Why would DHS need over 1 billion various rounds
Do some work, find the solicitation(s) and read it(them). Post the results for us to see with links to your source material. The SSA solicitation looks pretty reasonable when read and understood.
For example
Solicitation HSFLGL-12-B-00003 (Commerical Leaded Training Ammunition) sounds gigantic at
70 million rounds. Just freaking huge. But by reading the solicitation we see that the ammunition is for TRAINING at the Federal Law Enforcement Training Center (FLETC) in Glynco, Georgia.
The FLETC serves as an interagency law enforcement training organization for 91 Federal agencies. The FLETC also provides services to state, local, tribal, and international law enforcement agencies.
FLETC is a gigantic training facility. So, with FLETC's mission of training 91 Federal Agencies (not counting state, local, tribal, and international) in mind, the 70 million rounds seems less gigantic.
To further explain the solicitation, the 70 million rounds is the
maximum amount that may be purchased under this solicitation. Said another way, the solicitation is for
up to 70 million rounds for one of the larger traning facilities for law enforcement in the United States.
Another factor, which I won't commit the time to, would be to look at the previous FLETC solicitations (keeping in mind their scope may have changed over the years) to see if this solicitation is run of the mill for them.
My original version of this post was curt somewhat dismissive. I apologize for that.