Printable View
Greetings ,
Am new to this site, and would appericate advice I have a No 4 Mk 2 2/50 of which wanting to chamber for the Epps however am not intirley happy with the head space, the bolt head is marked No1 so what i actually need is a No2 however seem to be drawing a blank as to obtaining one here in South Africa.
So my question is should I remove and setback the barrel one turn, of course then other machining will need to be done.
Numrich in the US have bolt heads and ship to Aus so why not SA
Thanks for information will give shout
---------- Post added at 08:33 PM ---------- Previous post was at 08:32 PM ----------
Meant to say thanks, will give them a call.
The actual measurement (dimension) of bolt heads bears little relation to their 'number'
You can get a size 1 that is bigger (longer) than a size 2 or even size 3. What you need to know is the actual size (length) of your existing bolt head, you need to know by how much your headspace is "off", add the two together and thats the size of the new bolt head you need - you may find it could still be a size 1.
The other equally important point is that the bolt head must 'clock' correctly - you may be lucky but it would not be unusual to have to try 10, 12 or even 20 boltheads to get the correct head size that 'clocks' correctly
Click the link for more info
No 4 No5 Bolt Heads (Update)
And of course, you haven't told us about the gauges that you're using. Some face the same problem as you by wrongly using a .070" No Go gauge. The CORRECT gauge sizes are .064 GO and .074" NO-GO. As has been said here, changing a bolt head isn't just a matter of unscrewing one and screwing another in place. Well, I suppose it could be, but not if you are going to do the job properly. That's why Armourers all undertook long periods of apprenticeships and training.
I suggest you read and inwardly digest an article about fitting bolts that includes bolt heads too as it includes all you need to know about overturn, underturn, lift, striker protrusion and.......... and.......
As Peter has said the dimensions on the bolt heads is fairly arbitrary I have a collection of 1, 2 and 3 here all within a few thou of what the specs say. Follow Peters advice and when you find the length head you need send me the dimensions and will check my spares box to see if I have the magic number for you.
Like I say - and be warned........ Before you go ANY further, check your gauges. You COULD just swop for a longer one, but what about lift, mover or underturn, FPP and all the other associated bits and pieces.
Pamwe, the No 4 is a very common rifle in SA (as you'll know, it was the backbone of the SADF till the late 1960s and thereafter continued in Commando (militia) and SAP units till the 1990s). The various-length bolt heads must be present in abundance. I suggest get a good local gunsmith to sort it out for you. King's seem to be still functioning (in business since before the Anglo Zulu War) at 53 Hunter St, Durban; but there are bound to be others.
I should say, though, that I have (and have had) several S African .303s - none have had headspace problems - I wonder if headspace is the problem - what have you noticed wrong with the rifle?