You'll want to start by watching the short video I did for my latest project.   It's only 1:49 and there's no talking or annoying music.    

[youtube]http://www.youtube.com/watch?v=GpZ1R6iZk-8[/youtube]

Overall, I'm pretty happy with the way it turned out.   My goal was to fit an AR in a much smaller backpack (not shown) that is very mundane.   While the ability to stow it in a non-descript book bag was prioritized over the sort of reliability and longevity you'd get from a factory-built colt 6920 or BCM carbine, I expect this collection of parts to be fairly trouble free; especially considering I can't afford to shoot tens of thousands of rounds of 300 blackout and don't plan on doing mag dumps til the barrel melts.

For this project I combined 3 unusual components:  
- Shockwave blade pistol stabilizer
- LAW Tactical folder adapter
- Dolos barrel take down system

These parts have been out for a while, but I haven't seen anyone put them together yet.

To make the 8" pistol barrel practical, it is chambered in 300 Blk, and I'm using a Thunderbeast 30-PSS suppressor.  

I'm using subsonic Harvester ammo from Silencerco. (not sure who actually makes it)   It's been flawless so far, though is occasionally supersonic (or at least sounds that way).

Otherwise, the parts are fairly mundane, mostly nickel boron stuff I bought from righttobear.com for what I consider bargain prices.

So this is what it looks like when complete, and taken down as shown in the video, the entire thing fits in a 50 cal ammo can (which I guess technically is a 556 ammo can).



A brief review of the parts:

Shockwave brace:
Not much to say other than it's so much cleaner than the sig brace, and it's cheap and easy.   The screw that holds it onto a pistol buffer tube detent is probably not going to stand up to significant torque though.  

LAW tactical folder:
This is the second one of these I've installed.  I think it's pretty dang handy, but has a major downside and a couple of minor ones.  The major one is that you can't take the BCG out of the rifle quickly.  Instead of popping the takedown pin, hinging the upper off the lower and pulling the charging handle...  you have to open the folder, press the button, pull the BCG out enough where you can get a hand on it, pull the spacer out of it, then push  the BCG back in and return the stock to closed.  Then you can pop the takedown pin and proceed as normal.
It would have been much preferred if they could find a way to add the spacer to the buffer instead of the BCG.

Dolos system:
Honestly, it's pretty neat and reasonably well executed.  It comes apart and goes back together remarkably quickly.  But it was a total pain the butt to procure and assemble.  The instructions were horrible.  And it only works with YHM rails, which means there's no real anti-rotation feature and that jam nut sucks.  (Using an actual YHM barrel nut, there are two holes that you screw bolts into that provide anti-rotation, but those holes don't exist in the Dolos nut, so there's nothing but the jam nut to keep you from twisting it loose.  :(
I hope they figure out how to make this with a higher quality rail.

In the following pictures, the end of the yardstick was aligned with the left side of the part, despite the camera perspective making it look short of that.   So assembled, the total length including suppressor is just under 30".

The YHM 9" rail I used, plus barrel nut, plus the barrel extension protruding (and the gas tube sticks out another half inch past the extension) is about 11".   The receiver itself is about 10.5" collapsed.  And the stock/receiver are about 4" wide when folded.

Cool project.  Thanks for posting it.

I'd not worry too much about the brace exiting the tube detents (assuming you have a KAK pistol tube) as the detents on the tube are formed to where the screw-in stud mates with the detents perfectly. If yours is a tube without detents then yeah, you might have a problem.

I've put near 400 rounds through my recently acquired "bladed" Colt 9mm AR pistol so far with no movement issues. I suspect that the straight blow-back nature of it puts near as much torque on the tube's detents as your .300 would with a much more limited round count.

LOL....Whoo!....I'd hate like hell to have to pay for 400 rounds of .300.

I might be misunderstanding,


but couldn't you put something over the two picatinny rails to latch them together? That would reduce or prevent the barrel from rotating, right?

