The simple answer to this is no!
There will be a number of restrictions on your sending many of these products overseas, regardless of whether you send them by post or another means.
1) Carrier restrictions: For example, Parcelforce (the Post Office's international parcels division) specifically prohibits the shipment of any arms and ammunition, and firearms including: imitations and antiques; paint-ball or toy guns; taser guns; air rifles, air pistols, components of firearms and all other items similar to, or resembling the foregoing are prohibited. They also prohibit the shipment of any explosives (even Christmas Crackers etc), any products containing gases.
Other carriers may allow the transport of some of these substances, but there will be restrictions on their carriage, especially where they are considered as dangerous goods (such as explosives, compressed gases, flammable liqueds, solids or gases etc.)
2) Export restrictions: There are restrictions on the export from the UK of many items, including many weapon or military type products. Exportation (whether to a business client or a private individual) is only possible after obtaining an export licence. Export licences are obtained from a divison of the Department of Business, Innovation & Skills, called the Export control Office. You can contact the BIS ECO Helpline on 020 7215 4594 or by email on email@example.com .
3) Finally, there may be restrictions on importation of many of the products you mention, either at a national level, or within specific states of the USA. If goods are refused import customs clearance in the UK they may be returned to you or disposed of at your expense, possibly leading to further consequences.
Hope this gives you some food for thought.