I've got a "new to me" Ishapore No1 MK3 that shows signs of excessive headspace.  A test shot with new/modern ammo produced a distinct shiny ring just above the rim on the spent brass.  There's no bulge, but the ring is noticeable and the brass has clearly "fire formed" to the chamber.  :)  I've included a picture of the fired brass vs the unfired.  The bolt closes on a Forster SAAMI field gauge (which I know is less forgiving than an old school field gauge).  I measured the bolt head at 0.6355" with a micrometer.

I've looked all over for a replacement bolt head that's got more "meat on it" than this one and haven't had any luck yet.    I'm not overly concerned about head separation on new brass, but I was hoping to be able to reload the brass a couple of times. 

It's my father's rifle (and his fathers before that) and he was hoping to shoot it occasionally.  I just want to make sure it's safe to shoot.  Looking for some wisdom on how to proceed.  Perhaps I'm just being overly cautious....

Best,

That's a fairly normal fired .303 case!

The "ring" indicating excess headspace looks like this! & can be checked with a paperclip straitened out one end bent to a "L" shape & run up & down inside the case. If it "snags on something" about 1/2" up from the base it indicates a problem

Ahhh!  Well, OK then it just seems to be excessive caution on my part.  :)

In that case, I'll likely leave the bolt head as it is, clean everything up, replace the broken extractor spring, lubricate, and put it back in service.  Thanks for the sanity check.

Best,

This particular field gauge is marked as .070".  Forster now makes one in the military field spec of .074 (just my luck....that only became available as of a few days ago.  So I'm guessing I'm somewhere just outside of .070, but still within the original spec.

https://www.forsterproducts.com/303-military-field-gage-available/" rel="nofollow - https://www.forsterproducts.com/303-military-field-gage-available/

Perhaps the thing to do is for me to just start buying PPU ammo or pick up some of their unprimed brass.  I only have a couple hundred rounds of the S&B 150gr ammo that I bought for testing.  I'm sure I can find a home for it. 

Best,

The "shiny ring" as you described is actually the part of the case body that does not expand to contact the chamber walls.  It is this area of the case that moves back under the 18.5 tsi chamber pressure and compresses the bolt body.  This is normal. 

As long as the bolt does not lock on a 0.074 FIELD gage, your good to go. 

Appreciate the follow-up.  Yep, it seems I was over-reacting a bit.  

Best,

"As long as the bolt does not lock on a 0.074 FIELD gage, your good to go. "

I'd just add "with MINIMAL trigger pressure, don't crank it. Just one finger lightly".