While the price is about the same today as a year ago, over the last 5 years the price has increased dramatically, and the price has been very unstable and (I believe) unpredictable over the last year.
I'm just speculating since I am not involved in any way in the ammunition industry, but I would suspect that the manufacturers are:
1) Producing products from raw materials that they bought at the higher prices and wish to recoup those costs.
2) Are not convinced of the stability of commodity prices at even this new higher level.
3) Are taking it in the shorts on transportation costs.