Rolls Royce also produce a machine gun during WW2, they were told to stop buggering about and concentrate on making aero engines, or words to that effect. There was also a NZ semi automatic version of a number 1 Mk3 Lee Enfield, a good idea but a bit bulky.
I would hazard a guess and say that you probably know about the EM2 produce at Enfield Lock, a family friend worked on the EM2 and the SA80. I use to chat to him for hours about firearms, brilliant chap.
Ah yes, the experimental .50 cal aircraft MG! They were going to chamber it in .55 Boys, now that would have been a hell of a machinegun!
If you can get a hold of the 7th edition of
Military Small Arms of the 20th Century by Ian Hogg & John Weeks, there's an image of the gun on page 344. ISBN for the book is 0-87341-824-7 (yes I'm a book nerd, I have that edition along with a couple of others!)
The New Zealand weapon you speak of is the Charlton Automatic Rifle and like the RR machinegun, there's precious few examples left anywhere. There were two versions, the New Zealand model (using Lee-Metford and Magazine, Lee Enfield rifles) and an Australian version (using the SMLE Mk III*) built by, of all things, Electrolux!
Anyway, back to the Thornycroft Carbine, here's some hard data (courtesy of
Military Small Arms of the 20th Century 1st edition, again by Hogg & Weeks)
Built in 1901 as a private venture, the work of James Baird Thorneycroft and according to the authors (who had very good access to the Pattern Room at the Royal Armoury), it handled well and was comfortable to hold and sight).
Calibre: .303 SAA Ball
Length: 993mm (39.12in)
Weight unloaded: 3.40kg (7lb 8oz)
Barrel: 635mm (25.00in) 4 grooves, right-hand twist
Magazine: 5-rd integral box
Muzzle velocity: c.745m/s (c.2450fps)
The Thornycroft Carbine was followed by another private venture, the Godsal Rifle. Designed in 1902 by Major Philip Thomas Godsal but apparently not built until 1904. Godsal was an enthusiastic shooter who had represented England at international shooting competitions on a number of occasions. He designed the Godsal in part to address what he saw as failings in the Lee series of rifles.
Calibre: .303 SAA Ball
Length: 1143mm (45.00in)
Weight unloaded: 3.20kg (7lb 2oz)
Barrel: 756mm (29.75in) 4 grooves, right-hand twist
Magazine: 5-rd integral box
Muzzle velocity: c.747m/s (c.2450fps)
Unfortunately, until I can get another scanner, this is the only image of the Godsal rifle I can find on the net, courtesy of a damned fine page by E. W. Ashworth on the early bullpup rifles found here
http://homepage.ntlworld.com/ernest.ashworth/index.htm His entire site is small but well worth a read if you're a firearms enthusiast.
P.S. Damn! I meant to add I am definitely jealous of you Brit. I've only passed Enfield Lock when I was in the UK in 2010, that's as close as I ever got. It would have been brilliant to be able to talk to someone who actually worked there especially about the EM1 and EM2!