Encore barrel closing hard and opening hard

[Selmer]

I traded for a .243 24" factory Encore barrel, like new, no frame marks even, they claimed it had about 25 rounds through it.  With some shells I have to really snap it to make it lock up, and with others it's no problem, all sized the same and freshly trimmed, bullet is about .015 off of the lands.  And no matter what I really have to pull on the trigger guard to make the action open.  My only other barrel is a .454 Casull 12" pistol barrel, factory, and I've never had anything like this with the .454 barrel.  I degreased the locking mechanism on the frame and the trigger and it made no diffence, and I tried lightly lubing it and it made no difference.  Thanks for any suggestions, the barrel shoots good and I can always get it to lock up, I just don't like the hard opening and inconsistent closing pressure.
Selmer

[southern utah]

I just went thru the same thing with a custom barrel. I bought 200 once fired brass in 308 which I FL resized , neck turned and trimed to lenght. I found some worked good and about 1/3 were hard to close and open. The fix was a RCBS small base resizer die. Some of the brass had expanded close to the base and the standard FL resizer "does not resize brass back to factory dementions"(quote from Redding Tech Dept.) . You may have a tight chamber and used brass from other rifles just won't resize small enough with standard dies.