Headspace gauges for .303

762mm

762mm

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Hi,

I was wondering where one could buy headspace gauges. I need at the very least the .303 Enfield "field" gauge for two well-used Enfields I need to check and make sure they are safe, as I'm not convinced the headspace is good on them.

I Googled it and there seems to be no links to any place in Canada which sells these .303 gauges, even the basic coin-type kind. If anyone knows where to buy them or has a spare for sale, assistance would be greatly appreciated.

Thanks!
 
Where are you located?

Headspace may be a problem for you but it may just be the massive chambers, had a few brass split on the first shot, factory ammo in a No 1 Mk III* that measures great on headspace, the No 5 rifle just passes on headspace but the fired brass looks a lot better than the No 1 Mk III*
 
Thanks. I am located near Montreal, Qc (unfortunately, lol). I haven't shot these, but I'd like to measure headspace before I do. From what I know, the Enfields are particularly prone to headspace issues due to the locking lugs being at the rear of the bolt, thus allowing the bolt to "compress" over time and create excessive headspace faster than something like a Mauser type rifle, which has the locking lugs in front.

The reason I suspect at least one of them to have an issue with that is because there is resistance upon closing and opening the bolt, like it's rubbing or catching on something (it feels like it's out of spec). It doesn't have that famous "Enfield smoothness" to it, like all the others do. Further, the bolt has a ground off serial number, so it is probably a mismatch. The rifle appears to have shot quite a bit, as the rifling isn't very sharp on it.

Thanks again for the suggestions. Does Brownell's ship to Canada again? They stopped a few years back.
 
i got mine from Brownells and just grabbed the field gauge
I'd have to check the brand , it was a few years ago.
 
762mm said:
Thanks. I am located near Montreal, Qc (unfortunately, lol). I haven't shot these, but I'd like to measure headspace before I do. From what I know, the Enfields are particularly prone to headspace issues due to the locking lugs being at the rear of the bolt, thus allowing the bolt to "compress" over time and create excessive headspace faster than something like a Mauser type rifle, which has the locking lugs in front.

The reason I suspect at least one of them to have an issue with that is because there is resistance upon closing and opening the bolt, like it's rubbing or catching on something (it feels like it's out of spec). It doesn't have that famous "Enfield smoothness" to it, like all the others do. Further, the bolt has a ground off serial number, so it is probably a mismatch. The rifle appears to have shot quite a bit, as the rifling isn't very sharp on it.

Thanks again for the suggestions. Does Brownell's ship to Canada again? They stopped a few years back.
Click to expand...

I think you need to take a step back for a minute.

You said that the bolt does not close without force? Take the bolt out and make sure it is screwed in all the way, had a No 4 bolt like this, it was installed with one revolution out.

Do you have calipers at home? If you do then you can use a cartridge to test for headspace. Measure the rim thickness on the brass, add pieces of masking tape until it gets to 0.067" (SAAMI) or 0.070" (Military), these are the standard NO GO gauge thickness, if the bolt closes on this then go out and find gauges, if the bolt will not drop closed on this you should be fine, the field gauge for both systems is 0.074"

The GO gauge is a rim thickness of 0.064", so your rim thickness will be at this point or less.

Most people see stretching on the 303 Brit and think headspace but the headspace on the 303 Brit is just the rim thickness, the chamber size is what causes the case head issue.
 
The Brits in most cases have sloppy chambers due to crappy QC issues on wartime ammo so you may have enough room for a loaded round and a sock.This is what happened to our Ross rifles as they had nice spec chambers but wouldn't feed the UK ammo so they hogged out the Ross chambers.Some if you reload some use 30-40 Krag brass to correct minor head space as it has a thicker rim.
 
Take a primed case with no powder, no bullet and fire it.. However much the primer backs up pretty well shows how much headspace that rifle has...
 
All great ideas here, thank you all. :)

The cartridge with tape on it idea is something that did not occur to me (I do have calipers), but I'd be afraid of getting a false reading due to tape compression (?). A member here offered to sell me some gauges, which I think is the best option for now.

As for the sticky bolt on that No4, the bolt head is screwed in all the way. I tried another bolt (from a No5 jungle) in it and it also sticks in that No4, but works fine and smooth in the jungle it is matched to. So, it's the receiver on the No4 that's at fault, not the bolt. I'm wondering if that rifle wasn't victim to a hot load or something... as both bolts seems to stick at the long side rib protruding from the bolt and locking into the right side of the receiver. It rubs right above the trigger and there are rubbing marks on that side of the bolt rib. It's almost as if the receiver is a tiny bit too short to accomodate the bolt rib... The receiver is an early Savage with no "US PROPERTY" marking, later converted into a sporter by Birmingham. So maybe just crappy manufacturing?

