
A few years back they were the big deal because Ruger fully sported them.
One of the very few factory supported MGs.
Then Ruger stopped.
Prices dropping since.

All this talk about spare parts is weird.
Cannibalize a cheap mini 14.

The same crap was said about FNCs back when they were 7K. NO PARTS !

I agree. Factory 20s have never failed. Factory 30s occasionally give a hiccup or two but are generally reliable. I just picked up some gen II Tapco 30s that get good reviews. Have not tested them yet.

My luck with the tapcos have been spotty, but I think it was earlier generation. Curious to see how your tests go.