This time travel western is in 7 parts for 63,500 words. Updated version with corrections of errors like dynamite are uploaded on 24 December Australian Time.
I've had a couple of emails about some aspects of the story.
The rifle is an AR-7 which was issued to pilots as a survival weapon for many years (it was designed for that purpose). A .22 LR will kill a person if you hit a critical spot like the heart, lungs, or spine.
The nukes are Tactical Nuclear Weapons meant for quick use in the field as artillery shells, or small missiles, or demolition charges, and are constructed with two sub-critical masses brought to critical mass by violently slamming them together with a small explosive charge (some links below). Many TNWs have been retired from deployment with active service units. Some were dismantled, and some are still stored in armories in case higher command feel they need them. I don't know if any new ones are being constructed, but design work for new units was still going on as late as 2008. A TNW of this type can be set off by an explosion close to them setting off the activation explosives by the explosions of the cannon shells and thus detonate the TNWs, it was one of the known risks with them and a strong argument against their deployment with front-line combat units. In this story the explosive rounds from the cannon (like the GAU 22/A in the links below) going off beside them sets them off at the same time, or so close together it doesn't matter. The four nuclear explosions overlap to create interesting explosions and shock waves.
In the radio operations I called upon what I was taught back in the 1970s. At that time the organisation I was with used the word 'zero' specifically to mean something of nil value and was below 'one' - thus there were 'zero casualties' meaning no one was hurt. The numbers sounded like: zero, one, two-o, three, foour, fieve, six, seven, eight, niner, one oh; they used 'oh' to indicate the units value after a value in the tens column. What did become an issue was when they changed compass reading to be all three digits so what was four, five (45) became oh, four, five (045) - this was supposed to reduce the risks of an error with the first digit being misheard for the lower directions. Other organisations and other countries did use different values and sounds for radio phonetic values. Some examples being names for the letters, like Bob instead of Bravo and David instead of the Delta I was taught, and so on. Any long discussion on this will see many variations listed by different people.
Please, no more emails on these issues listed above.