Were the cases "fire formed" in your rifle?
If you have a "sticky bolt" after you fire the new or hand-loaded cartridges during fire forming; when you hand-load then they will take "a little effort to chamber the round" unless you full length size them.
The only time I full length size is when I get a "sticky bolt" after firing. Then I will bump the shoulder back .001"; otherwise I will neck size.
I use a candle to put soot on the case shoulder, then I'll make sure my full length sizing die is set so it will not touch the shoulder. I'll run the case through the die a full stroke and hopefully the soot is still on the shoulder.
I'll then adjust down 1/4 turn and run it though again. I'll keep doing that until the die touches the soot and rubs some off of the shoulder. That should have bumped the shoulder ever so slightly, try it in the rifle and see if it is easy to chamber.
I either neck size, or full length size. There is no need to do both because full length sizing also sizes the neck.
IF, the cases were fire formed in your rifle, and...
If you don't mind the hard to chamber rounds, then go ahead and shoot them... On second thought,
since they are test loads, you might want to invest in a bullet puller. The cases being hard to chamber could skew your results.
[EDIT] Make sure you use lube when full length sizing, lube the case before applying soot to the shoulder.