You might consider these "helps"...My little 17 FB and 6mm BR even get baulky now and then when I'm working on loads and does the same thing. Once I got the sizing right, ZERO headspace the cases stopped any shoulder movement and that problem went away. The larger the case the more pressure against the frame face and the more pressure it takes on the latch to open it.
The 22-250 has a fairly large amount of taper which also increases the back thrust...does the same thing in a bolt gun or a T/C...rechambering to a 2-250 AI could help in one way but cause MORE problems in another area...no free lunch. I had a similar problem in my 22-250 Encore, but by rechambering to 22-243 Midd and keeping the pressures down I ended up with about 6% more velocity than a 220 Swift at the same pressure as the original 22-250 and no lockup.
Make sure your sizing die DOESN'T push the case shoulder back on a fired round...back the sizer out a bit...the better the case fits the chamber the less stretching and the less amount of pressure put on the frame face. It's trial and error...run some searches for problems like yours...there are many and lots of solutions.
Sometimes the problems are in the gun...sometimes in the ammo or reloading.
Polish the barrel catch AND the shelf on the barrel....POLISH...don't take off any metal...I use a motodremel tool and a medium cratex wheel...
You can "bed" the barrel in the the frame to help center and take out any slop. I just use JB weld...run a small bead along both frame rails(I use Accra-glass release agent on the barrel and anywhere I don't want the JB to stick)...close the barrel slowly and easy...install the forend and let it sit until the JB starts to set up to a rubbery consistency then you can use an exacto knife to cut off the excess...put it back together and let it set for 24 hours or so. BE SURE not to use very much JB...the gap is small and it is a bear to deal with if you get too much inthe wrong place.
Having the barrel centered without any slop seems to reduce the amount of thumb pressure needed to open the action.
"Normal wear"... cycling through the firing procedure...opening, firing, opening will "wear in" the action over time...practicing dry firing...open, insert an empty case, close, shoulder, lock on a target, cock and squeeze will also help imprint into you muscle memory all the required steps and teach breath and trigger control...helps not be embarrasted or miss that once in a lifetime shot.
Luck