Have you talked to your eye doctor? Assuming you wear glasses.
4 MOA equates to 4" at 100 yards. Far too big for accurate shooting. A 2 or 3 MOA dot will cover the entire black on a standard sighting in target at 100 too.
Have a look at these. Factory 3 Blade Tactical Front Sight. Cost isn't stupid expensive. No mention of how wide the blade is, so ask 'em first.
https://www.ruger-mini-14-firearms.com/Sights.php