My son and I just recently went in half on 1K rounds of Wolf Gold 55gr ammo ($299.50 after coupon and shipping).
This past weekend, one of my cousins bought a new Sport 2 from the LGS that I dislike VERY MUCH! But, he DID give my cousin a good deal; $536.43 OTD (They know each other). He works nights so we had to wait until today (he's off the next 2 nights) to shoot it.
We field stripped it and cleaned & lubed her up. We used my Grizzly Grease on it. BTW, that's some great CLP!
We loaded up his new PMAG that came with the gun with some WG ammo and he let 'er rip tator chip! She shot great!
So, after a few mags through her, we wanted to experiment.
We took my AR-556 lower and his Sport 2 upper and did some shooting. Nothing changed. It seemed like they were factory. Then, we traded BCG's. His S&W in my Ruger and my PSA Premium in his Sport 2. Still, the same. I had my factory (spare) AR-556 BCG with me, so, we put that in his Sport 2. No change.
All in all, we shot 550 rounds of ammo today. Some of my WG, Wolf steel, and his American Eagle. It was a fun day.
We had to go to his dads barn afterwards to fix a leaking hydraulic hose on a tractor. I was looking around in the barn and came across an old cast iron rooster weather vane. We are going to set that up next time and shoot at it and watch it spin. We live in the country, so, we have to keep ourselves amused.
BTW, the Sport 2 shot great! The one I shot at the range awhile back when I was looking for a new AR, was handled A LOT, making me have the opinion of the Sport 2 as being a "P Oh S." I have to admit, I WOULD buy a new one if I wanted another ENTRY LEVEL AR.

Pretty good little test you did there. I would have expected your results though, milspec guns can swap parts and still run reliably. Glad you have a better opinion of the Sport now, they are great inexpensive ARs.

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Still carrying my S&W 642

Sounds like you too had a good time....
Before ya shoot up the weather vane, Make sure it's not a collectible....

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US Army 71-73 USMC 75-78

You might sell that weather vane and buy a couple sport II's.

Charlie

FIRST what CR said, I would look into selling the C.I. Weather Vain before shooting it! You may be able to get a NICE piece of change for it ! Depending on the markings of who made it 500/1000$ ++++ is not impossible :O and some have sold for 2500 +$ :O
On topic, Glad you like the Sport II I love mine. Good to know the parts swap between your Ruger and the Sport!

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9mm Shield

I waited for years to get the right combination of price and quality for an entry level AR. I thought too many were either over priced or didn't have the quality. The Sport was the answer to that question so I jumped in and bought one. I don't regret it one second. It's everything an AR needs to be. It could of course be better but I'm not complaining. I can make it better if I choose. That's the beauty of the AR system.

I like my S&W Sport II after mine made a trip back to the factory as the headspace was incorrect on it when it came. Now it shoots as it should and I'm very happy with it. They replaced the complete upper and now it shoots great.