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Hi guys;

I have a #4mk1/2 converted to 7.62mm that does not have a 19t proofed bolt head. It has withstood this condition for about 15 years but I figure I may as well set things right. Can any UK members put me on to a source for a 1-headspace 19T proofed 7.62mm bolt head for the #4 rifle? I obtained several 19T bolt heads from a fellow in the UK about 5 years ago but I've lost his name and contact information.

Thanks!
 

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I would say 'leave it alone', according to Peter Laidler the difference between a 303 bolt head (proofed at 18.5 tons) and a 7.62 bolt head (proofed at 19 tons) is minimal. When I was building a couple of 'Enforcer Clones' he advised not to bother hunting for a 19T bolt head.

Secondly - just getting a size 1 bolt head is no guarantee of retaining correct headspace. On a survey ( almost 200 samples) I conducted some time ago size the size 1 actual 'size' came out between 0.622" and 0.636".
If yours is currently near the 'top end' and you replaced it by a size 1 at the 'bottom end' of the range you'd be increasing our headspace by 13 thou (0.013").

NEVER quote a bolt head 'size' always quote an actual 'dimension'
 

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A "19T" bolthead is simply a .303 bolthead that happened to be on the rifle when it was proof tested - there is no difference at all. The bolthead (and bolt) are much stronger than they need to be for either calibre; in fact the UK Proof Houses don't have a record of any sort of failure of these components in the hundreds of thousands of rifles they have tested. Current 7.62mm/.308W proof (it is treated as the same calibre in UK Proof) is 20T.
 
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