BudsGunShop.com - Charging handle

Hi Dan, I would call Ruger and ask for a replacement rifle. Ruger stands behind their products.
Stay safe & have a great day!

Hi Dan and welcome. Make sure the wings on the charging handle are lined up with the slots, make sure a good layer of CLP is on it. The AR likes to run wet--especially new ones.
Lastly, take the upper off of the lower, turn it upside-down, and use a rubber or plastic object to move the bolt carrier group (BCG) to the rear. Make sure the BCG is also lubed with CLP when you do that. The bolt should rotate as you move the carrier to the rear. Watch for that to happen. If it rotates, feel for any resistance to the BCG's continued movement to the rear.
Inspect the charging handle and make sure there are no defects.
Cheers and stay safe!

Take some 0000knot steel wool and rub the internal slide rail or guide a few times this will smooth the metal enough to make slide easy to pull! It will not hurt the weapon i use steel wool for cleaning, polishing, buffing, and debreing my weapons or on some items which may need a little honning such as this. It will not simply take off bluing without bluing remover less you use higher grade wool and really bare down. Then use some hopps oil to lube it these simple steps shall ease your issue! Remember God blesses & Soldiers protect

Take some 0000knot steel wool and rub the internal slide rail or guide a few times this will smooth the metal enough to make slide easy to pull! It will not hurt the weapon i use steel wool for cleaning, polishing, buffing, and debreing my weapons or on some items which may need a little honning such as this. It will not simply take off bluing without bluing remover less you use higher grade wool and really bare down. Then use some hopps oil to lube it these simple steps shall ease your issue! Remember God blesses & Soldiers protect

Here's a thread on your exact problem. Check it out.
rugerforum.net/threads/ruger-ar-556-charging-handle-so-hard-to-pull-is-unusable-new-out-of-box.397479/