Winnie, I'm not normally this blunt, but the answer to your question is - YES!!! Take note of the previous responses, an see how you go!

You didn't mention what kind of accuracy you are getting. Also, if you're getting 5 reloads on a belted case and haven't had a case head separation, it may not be that bad of a fireform. DO use a bent piece of wire, though, to check for an internal groove. If you can feel anything grab the sharp end of the wire, that case is done. Pitch it before it separates in the chamber. Brass just isn't so expensive to justify risking a separated case.

I don't advise loading into the lands for anything but single loading for fireforming or target shooting. If you need to extract a loaded cartridge, the bullet can stick in the lands and make quuite a mess for you.

Unfortunately, many factory rifles chambered for belted cartridges have very generous chambers. In fact, sometimes a single firing can stretch a case too much for reuse. The best way to achieve a perfect fireform and enhance the life of the brass is to neck up a notch and neck back down in increments.

Buy a tapered expander in 8mm (.323)and install it in your resizing die. Open up the case neck with the 8mm expander, then replace the expander and neck back down to .30 caliber a little at a time until you achieve a snug fit in your chamber. This is perfect for fireforming. Also, I always use a little Imperial Sizing Die Wax on the case for fireforming. Any brass stretching to fit the chamber will come from the shoulder area rather than from the case body at the pressure ring.

Start with your resizing die at least a full turn or more off the case at the top of the stroke on your press. Turn the die down about 1/8 turn at a time, checking the sized case in your rifle for fit every time. You'll need to remove the firing pin spring from your bolt so you can get a good feel. You'll get to the point when the die starts squeezing the sides of the shoulders enough to slightly push the shoulder forward. Checking for fit in your chamber each time you neck down a little more will eventually give you a perfect fit.

Then it's just a matter of partial full length resizing to achieve bullet grip without pushing the shoulder back excessively. Use the same technique of turning the die down a little at a time and checking for fit when you set up your dies for resizing.

It's kind of a pain in the drain, but your case life will start out on the right foot.

This is the way I've been loading belted cases since 1969. Being a true gun nut, I also neck turn my new cases after rounding the case neck, to within .001" of concentric, and do a final neck turn after fireforming. Then I anneal and I've got a case that's good to go the distance.

Of course, this much work isn't necessary, especially if you're getting good accuracy and case life the way you're doing it. I do it this way because I enjoy it. All my hunting rifles are custom and have very good chambers, so I want to squeeze all the accuracy I can get out of them. The elk won't be any deader if I hit him an inch away from my aiming point, but this what makes some of us tick.