Seems like it’s gonna work fine.  You need the virtus recoil assembly fyi.

Next stop .22lr conversion kit goes in the cnc to work in the Virtus.

Sweet

ETA in for 22lr conversion info

Pic doesn't load for me.

Random thought for the day: I imagine it would be cool to run an 11.5" Virtus barrel in a Canebrake with an over the barrel suppressor like Allen Engineering, Spikes Tactical, or CZ.

That’s pretty close to what it is.

Shot it today.   works fine.  i shot a group at 50 yds that was very very very good.

I’d show you, BUT ar15.com doesn’t do image hosting, and I’m not paying to enrich the forums owners while at the same time creating the content that makes it a good forum to visit.

Every other forum has image hosting included in its basic price because the vendors and advertisement stuff is more than enough to run the place AND pay handsomely.

If you want to email it to me I can throw it up on my imgr account and post it here.

Are you saying if I put the 11.5 5.56 Virtus barrel on my Rattler I need a different recoil assembly? If so why would that be? As far as I know it's just a barrel swap.

Here's mine with the 11.5 barrel and MI handguard. I haven't shot it yet. Not sure why I would need a different recoil assembly. Correct me if I'm wrong.



With standard rattler config.

Yessir.  You need the Virtus recoil assembly.

What happens is the nose of the recoil rod to bolt latch piece is 1” shorter on the Rattler.

So your 11.5 barrels piston won’t reach the bolt assembly to run it.  Single shot only.

If you pull the handguard off you will see it - the end of the piston is just floating there miles from anything.

WOW, I had no idea thanks for the info. Any idea where to get the new recoil assembly?

It’s part number is KIT-MCX-RECOIL.    I may have bought the last one from Osage, but they are out there.

Spendy little bastard at $228.

So:

$228 Recoil Kit
$470 Barrel
$169 hand guard

About $900 all told.  And now you have a spare bolt and some recoil assembly bits.

The handguard is cool with the can on the rattler.  But it would be nice to be able to use Virtus handguards.

The Virtus 11.5 upper itself is out there sometimes at $1500

Just the Virtus upper no barrel or internals is $499.  The bolt carrier is $200.  So it’s break even in some ways to buy a Virtus complete upper and sell the stuff you don’t need than a rattler conversion.

Or even the whole virtus 11.5 as a pistol and be able to swap between pistol and SBR.

If I had to do this again, I would have bought the pistol 11.5” gun and a 6.75 300 no barrel.  The extra inch wouldn’t have killed me.

Thanks for all the info. And here I thought I was all set

Do you have to go back to the Rattler recoil assembly when switching back?

Yes you do - thankfully its easy.   You just pull the firing pin safety lever up hard and slide it out the side.

You know, this kinda pisses me off a little.
The point behind the MCX was everything was modular and could be swapped back and forth, but so far Sig has made every model unique into its own and not interchangeable.

At this point, I gotta ask what's the point of the MCX?

I agree it does suck. All this time I thought I just had to swap the barrel and handguard. Now I have to spend more money. That’s after I can find the damn part. I probably wouldn’t of even bothered buying a barrel and handguard. For $900 I would have just spent a bit more and bought a whole damn gun.

I understand the frustration - however, the Rattler is a different bird.  We offer it on the commercial market in the same configuration as we sold/sell it to a SMU.  It has lots of parts interchangeability, but it does have some unique parts in order for a gun of that size to operate - both suppressed and unsuppressed.

Devils advocate:  if we changed it from the way we sold it to the SMU, people would complain that we changed it up and didn’t offer the “correct” configuration.

If you have a Virtus and want to eliminate the changing of recoil springs, etc, while staying as short as possible, my recommendation is to go with a 6.75” barrel.

I should have just left it be. I really like my Ratter. At this point I just need to find a KIT-MCX-RECOIL. Now that I have everything else. I should have just waited for the Ratter 5.56 barrel

Interchangeability with 556 Rattler will be better suited to the Current Rattler and/or Canebrake models.

As I said, I understand the frustration.  However, I think the benefit is the interchangeability of parts between Virtus and the Rattler/Canebrake - they’re 95% the same, but require some unique parts to function (primarily the Rattler, due to size).

I get that, and I do like my MCX. Don't get me wrong
but we're now on the 3rd version of the bolt.. the current isn't compatible with the first two and the current barrels are not compatible with the older bolts.
then they changed the upper so the newer hand guards do not work with the older "legacy" uppers.
Then add whats being discussed here..

Again, I get it.  Especially when talking about Legacy vs Virtus, bolt changes, handguard incompatibility, etc.

However, the Rattler is a different bird.  Yes, there is interchangeability, but it was never billed as a "plug-in" system with Virtus.  It's really a stand-alone system, that happens to have interchangeability with the full-size rifle - maybe a plug-in URG, but not with barrel swaps.  It just takes unique parts to get a 5.5" barrel to operate suppressed and unsuppressed.

