No. 5 Bolt Head Over Rotation?

Like many others reading the interesting thread on Bolt Head sizes, I went to the gun cabinet to see what bolt heads I have and their sizes. And, having followed the thread on 'bolt-head over rotation', I looked to see what I had. My No.5's bolt looks suspicious, very close to the dreaded 20 degrees overturn and the 4.76mm measurement, if I'm measuring it correctly!

Anyway, here's a pic, what do the experts think?
Attachment 65108Attachment 65109

I've checked the headspace; closes on .064 & .067 but not on a .074

There is no discernible gap between the head and the bolt body with the head lug and the bolt column aligned, a flush fit.

Should I be beating a path to the nearest gunsmith?

Thanks,

Charlie

That overturn is perfectly acceptable. I wouldn't say that about the ringing on the bolt face though Charlie. That is beyond acceptable. But please don't go running to the nearest gunsmith...., please! I'd speak to an Armourer - someone who knows what he's doing!

Peter does it look to your trained eye the radius on the F-Pin seems rather flattened, or the markings on the bolt face is that a sign of hot loads! TIA

Now you mention it, the striker does look a bit flat but whatever caused the ringing is a bit academic. Proper cleaning afterwards will prevent it.

Looks like someone had rammed a cleaning rod into the bolt face repeatedly.

Thank you, most re-assuring, and yes Peter I take your point about finding an armourer (I would take advice from someone like yourself or Mr Quilliam if I went looking).

The bolt face.
It gets cleaned, but I'll admit that I've possibly not been as rigorous as I might have been :red face:. To the naked eye its actually not quite as bad as it looks in the pic. There's no peceptible variation on the face when running my fingernail over it. A dark central ring, possibly carbon?

Hot loads? Not in my keeping. It gets fed a diet of factory PPU and S&B.

Any recommendations on cleaning the marks off, before I get something unsuitable out of the cupboard?

Firing Pin
Hmmm, the top of the pin does look slightly flattened :eek:. Protrusion (measured with feeler guages, I don't have the proper guage) is .048"

Attachment 65131Attachment 65130

Firing pin looks a bit rough. Polishing, by hand, is a quick and easy job. Done carefully, there is little or no effect on protrusion.

https://www.milsurps.com/images/impo.../14e5jj7-1.jpg
https://www.milsurps.com/images/impo.../2w53mh5-1.jpg

Same fine abrasive can polish discolored bolt face - but, unless grossly overdone, won't have any effect on serious pitting (which doesn't appear in your photos). Place oiled abrasive paper on hard, flat surface and rub stripped bolt face in circular motion, only enough to lighten discoloration. Keep face flat on abrasive and don't push down hard. Objective is to polish off only surface discoloration, not shorten the bolt head!

The firing pin tip is acting as a miniature deep drawing die. A die should be as smooth as possible to allow the metal being formed to slide over it and stretch without tearing. If the edges are not properly shaped as in parashooter's left hand profile,or the surface is rough, there is a greater risk of the sheet metal of the primer being torn rather than formed by the "die". I hear that can be rather unpleasant at times. ;)

Think of those movies of helmets being punched out, only imagine them twice as deep as a regular helmet.

I would choose someone who's had a degree of FORMAL training in the craft.............

Thank you Peter, I completely agree. I have heard so many stories of Enfield owners who's rifles have come to grief, even taking them to supposedly well respected old firms.

One last question if I may; I measured the firing pin protrusion from the bolt head at .048". What are the tolerences for this item?

Thanks