i have a problem! new handi-rifle,polished bore and chamber.loaded first batch .5 grain below max. stuck case,super flat primer. is this common?

Hmmm, starting at a near max load doesn't sound like a good handloading practice to me, regardless of the firearm.

Wrongtarget is right on!
Stuck cases in my HandiRifles have been a problem also. I've found that you have to FULL length size all cases ( all the time ) and back off to the starting loads and work your way up!
Since doing this, I haven't had any problems,and I still get good balistics.

i had this problem in my bull bareled .243. if it still happens, take an extra few thousandth of an inch off the case when you trim them.i did this and no more problem, and also no more not closing and latching problem. hope this helps

I have a 243 NEF Handi-rifle and have loaded for it since it was new. I experienced stuck cases until I really cleaned and polished the chamber. How-ever, I did not experience any flat primers. I agree with the other posts, start low and work up. If you experience accuracy problems, float the barrel by placing a 1/8 thick o ring over the barrel stud. Just my two cents.