AR in .22 build questions..

[moarammo]

What kind of accuracy are we talking about between a dedicated .22lr barrel and a regular AR barrel? The drop of a 22 round is so heavy past 100 yards that I can't imagine that accuracy would be too big of an issue.

[Droppin Deuces]

I noticed a big difference at just 80'. Accuracy will be a little off with just a conversion bolt, but the big difference will come with the amount of flyers you get. You'll be right on the dot for 8 out of 10 shots in a group, and the two that are off will be the 'where the hell did that come from?' type. It can be frustrating, but if you're just going to plink it's not that big a deal.

[dfletcher]

What kind of accuracy are we talking about between a dedicated .22lr barrel and a regular AR barrel? The drop of a 22 round is so heavy past 100 yards that I can't imagine that accuracy would be too big of an issue.

Three issues in the 223 chambering. First, the centerfire bore is a bit large for a 22 rimfire. How much and how bad the effect, I don't know for certain other than to say it probably doesn't help accuracy. Second, there's a fair amount of freebore using the insert - again, I'm sure that doesn't help accuracy. Finally, rate of twist. Most lr's use 1 in 12. Throwing all these little things together made me decide to go with a dedicate 22 lr upper. I got an $89.00 lower, built it up with parts around the house so I figure for about $425.00 I'll have a nice rimfire set up. I may break down and get a RRA 2 stage, that will add $99.00 to the cost.

[lbdrummer3]

I think playing it safe and going with a dedicated up is the way to go. I have to much invested in my firearms to take a chance like that and not enough money to fight it in court if I end up having a problem.
I built up a Sabre lower and put a Model 1 Sales 20" varmint upper on it. I have about 1500 rounds down it so far and it's worked perfectly. Total cost with so so glass was around $900.

[shadow65]

I too would recommend the CMMG dedicated upper.
I have over 4500 rounds down mine with 3 FTE's due to dirt.
Pretty accurate too for a stock barrel.