Guys,
I know you can’t own this line of rifles, so just thought I’d show them off. 
Out of curiousity, does anyone know if these uppers attach directly to a 556 lower? I was thinking about importing one up here to make it accepty AR mags.
I believe they will.
Oh, and I hate you. 
Say that again after you have to load 30 rounds in six mags.
Yes, a 556 lower will fit without modification. However, the 556 trunion has material relieved from the rear/lower aspect of the trunion just below the feed ramps in order to allow the AR15/M16 mag to appropriately clear and fit. Mapgul P-mags will work without modification, though they will fit rather tightly and will not drop free. USGI-type aluminum mags, HK 416 mags, etc… will not work as they hit the bottom edge of the trunion in the Swiss Arms 55x and will not seat. P-mags and Thermolds will work without modification, but
Here is my SIG/SAN 551-2 with 556 Classic lower and Magpul E-mag. It functions perfectly, though as I mentioned the mags are a tight fit.
How much do the complete SIG 556 lowers go for up there?
To my knowledge they are not officially available in Canada, so the cost would probably be the US price plus the export stamp etc.
They don’t come up on the used market often enough to give a reliable price index.
Thanks for the info guys -
Now - how much does a 556 Lower sell for in the States? With the Canadian $ being close to par with the USD right now, it might be worth while!
The Swiss Arms rifles are not cheap (by my standards, anyway). The newest batch is selling for about $3400+tax, but i got my rifle for $2500, and the carbine for about $3400 (with the $600 B&T rail).
The only reason i’m interested in the 556 lower (and the AR mag capability) is because semi-auto RIFLE mags are limited to 5 rounds. PISTOL mags (like the LAR-15 pistol mags) are limited to 10 rounds. The mags made ‘For LAR-15 Pistol’ just so happen to fit in an AR (:D) so it’s legal to use them in your rifle with 10 rounds.
Sad, strange, but true. Kinda sucks, but then again we can buy 14", 12.5" 8.5" and 6.5" 870 shotguns with just a basic gun license. No tax stamps here! No ‘SBR’ for AR’s either.
Thanks again!
I suppose it could be worse. You could lay in a stash of standard magazines for emergencies.
Complete 556 M4 stock lowers go for $700-ish
Complete 556 original stock lowers go for $1,000-ish with a stock
Complete SIG 550/551 lowers are $2,000+
My SIG 556 has the M4 stock.
The bad thing about the SIG 556 lower that takes original stocks is that no SIG 556 uppers have a rail mounted sling point, so you have to use that little hole on the stock. At least if you have an M4 stock compatible lower you can use any number of M4 end caps with sling mounts.
MFI is supposedly going to make some 550 lowers that take original stocks (who knows when that will be).
But there lies the potential rub. What type of mags are used in the LAR-15 pistol? If they are standard aluminum USGI mags, they will not work with your Swiss Arms receiver with a 556 lower for the reasons I mentioned above. If they are P-mags or Thermolds, you will be good to go.
Yargh. You’re right. Regular old P-Mags must be pinned to 5 rounds up here. The ‘LAR-15’ mags are aluminum.
Well crap - I guess there IS no reason to bring one up then! Then again, I do have 20 of the swiss arms mags, so I should be okay for now.
Thanks guys!