1srel, yep.  mine has the detents and I don't expect it to twist off in normal use.  

high order.... what would you suggest?   I'm not worried about the barrel rotating.  the barrel extension pin will hold it in place.  I'm concerned the YHM handguard will spin around the barrel nut.  

I haven't posted very many times in here so forgive my not having figured out how to post pictures. I will if I figure it out.

I need to get a different longer railed handguard so as to facilitate irons, and a light/laser combo maybe. The one that comes with it is pretty underwelming. I have been happy with it so far except for one thing. The nut came loose on the release. I tightened it down a bit and used blue loctite.  I however over tightened it just a bit and it was letting the hanguard come loose under recoil!   I talked to the guys at Copper Custom and we figured out the cause was over tightning. I loosened it up a bit and sure enough it stayed tight.  I was wondering where the set screws were for the hanguard nut also. Would have been a good idea.

This maybe will work better. I'm sure this is easy once you get the hang of it. Lol

I'm guessing he means something like this. You could put a red dot on it and mount it between the upper & handguard, so it also serves the purpose of "bridging the gap" between the two and making sure the handguard stays aligned.

Do you really need the rail on the handguard at all?

Mounting a front sight means it's no longer a free float as it would move with any pressure on it. And a railless tube can take either a short rail mount or the accessory could then toggle into whatever compatible mounting hole exists.

In my limited knowledge I haven't seen a tube that can rotate - is this due to the Dolos?

Well that is neat as hell.

Sorry nothing else to offer.

Tired I need the rail for an ir laser

The rotation is kinda due to the dolos. You use their barrel nut with the yhm hand guard. But it doesn't have the holes that the yhm barrel nut has so you can't insert their anti rotation screws

I want to build something just like this-but in 458socom and no suppressor. Cool build...

Tagging for interest.

I have a similar project on my list, only it will be a rifle, not a pistol.  And, I was thinking of using the DRD Tactical system, but lately, I've been thinking the Dolos would be faster on/off.  

I'd be interested in your zero/accuracy after repeated take-downs.

this is awesome, I now have to spend more money what is the longest 5.56 barrel I could fit in a can with a vortex fh on it?

That is sick..
Im leaving this reply here to come back to it later lol..

Can you provide an overall length with the barrel attached but stock folded?

length with stock folded and barrel and suppressor attached is around 21.5"


update on the ammo.  i put my magnetospeed on it and measured the velocity and all were under 1000 fps, so definitely subsonic.  not sure why it sounds loud.  i'm going to try with one of the 9" thunderbeasts and see if it improves

MAC video HERE

Don't waste your time trying to use BUIS with the Dolos, It will never stay aligned! Trust me on this, I've had several of them.

That's the beauty of the Dolos in a .556/.300BLK combo - you can practice/plink with one but tote the other for the superior terminal ballistics and reduced blast signature with only a quick barrel swap.

Just make sure you keep your mags straight - I used entirely different brands of mags for each caliber to avoid any confusion.  Differnet colored mags of different makes would be even better.




I'll confess that in the end I went with two dedicated uppers....damaging the exposed gas tube ends while they rolled around in a bag or box was a concern. But I can see certainly see the added benefit of mating it to a Law folder if maximum length reduction is the goal.

interesting. thanks for the pics guys

Here's my 7.62.....12.5 Faxon barrel......I had an old ATI handguard lying around and it works.....I used three set screws plus the jam nut and it seems to not have any movement.....the BUIS hold close enough to hit a 12" gong at 100 yards over and over after multiple takedowns.....just not much real estate on reciever rail, had to use a cantilever rail to have enough room to use my Co-Mini behind the EO....it packs down pretty small using the IMI folding grip.

I built a upper with a BUIS set up using a YHM flip up front sight.




I also machined a nylon protector for the gas tube although it does add some length when it's taken apart.

I like that protector....better than mine, I'm using a piece of that gray pipe insulation over the end with the gas tube, then slide a beer coozie over each end....