You need to provide a lot more information such as:
- Caliber you are reloading
- Powder you are using and charge you loaded
- Bullet manufacture and weight
- COAL you loaded (the total length of the loaded cartridge)
- Knowing what type of brass and whether new or already fired would not hurt
Would also be good to know what type of press and dies you used.
There is very little information in your post making it difficult to answer your question.