More of a PSA than anything. Might be obvious to some.

So I splurged on an 11.5" Virtus in 5.56 and since I already have a 10.5" ACR and I form 1'd the lower, I thought well hell, I'll buy the 6.75" 300 blk kit from the Sig Store and have some fun with it. Of course, none of my cans fit in the stock HG, so new HG on order. Got a 6" from MWI and it looks fantasic. So I thought well, I'll just dial my XTRII 1-5 in a G mount and note my zeros so I can run the same optic... Not even close. Not close enough to zero at 50 yards within a full rotation of the windage nor elevation knobs. So now I throw on a QD red dot (510c) for the .300 blk upper.

Was at my shooting spot yesterday and realized that I now had the 11.5" Virtus, a 1/2" wrench to remove the G mount, another barrel setup, another can, another HG, another optic, and Torx wrench to remove the barrel, etc... on top of all the usual mags, belts, staple guns, etc.

I say all that to say this: By the time I was done buying shit to be able to swap... I should have just bought a 2nd complete upper or a Hybrid in 300 for not much more. I was really disappointed that I wasn't able to use one optic and the 10" SD handguard. Expensive lesson.

Am I the only one whose barrels are feet apart @ 50 yards? 220gr. S&B subs. And for the obvious question, the 300 was 18" higher and 4-6" left of 556 POI.  Also the 6.75 will only run on '+' with subs and Sandman-L

To me, I always thought swapping uppers like on ARs was a smarter way to go. Optics always stay zeroed to your load and barrel combo.

That's just my opinion, and unfortunately didn't answer your question.
I hope you get a good answer soon though.

To me Sig messed up by not making the virtus different then the legacy. Swapping parts easier was the idea.

Now with that said, should Sig get serious about offering different calibers they could really have something

I agree, but the upper alone was $1,100+ and I would still be two optics deep, so I figured I'd go X-change since the actual swap really isn't bad. But being FEET apart at 50 yards was a shocker. Also not pleased it won't run subs on the '-' setting since the 11.5" 5.56 will run fine unsuppressed on the '-' just lacks LRBHO. I guess I should shoot an e-mail to Sig, but I was hoping others would chime in with their experiences.

Did you try several different subs? I've seen some not cycle where others would.
(not on an MCX, standard AR.. but still)

According to what SIG says. 6.75” barrel is supposed to run suppressed only. Which is why they don’t make a non-SD handguard that fits it.

- is for supers + is for subs. All suppressed. Ymmv

Makes sense I suppose, and the + vs = was really neither here nor there, just a bit surprising to me.

Was really more talking about the barrels being that drastically different POI. Just trying to save someone else a headache and some coin if they had the same idea. In general I have enough 556 and 300 blk setups that I don't need to change it mid-range session, so the current setup will end up working ok, but not ideal.

IMO if you can still find a hybrid for $1,100 or so, just buy it. I may still do that and sell the legacy bbl setup.

I haven't yet. These are S&B 220's that have all cycled unsuppressed in my 6 and 8" AR's without issue. Still burning through factories to build my brass stash before I start reloading them.