.303 Headspacing

[MDR]

I've been reading up on reloading for the .303 and many people recommend an o-ring around the base to prevent headspace issues (something to do with it headspacing on the shoulder rather than the rim afterwards. My question is, after firing the round with the o-ring, do I have to use the o-ring on subsequent firings or is it only needed once?

Thanks

 

[tungngroove2000]

I've been reading up on reloading for the .303 and many people recommend an o-ring around the base to prevent headspace issues (something to do with it headspacing on the shoulder rather than the rim afterwards. My question is, after firing the round with the o-ring, do I have to use the o-ring on subsequent firings or is it only needed once?

Thanks

Just on the 1st firing IF you're going to be neck sizing the case. Any time you full length size you need to use the O-ring again. If you only use the brass in one rifle then you should only be neck sizing for case life anyway.

 

[MDR]

Just on the 1st firing IF you're going to be neck sizing the case. Any time you full length size you need to use the O-ring again. If you only use the brass in one rifle then you should only be neck sizing for case life anyway.

Just what I needed, thanks!

 

[TrxR]

This O-ring idea . Do you just slip the oring over the brass down to the rim?

 

[Great Crouton]

This O-ring idea . Do you just slip the oring over the brass down to the rim?

From what I've read, yes.

My question: Is this for new brass only? What about 1x fired factory?

 

[joe.danay]

Sorry, but adding an O-ring to the cartridge before firing? Something seems off here... I'd be worried about the base of the cartridge being out of battery. I can provide a phone number for a guy in Calgary who did a nice job headspacing my Enfield if you want some pointers. Confederation Firearms, (403) 274-4687. I've never heard of this being done on any rifle, so alarm bells are ringing!

 

[tiriaq]

All the o-ring does is hold the casehead back against the boltface. The body and shoulder of the case can then fireform, without causing an incipient separation. Once formed, the cases are neck sized only, or sized just enough in a FL die to insure smooth chambering.
The o-ring, if it is needed, is used only for the first firing.

 

[saskgunowner101]

From what I've read, yes.

My question: Is this for new brass only? What about 1x fired factory?

It needs to be done on the first firing.

 

[jeff270]

If yer headspace is that bad get it adjusted.

With FL dies you can adjust the dies to neck size (headspace on the shoulder).
or put the Oring under the locking ring if you want to if you want to switch from full length to neck
without messing with the ring.

 

[H4831]

Jeff, I don't think you are quite clear on it.
An awful lot of Lee Enfield's out there have so much headspace that the firing of a factory load, or first time firing of a reloaded new case, will badly stretch the case ahead of the web, making an insipient case rupture.
Even if you neck size that case it is already badly damaged and will have a very short life.
The ring is put over a first time shooting of the case, to keep it in like new condition, so it can be then neck sized and will have a long life.

 

[bigedp51]

In 1914 the British reamed the chambers on their Enfield rifles larger in diameter and longer to the shoulder location to make room for the "Mud of Flanders Fields". Meaning the military chamber is longer and fatter than American SAAMI specifications. Also American SAAMI .303 British cartridge cases are not made to British military standards.

It all started when we Americans thumbed our nose at King George and dumped British tea in Boston harbor. Also after our independence we changed how we spell color and moved the automobiles steering wheel to the other side of the car and made our football players wear protective head gear.

The only concession the U.S. made was to Canada during prohibition, we agreed to play that silly game of Hockey on our side of the border in return for Canadian whiskey.

When the British adopted the metric system the .303 British case was one of the first casualties and American cartridge case manufacturers couldn't figure out where to put the shoulder of the case. (read the story of the "Enfield Inch")

The metric system is so screwed up our American made cases will have the shoulder of the case pushed back too far when full length resized.

All humor aside, the fired case below is now resting on its shoulder, and the amount the case is sticking above the Wilson case gauge is how far the shoulder will be pushed back when full length resizing.

Use the smallest o-ring you can find and grease your locking lugs to prevent galling and wear when fire forming your cases. When the o-ring is compressed it flattens out and centers the case in the rear of the chamber which will aid in accuracy when forming the case. American made cases run on the small side in base diameter and will actually lay in the bottom of the chamber and out of alignment with the axis of the bore.

After fire forming the case will headspace on the shoulder and not the rim and thus hold the case against the bolt face and the o-ring will not be needed.

Also you can use a .303 British case forming and trim die as a shoulder bump die and it will not touch the case body or neck when your cases get too long and the bolt is hard to close.

Below is a once fired factory loaded Winchester case that was fired in a No.4 Enfield rifle with the headspace set at just under .067 and within SAAMI headspace limits. The case stretched and thinned .009 on the first firing, and my point being the case can stretch to meet the bolt face "AND" outward to meet the chamber walls. Meaning headspace, chamber diameter and the cartridge case base diameter affects how much the case will stretch and thin when fired and why the o-ring helps.

