I want a scope in the 1-4 or 1.5-5x magnification range, but the really high-end tactical stuff is out of my price range.  However, plenty of companies make scopes in these magnifications for shotguns at prices under $200.  I realize that the main difference is that the parallax is set closer, 50-75 yd vs. 100-150 yd in standard riflescopes.

When cranked up to 4-5x magnification and aiming at a target 300 yd away, will the parallax be bad enough at the relatively low magnifcation to interfere with my ability to shoot groups?  Thanks.

I had a Simmons 2.5x shotgun scope on a M4 for years. Never had an issue, but mine was fixed magnification. 5.56 is a pretty flat shooting round at the distances I shoot (under 200 yards).