Quoted:I just picked up a 9" Virtus Pistol. NIB its a PMCX-300B-9B-TAP .
I would like to get a 9" 5.56 barrel for it -HOWEVER I also want to get a rattler length 5.5" barrel for it 300 or 5.56 and see SIG has a rattler 5.56 conversion kit on the website. But says it won't work with an MCX VIRTUS "you need a rattler"
Rattler 5.56 barrel conversion kitWhats the scoop - It won't work? I understand they have some gas mitigation for 5.56. Curious why not? Can the gun I acquired take the 300 AAC Rattler barrel conversion okay? or are their specific other rattler dimensional considerations.
I like the 9" length fine but certainly wouldn't mind having a short conversion to 5.5"
PS where are any 5.56 conversions in stock?
View Quote
The Sig Rattler upper will not be compatible with the Virtus because if you compare the semi-monolothic upper lengths, they're different, in addition to the piston rod lengths not being long enough and therefore incompatible. Because of the top rail length differences, I don't think there is clearance with the gas block. In terms of the 5.5, it's actually about 1.75" longer (with the muzzle device). The muzzle device is actually threaded into the gas block and pinned, so the extra length is a result of that. From what I can see on mine, it looks like the barrel ends inside of the gas block. I've never seen this design before. You'll also have to get the 5.56 compatible handguard because the 300 BLK Rattler handguard will be too short and have a cutout within the handguard that will still work, but look awkward. You have to change the 5.56 Rattler gas from the front and not the side.
Osage County Guns had the 5.56 5.5" conversion I just snagged from them a few days ago. If you're willing to wait, till they get them back in stock, you're looking at paying about $100 less than every other website (including Sig).
Your best bet in this situation is to just get a Rattler 5.56 complete upper.