You think they have 1950s technology?
The Davy Crockett
http://www.guntruck.com/DavyCrockett.html
The US development resulted in a number of test weapons. The first artillery test was on May 25, 1953 at the Nevada Test Site. Fired as part of Operation Upshot-Knothole and codenamed Shot GRABLE a 280 mm shell with a gun-type fission warhead was fired 10,000 m and detonated 160 m above the ground with an estimated yield of 15 kilotons. This was the only nuclear artillery shell actually fired. The shell was 1384 mm long and weighed 365 kg, it was fired from a specially built artillery piece by the Artillery Test Unit of Fort Sill, Oklahoma. Around 3,200 personnel were present. The warhead was designated the W-9 and 80 were produced from 1952-53 for the T-124 shell, it was retired in 1957.
The Mk-54 Davy Crockett was designed to be fired from the M-388 recoilless rifle. Weighing only 23 kg the warhead, in its casing, was 400 mm by 273 mm. It was first tested in October 1958 as part of Operation Hardtack and yielded 10 tons, later developments increased that to 1 kt. 400 Mk-54 warheads were produced from 1961-65 and the last was withdraw in 1971. The warhead was also adapted for the Mk-54 SADM (Special Atomic Demolition Munition), this was a cylinder 40 cm by 60 cm and weighed 68 kg, fired by a mechanical timer it had a variable yield from 10 tons up to 1 kt. 300 SADMs were made and they remained in the US arsenal until 1989.
Only one type of artillery round other than the W-48 was produced in large numbers, the W-33 for use in a 203 mm shell. Around 2,000 warheads of this type were manufactured from 1957-65, each was 940 mm long and weighed around 109 kg, they were fitted in the T-317 AFAP and fired from a specialised howitzer. The warhead yield was greater than the W-48 and it was made in four types, three yielding 5 to 10 kt and one 40 kt.
In 1991 the US unilaterally withdrew its nuclear artillery shells from service, and Russia responded in kind in 1992. The US removed around 1,300 nuclear shells from Europe.
Great points, but these sophisticated, small shells —do you know how many tests those required, to get them right? How many tests were there between 1945 and 1953 —we must have been doing...5 tests per WEEK at that time? I’m trying to look it up now..
The Davy Crocket, while interesting was pretty much a self immolation weapon. Fire it, fry yourself. The warheads having more range of damage than the rocket range.
Now there is a lot more technology that goes into a nuke than just the warhead, and it becomes ungainly. I rather doubt the NPRK has the capability to develop some of the essentials needed.
There is also problems with contamination. Tritium, Helium gas and a couple of other elements are byproducts of Plutonium degradation, and reduce the volitility of the warhead. NK's first detonation was a fizzle, probably because of this. Do they have a reliable weapon now? Looks that way, but it's possible they don't have the capacity for the fine machining necessary to manufacturing a true deliverable type of warhead.