Headspace dims required

Post by **DuncaninFrance** » Thu Jun 21, 2012 5:03 am

Has anyone got information on the headspace dimension for a Martini-Enfield C 1881 in .577? I believe it is a carbine - possibly Indian Army issue.
A friend has a rifle in poor condition but has managed to acquire some parts and would, like to refurbish it to a high finish.
Sorry, no pictures. I am afraid.

Post by **DuncaninFrance** » Sat Jun 23, 2012 2:39 am

Cm'on you lot, thought this would be where all the knowledge hung out

I have .o6" / 1.5mm from another source and this quote...
I don't know what the headspace would be and the only way you could alter it would be to set the barrel back. Then the extractor might have a bearing on headspace as well.
I don't know if they bothered too much with headspace on them in those days as they were a pretty low pressure black powder load.

Any advance?.........Going once!.............Going twice............................................

Post by **Niner** » Sat Jun 23, 2012 9:18 am

My opinion is that, since it was Indian made it should be the same as on a bow and arrow or slingshot or sharp stick......

However, with apologies for my above smartass remark that I couldn't resist making, a quick google brought up this post by some guys that may or may not know what they are talking about. One of them used to post here but left for some reason or other. I think I rubbed him the wrong way on some response I made to one of his posts........which is something I'm, unfortunately, good at.

http://forums.gunboards.com/showthread. ... head-space

Post by **DuncaninFrance** » Sun Jun 24, 2012 7:39 am

Thanks Robert......

Aughnanure · Post by **Aughnanure** » Sun Jun 24, 2012 6:25 pm

British Mk VII SAA Ball cartridge.
Type Military
Place of origin United Kingdom
Service history
Used by British Empire
Wars Anglo-Zulu War [and even WW I]
Production history
Designed 1871
Variants 11.43×60R (61R)

Specifications

Parent case .577 Snider
Bullet diameter .455 in (11.6 mm)
Neck diameter .487 in (12.4 mm)
Shoulder diameter .628 in (16.0 mm)
Base diameter .668 in (17.0 mm)
Rim diameter .746 in (18.9 mm)
Rim thickness .06 in (1.5 mm)
Case length 2.34 in (59 mm)
Overall length 3.12 in (79 mm)

Ballistic performance
Bullet weight/type Velocity Energy
400 gr (26 g) lead........1,450 ft/s (440 m/s).........1,868 ft·lbf (2,533 J)
480 gr (31 g) lead........1,350 ft/s (410 m/s)......... 1,943 ft·lbf (2,634 J)

Source(s): Handbook for Shooters & Reloaders[1]
Handloaders Manual of Cartridge Conversion[2]

Taken from Wikipedia, when in doubt 'Google'

Rim thickness is given as .06" so allow +0.005 upward tolerance in manufacture for original brass and you get a maximum of 0.065"; so say 0.065" Go and 0.075" No Go.
But they were possibly the same as the later .303 and would be 0.064/0.074.

Pedantic note. It's not a Martini-Enfield, these are .303 calibre.

Post by **DuncaninFrance** » Mon Jun 25, 2012 2:37 am

Thank's Eoin, point already passed on thank you.

Reese Williams · Post by **Reese Williams** » Mon Jun 25, 2012 11:24 am

Duncan,

Send your friend here http://britishmilitariaforums.yuku.com/ and look through the Martini forum. He can probably find the answers in the archives. Several of the members there are MH gunsmiths and will be glad to offer advise and help. Very friendly forum with tons of British weapons knowledge.

Reese

Post by **DuncaninFrance** » Tue Jun 26, 2012 8:24 am

Cheers Reese. I asked Kynoch as well and they sent me the C.I.P. sheet for the 557/450 with Cartridge MAX and Chamber MIN dimensions.

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