[DURRUTI]

came across this info on wikipediatoday. think this might be some of the reason Minis have had a bad rep in the accuracy departmet?

"Using commercial .223 Remington cartridges in a 5.56 mm NATO chambered rifle should work reliably, but generally will not be as accurate as when fired from a .223 Remington chambered gun due to the longer leade"

I just happened to be out sighting my rifle yesterday and had a bunch of federal 5.56nato, had tight groups. switched to federal .223 and they opened up quite a bit...

I'm sure this has been brought up before, right?

 

[steve4102]

"Using commercial .223 Remington cartridges in a 5.56 mm NATO chambered rifle should work reliably, but generally will not be as accurate as when fired from a .223 Remington chambered gun due to the longer leade"

?

This is simply not true. Yes, the 5.56 has a longer throat than the 223 Rem chamber allowing for a higher pressure round, but they both have a Max OAL of 2.260 which happens to be the longest OAL an AR mag will take. If the 223 round is inaccurate due to excessive bullet jump then the 5.56 will be just as inaccurate as they are the same length.

Barnes did a pretty good study a few years back on OAL and accuracy. What they found was most rifles have more than one OAL sweet spot. One up close to the lands and one or two others much shorter. Don't get caught up it the must be close to the lands hype, it's not that important in a sporting rifle.

.

 

[Jeff F]

I've done the same thing with some 55gr LC NATO rounds and some Federal 55gr fmj .223. I was shooting at 100 yards off a rock solid rest. The Federal opened up a little bit and the POI changed some. Winchester Gr fmj shot the best groups followed by S&B. The S&b seems a little hot to me, no high pressure signs but barked a little more then the other rounds I shot that day. It smelled funny also but seems like good ammo.