Do what uncle Ed suggests.

Deep clean the bolt & use a touch of good grease on the lugs & cocking ramp. That should improve bolt opening feel/load.
Note. Some greases don't work with some metal bearing surfaces. For example, I have some teflon filled airgun grease that simply doesn't work well at all on stainless actions. I had a serious stiff bolt syndrome on my Sako 85 which has a stainless action - I now use an "extreme pressure" grease. It makes a big difference in my rifles & my Sako is now slick with proper opening feel.
Many book 223 loads are compressed & don't give excessive pressures.
Don't "chase the lands" just use a book COAL or copy factory rounds for length measured on the ogive.
There is sooooo much ill advised hype online about getting bullets so many thou off the lands. For group size improvement change powder charge (only change one parameter at a time) & concentrate on consistency of your loading & also your firing technique. Shoot at least five (better ten) rounds of each loading (less can give you false impressions of how well that loading suits your rifle).
Pressure can be significantly different if you use different makes of brass - even resulting in pressure signs at low book charge weights in some rifles. - That is why there are published start loads & some data includes brass make.
Ian