Not trying to battle semantics, just trying to shed light.  If I ever get around to finishing my sticky in this forum, it will better explain interchangeability, like parts, how-to's (like putting a Virtus barrel in a Rattler upper, etc).

This is partially my fault - I have openly discussed putting full-size barrels in my Rattler and vice versa, a 5.5" Rattler barrel in full-size uppers, but I never detailed exactly what was involved.  Whereas, i've hammered away at people to "take the bolt with the barrel", when talking about interchanging Legacy and Virtus barrels (M16-style vs Tapered Bolts) - with the Rattler (either putting the 5.5" in a full-size upper or full-size barrel in a Rattler upper), you need to keep the complete BCG with the barrel, instead of just the bolt (Even though Rattler barrels and full size Virtus barrels share the same tapered bolt ).

It can get confusing and has caused barrier to entry for some who are interested in the rifle, but get frustrated by not understanding the generations, which parts are/are not interchangeable and exactly what is needed to setup their rifle the way they want/have seen.  Hopefully, my sticky will eliminate some of that confusion and, at least, give people a path to understanding.

ETA:  I truly do appreciate the feedback everyone gives here.  I'm not trying to discourage that and it does not fall on deaf ears.  I just want to help where I can in providing answers, solutions and/or reasoning to some of your frustrations.

Or just the spring assembly.  I at least have been using the rattler bolt and carrier with the virtus barrel.

BTW - it works very well after 1000 rounds.

Perhaps a sticky at the top of this forum would be helpful? Something as simple as a list with part numbers would be helpful from an authoritative source.

I might be behind the power curve but I feel like I almost have to white board a logic chart trying to figure out what I need to build a 6.75 .300 LVAW-type system on an AR15 lower and get all the parts correct the first time.

Can you elaborate on what your talking about? Wouldn’t the spring assembly be the same as the recoil assembly?

Yeah.  It’s the same as the recoil assembly.

I got my part I needed for the .22lr conversion CNCd.  It was the first thing I made on my home built CNC machine so it was a rough time getting it to all work and make good parts.

God I miss my Mori Seiki LOL.  That said, the commanded size of this part was .370.   I’ll take 25 hundred thousandths as a variance lol.

Off to try out new .22LR rattler.

@vectorsc

I want one!

I'm still doing analysis on the whole setup.  I found that the 2A 22lr kit this has as the base only really likes 3 different bullets or so.   All of them but one being SUPER expensive for 22lr.   Like how about 9mm prices....

Got a lot of stovepipes out of the kit, and the Boonie Packer Better Mag was a complete failure in this unit.

I was unable to get 1 entire reliable magazine of ammo through this kit...even loading just 5 rounds.

So, next step is to try it with the only ammo they recommend that is affordable.

So so far, its failure.  But the failure is coming out of the kit being used and not the idea methinks.

This is really cool man, I'm totes jelly that you can just "whip up" the parts needed to do this... hopefully you get'er sorted! (I'd be interested in purchasing the parts to make a kit once you do!)

I got a 11.5” mcx sbr and wanted a 9” in 556 but would had to get a hybrid. I was talked Into the 11.5” and glad I got it like the stock better. I had handled the hybrid 9” 556 and liked the stock on it and the short barrel but liked the gen 2 better. I would like a wire stock on a shorty.
I did like the rattler looks but not handed one yet. I myself don’t care about the copper head version. I feel I have to get a rattler while there out there if I get one. Or just do barrel conversion and do maybe 9” 300bo. It would save money and I could get it now but not sure if I want to change barrels every so often or get another rifle lol?
I like the looks of the rattler but silenced 300bo more practical then 556 I think. Its all tempting. I have silencers so a shorty be nice. Honestly a 9” 300bo would be fine.

Now your saying 6.75” barrel and longer just barrel and rail forearm swap only?

Correct. Get the 6.75" .300 black-out barrel and whatever length hand-guard you'd like to use (depending on if you suppress it or not and if you'd like the suppressor concealed a bit inside the hand-guard). I just recently purchased the 6.75" barrel and went a little hay-wire and got 3 different hand-guards. LoL.

Well, I can't say that the 2A .22lr kit worked out.  It was actually issues with the rest of the kits manufacture that did it.   The company tried hard to help me out but in the end it wasn't going to fly.

So...on to making a piece for the .22lr CIENER type kits.

have you tried reducing the recoil spring power on the 22 kit? stove pipes may mean you may not have enough energy to overcome the recoil spring.

The root problem with the 2A kit is that it doesn't pass machining QC...in a lot of ways.

For example there is a lever that sticks out the side of the thing...and if I use the extension piece with a properly made chamber, the lever prevents me from installing the kit in the upper due to the recess being out by 20 thous.

The other big thing is I can't use my M&P mags with the Boonie Packer insert in them with the 2a kit.