I have been really musing over a Kino 12.5 upper that runs on a piston.  It is kind of impractical compared a low profile 12.5 piston setup but I think it would be a fun project.  

Right now the easiest would be to go with a Osprey kit and then find a handguard that will work, most likely two piece and non free float.  There are some handguard tubes that can fit but I would need to unpin the front sight whenever I needed to maintenance the system or break it down.  Everything I've read about the Osprey is that it self cleans so that would be a plus I assume.

But I thought maybe the Syrac would be another option as well.  It would allow for thinner handguards and the ability to adjust the gas settings.  To install would mean I would have to unpin the fsb to put on the Syrac.  The main issue I can see is if the need for maintenance should occur I would need to see if the plug could clear the Syrac and the FSB, then pull the piston out just enough to clear the upper, and then unscrew the Syrac and rotate it to pull out the piston and clean the system.

Just what wondering what everyone else's thoughts are on this setup?  Which way would you guys go or is what I want to do possible at all?

What is your reason for wanting just osprey and Syrac? Is it the handguard size?

The reason for those two are because those are the only ones I know of that could work with the setup I'm thinking off.  I don't know much of the retrofit piston market, if there is another brand that will work I'm all for it.

imo go with a Syrac you can use really low profile floating hand guards. I have never used an osprey system

I'd go with adams arms xlp if you have a standard barrel nut. it's pretty sleek. I use a pretty lightweight free floating handguard and it fits tight,but fiercely.  my hanguard is fortis rev 2.

I recommend anything but osprey. I tried one once, the Nickle coated one, and the gas tube portion was out of spec and would not fit inside of the hole on my gas block (tried 3 different blocks). After sanding it down to fit and installing it, it would not cycle the rifle reliably (failure to eject and failure to lock back on empty). After a few calls to their tech support, and having to listen to the guys story about how he has been a gunsmith at S&W for 20 years and my opinion doesn't matter because of it, I decided to try his advice and try yet ANOTHER gas block. When trying to remove the oversized pin holding the cup to the gas block (its very oversized, plus the hole is undersized due to the heavy nickle coating, and the pin is solid, not a roll pin) I found the pin expanded the piston cup gas tube, causing it to seize into the gasblock. Had to destroy the gas block ($80 gone) to remove the piston cup. I Called osprey again to ask if I could just buy another piston cup, they said no.

After a couple more attempts, finally I emailed MidwayUSA, they offered to take the kit back and give me a store credit. I took that offer in a heartbeat and purchased an Adams Arms kit, with which I've had ZERO issues.

I now have 2 Adams arms kits, and 1 Syrac, love them all. Will never use an Osprey again, even if it was free. Even if I got a lemon that one time, their support team is so stuck up / high and mighty that I never want to deal with them again, plus the fact that they refuse to sell replacement parts.....!?!?

And thanks to MidwayUSA, you guys are great!

Thanks for the information guys.  I think I'm going to drop Osprey from the list.  Now I'm moving towards Syrac Piston or a DI setup with an adjustable gas block.  For those with the Syrac Piston how often do you have to clean the piston and gas chamber?  With the Kino build the FSB is going to be very close to the gas port and carbine piston, so there will be alot of juggling to do to get the thing out without removing the FSB.

You do know that any piston system besides the osprey has it's own gas block, right? You wont be able to have a FSB.

The Syrac piston can be slid out through the gas block, so you don't have to remove the gas block to clean it.
The Adams Arms Standard Piston (railed gas block) is just like the Syrac, in that the piston can be removed through the gas block.
The Adams Arms XLP Piston is different. The gas block is built different for lower profile, which also means the piston can not be removed without first removing the gas block.

None of the pistons systems need cleaning, according to the manufactures claims. Some people still do clean them, but not because they needed it. I haven't put a ton of rounds through mine, but I have put about 500 rounds of dirty Tul Ammo and still haven't cleaned it.

I understand the Syrac has its own gas block.  A Kino is a 12.5in barrel with a carbine gas system and a faux FSB where a midlength gas system would be.  So if you can imagine there will be the Syrac gas block and in front of it will be a FSB.

The setup in my head would be something like this

1) Buy a BCM Kino upper or have a custom barrel made by Adco

2)unpin and remove the FSB

3)unpin and remove the low profile gas block

4)install the syrac piston and gas block

5)pin on the fsb

6)run a two piece free float handguard like a Moe SL, Centurion C4, or DD Omega

Oh, right, my mistake. I forgot that's what the whole point of this was.

In that scenario, my recommendation would be the Adams Arms XLP piston. Once you have everything put together, if you ever needed to clean or replace something, you could simply remove your handguard, then loosen the setscrews on the AA XLP gas block, then slide the gas block forward just a touch (about 1/2") and pull back on the piston/rod, then rotate the gasblock around the barrel. This would probably give you enough clearance to pull the piston/rod out of the upper, leaving your FSB pinned.

The thing I like about the Syrac piston is you can remove the piston rod from the gas black and clean it fairly easy. I take out the piston rod and clean it every 300 or 400 rounds but I think I could leave it in for much longer.  Also the spring inside the piston gas block is very easy to replace. It is nothing more than the spring for an ar mag release. If you go with an adjustable Syrac makes a good one too. I have both in two different 300 blackout builds. Both work great

You will have problems with using a Syrac piston and then putting a faux FSB in front of it. To access the piston for removal and adjustment you will need access to the front part of the piston gas block so with a FSB in the way that is going to be difficult to get to have access. If you are dead set on a faux FSB then I would not use a Syrac piston or Adams arms piston, they were never intended to have a FSB in front of their gas block. I would think your only option would be a piston that uses the FSB. The only one i can think of is Osprey defense.