Quote:
Originally Posted by
JimBob
| A question for the LE smiths out there.When fitting a bolt head to correct headspace problems is it fitted as is or is it customary to stone or otherwise surface the face of the bolt head to achieve the fit desired? |
Two different answers depending on the LE.
No1's (SMLE) bolt heads were all made 'oversize' and then stoned down by the armourers to give the best (minimum) headspace, When an armourer had amassed a stockpile of 'old' bolt heads he would sort through the box and find one to fit, or one that needed a minimum of stoning.
No4s / No5s
The bolt heads were made in different sizes (as mentioned above) so the stoning was not necessary, the armourer would sort through his stock and fit the one that gave the correct headspace.
BUT
Fitting a new bolt head is not just about headspace.
The bolt body takes a 'pounding' and the ends of the bolt body can start to peen over (just like a Chisel handle when hit with a hammer enough times) this also shortens the bolt and can affect bolt head rotation.
You MUST not have a bolt head over rotating by more than a few degrees or all of the recoil is being taken by the threads and within a 'few' rounds your headspace will be all over the place again.
Before fitting a new bolt head, check it gives the correct headpace and does not over rotate.
The bolt head should align with the big locking lug.
If you cannot get alignment then a new (not secondhand - it may well have the same problem) bolt body may be in order, you may then find that your headpsace is OK with your old bolt head.
Everything is interlinked, change one part and it can affect the next one.
Pictures courtesy of Ed Horton