AR-15 accuracy issue...

[justintyme8303]

It says .223/5.56 on the mag well.

I've got a 3-9x40 Leupold VX2 mounted in a Nikon M223 mount. It's mounted solidly and there's no play between the upper and lower. The stock is adjustable.

The magwell is stamped but not chambered in any caliber your barrel is and it should be stamped on the barrel with the twist rate. There is a loooong list of calibers that will fit in that same magwell but only 2 will fit in your current barrel 5.56 and .223. Example 300 blackout will fit in the same mags and in that same magwell but not the barrel.

Yes they both fit and fire but there is a slight difference and .223 will not shoot like you want it to out of that barrel if its chambered in 5.56.

.223 Wylde will shoot both more accurately like you are looking for.

https://en.wikipedia.org/wiki/.223_Wylde_chamber