My opinion on contracting ammo:
Contracts lock in a price. It just depends on your goal. Want to buy ammo at a reasonable price? Contracting is great. Want to sell ammo for big profits? Contracting is not so great.
If you have a corporation selling fighter missiles, and there is huge demand forcing massive immediate orders of fighter missiles for some countries, you're missing out on sales by selling at a static price to yourself. Immediate orders from anywhere on the planet for military goods can greatly increase profits (and you'd be missing out on these). However, if there isn't a big demand, there's virtually no downside to contracting.
Bottom line - it's not bad to do, but there are other viable options as well. Contracting seems to make the most sense in severe shortages or for weapon/ammo types that are quite rare. I wouldn't say I recommend it since I virtually never use it, but I do see it
thnx everyone for the info