The British Enfield rifle doesn't have a headspace problem, the real problem started when we Americans dumped British tea in Boston harbor and didn't make our .303 cases to British military standards.

I don't play Hockey and drink the best beer made in North America.......Bazinga

The Enfield rifle below had its headspace adjusted from .006 under minimum to .010 over maximum military headspace. If you have a good tight fitting bolt head that does not over rotate just use the o-ring method for fire forming your cases.

Besides those rotten Canadians are hiding all the No.3 bolt heads anyway.

 

[aletheuo]

In my experience, i would also lightly oil the case as well as use the o-ring on first firing. Keep sane loads while doing that as there will be more back thrust on the bolt but the cases will be perfectly fireformed for subsequent neck sizing.

 

[bigedp51]

In my experience, i would also lightly oil the case as well as use the o-ring on first firing. Keep sane loads while doing that as there will be more back thrust on the bolt but the cases will be perfectly fireformed for subsequent neck sizing.

aletheuo, I'm going to shoot you in the head with a bazooka.

The whole point in using the o-ring method is so you will "NOT" lube the case which doubles the bolt thrust and increases wear and the headspace on the Enfield rifle. The 1929 British Textbook of Small Arms tells you to remove all oil and grease from the chamber and cartridge of the Enfield rifle before firing or else the action will be strained.

Now guess why the Enfield rifle has replaceable and "LONGER" bolt heads and "WHY" they need replacing. And guess what causes bolt head over rotation and the peening of the two mating surfaces.

The only time you need to lube your "cartridge" is when your wife or girlfriend are not around and you feel the urge to fire your weapon.

 

[burnt_servo]

you guys also know that different companies make the rims a different thickness on the 303 .

and since the 303 is ment to headspace off of the rim , this can cause what appears to be a headspace issue , when it is actually a issue of brass not properly being made .

off the top of my head there can easily be 10 thou difference in rim thickness from one company to another . ( smelie had some pretty good posts about this a couple years ago .... thank you smelie )

(reloads can be made to headspace off of the neck , by fireforming and necksizing .... or at the very least not pushing the neck back when resizing .)


unless there is a serious , real , headspace problem . a guy should be able to fire factory rounds without issue .

the only time when the "headspace " issue rears its head is when the rounds are reloaded .

 

[jeff270]

That's all a little bit nuts . If the chamber is oversize I'm still thinking that a 303 with good headspace
(on the rim) is equivalent to making 300 H&H into 300WBY. Not too harmful to case life.

Rifle Loonies, God love em.

 

[flying pig]

Yes and no. Some ppl are crazy about headspace issues with Lee-Endields, but the only .303 case head seperation I've had yet was in a MkIII Ross with good headspace.

 

[bigedp51]

Headspace is also the distance between your ears and how well you use this space.

And excess headspace comes in many forms and getting 32 reloading out of a .303 British case is like getting a full glass of beer. And its up to the reloader to determine if the glass is half full or half empty.

Its a lot like drinking Taqulia, there's always someone who sucks on the lemon too long and then complains.

 

[H4831]

Well Biged, I'm wondering about this tea dumping affair. You made this statement, "It all started when WE Americans thumbed our nose at----". What I am wondering is if your fore fathers were in Massachusetts in 1773, in order for you to use the word "we".
Because my great, g,g,g,g,g,g,g,g,g, (however many greats,) grand father landed at Massachusetts Bay in 1630, 143 years before WE dumped the tea in the harbour.
He, his wife and infant son were on one of the first four ships of the Winthrop fleet, who landed at Salem, Massachusetts, June 13, 1630. He was actually on the same ship as John Winthrop, who was named the governor of the fleet. These were the Puritans, who were fed up with the English government and pulled out.
I have proof of what I have written because a family member has been working on the family tree for years and spent last summer holidays in Boston, getting the final information. They were 99 per cent sure they had it correct, which was verifying something my father had always said, that he was a direct descendant of the L---- that landed in Massachusetts shortly after the Mayflower, but they required a male L---- to take a DNA test to prove it.
I took the test and it proved out, I am a descendant of the L---- who was on the Winthrop fleet!
So Ed, I just want to be sure of whether or not, you were one of the "WE," who dumped the tea.

 

[kamlooky]

In 1914 the British reamed the chambers on their Enfield rifles larger in diameter and longer to the shoulder location to make room for the "Mud of Flanders Fields". Meaning the military chamber is longer and fatter than American SAAMI specifications. Also American SAAMI .303 British cartridge cases are not made to British military standards.

It all started when we Americans thumbed our nose at King George and dumped British tea in Boston harbor. