I'm a bolt action guy who is new to semi-auto loading rifles. I was able to acquire an AR-15 look-a-like just barely B4 the frenzy started. It's a CA "correct" Windham "MPC". About 4" inches behind the muzzle the barrel has a smaller exterior diameter an inch long and then returns to the original diameter as it disappears under the hand shroud. Why the variation barrel thickness? Wouldn't this affect barrel harmonics or accuracy down range? I asked Windham but have not heard back yet. I have not fired it yet as the temp at the range is colder than a brass bra on a witch's...well, you know, so I don't know what kind of accuracy the rifle is capable of. With my eyes, 2 MOA would be nice.