Weird... :confused:
 
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762mm said:
All great ideas here, thank you all. :)

The cartridge with tape on it idea is something that did not occur to me (I do have calipers), but I'd be afraid of getting a false reading due to tape compression (?). A member here offered to sell me some gauges, which I think is the best option for now.

As for the sticky bolt on that No4, the bolt head is screwed in all the way. I tried another bolt (from a No5 jungle) in it and it also sticks in that No4, but works fine and smooth in the jungle it is matched to. So, it's the receiver on the No4 that's at fault, not the bolt. I'm wondering if that rifle wasn't victim to a hot load or something... as both bolts seems to stick at the long side rib protruding from the bolt and locking into the right side of the receiver. It rubs right above the trigger and there are rubbing marks on that side of the bolt rib. It's almost as if the receiver is a tiny bit too short to accomodate the bolt rib... The receiver is an early Savage with no "US PROPERTY" marking, later converted into a sporter by Birmingham. So maybe just crappy manufacturing?

Weird... :confused:
Click to expand...

That bolt raceway may may just be dirty. I was up at a friends fish camp years ago, they kept an old No 4 under the mattress in case of bears.

That bolt was so awful I spent 2 hours one night with solvent cleaning it up and getting it to run right, it was just really sticky from oil over the years gumming things up.

The bolt head though was something I mentioned because I have seen it done, one revolution tightened up the headspace but too much, you were forcing the bolt closed, thought it was odd and took the bolt out only to find this problem. That particular gun could use a longer bolt head but still passes with gauges but barely, I mean the bolt is mostly down on the NO GO gauge.
 
Fox said:
That bolt raceway may may just be dirty. I was up at a friends fish camp years ago, they kept an old No 4 under the mattress in case of bears.

That bolt was so awful I spent 2 hours one night with solvent cleaning it up and getting it to run right, it was just really sticky from oil over the years gumming things up.

The bolt head though was something I mentioned because I have seen it done, one revolution tightened up the headspace but too much, you were forcing the bolt closed, thought it was odd and took the bolt out only to find this problem. That particular gun could use a longer bolt head but still passes with gauges but barely, I mean the bolt is mostly down on the NO GO gauge.
Click to expand...


Interesting. As mentioned though, I tried it with another bolt which is clean and pristine for sure (nearly new). The same problem occurs. Plus both bolts have been cleaned and oiled. The receiver appears to be the culprit. I'll have to check the safety mechanism, maybe it's interfering with the bolt just a tad, as it closes and opens... I don't know. :(

Ghosts in the machine, lol.
 
mbogo3 said:
The Brits in most cases have sloppy chambers due to crappy QC issues on wartime ammo so you may have enough room for a loaded round and a sock.This is what happened to our Ross rifles as they had nice spec chambers but wouldn't feed the UK ammo so they hogged out the Ross chambers.Some if you reload some use 30-40 Krag brass to correct minor head space as it has a thicker rim.
Click to expand...

Loaded round and a sock.. Best description ever, I laughed out loud.
 
You really need only a No-Go guage.
If it closes easily on a No-Go, then you need to check further.
Someone on cgn makes and sells them, but my set is lost in the bowels of my workshop.
It might be blaser.306. He made my gas check makers.
I have been in error in the past, though.
 
762mm said:
All great ideas here, thank you all. :)

The cartridge with tape on it idea is something that did not occur to me (I do have calipers), but I'd be afraid of getting a false reading due to tape compression (?). A member here offered to sell me some gauges, which I think is the best option for now.

As for the sticky bolt on that No4, the bolt head is screwed in all the way. I tried another bolt (from a No5 jungle) in it and it also sticks in that No4, but works fine and smooth in the jungle it is matched to. So, it's the receiver on the No4 that's at fault, not the bolt. I'm wondering if that rifle wasn't victim to a hot load or something... as both bolts seems to stick at the long side rib protruding from the bolt and locking into the right side of the receiver. It rubs right above the trigger and there are rubbing marks on that side of the bolt rib. It's almost as if the receiver is a tiny bit too short to accomodate the bolt rib... The receiver is an early Savage with no "US PROPERTY" marking, later converted into a sporter by Birmingham. So maybe just crappy manufacturing?

Weird... :confused:
Click to expand...

use copper foil tape from a craft store. the copper will not compress under pressure from the calipers.
A quick way to measure headspace is to use an unfired empty resized case with a spent primer standing proud. Gently close the bolt on the empty cartridge, and gently eject. Measure thickness of the rim and the height the primer stands proud of the case. Add the two numbers together and you get the headspace.
Make sure your chamber is absolutely clean.
 
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