OK I'm thinking of picking one of these up to chase varmints around the back yard with.  What kind of 50 yard groups are you guys getting out of yours?  Any problems I should know about?

They're great.  I'm at about 1.5-2MOA on mine with good ammo.  The only thing that some friends had to do was tweak on the extractor a little bit.  Mine ran from the get go.  The only downside is the 10 round mags.  Although rumor is that there are 20-25 rounders out there...some where.

Rich

Once every 100 rounds an empty casing will get stuck in the extractor, but that isn't that bad at all. You can simply remove it with your fingers and in the worst case you have to use a set of small pliers. I ran over 2000 rounds since september 2006 and it is the best add-on for my AR.

I found them incredible accurate, with a replica Aimpoint at 25m or with ironsights I shoot everyting in a circle with a diameter of a inch.

And eeeeuh... remove those ugly handguards with a cheap HongKongreplica of the KAC and you can attach all your other toys

Nice set upI will be adding a 6x-18x tactical to mine if I can find one.  Looks like some of the uppers have gone for around $350 on gunbroker.  That a good price?

Quoted: Nice set up I will be adding a 6x-18x tactical to mine if I can find one.  Looks like some of the uppers have gone for around $350 on gunbroker.  That a good price?

Well, I paid Euro 450,- ($600). Cheaper than that you can't get 'm overhere in the Netherlands. So $350 for a new one (or is it used one?) is a very good price compared to here. Still worth every penny!

6x-18x scope sounds good! I'm running a Bushnell 4x-16x-50mm on it for the 100m (110yards) range. Works absolutely fine...

Anyone making an integraly suppressed 22lr upper?

And eeeeuh... remove those ugly handguards with a cheap HongKongreplica of the KAC and you can attach all your other toys

I am thinking about getting a CZ upper.  Where did you get your replica handguard at?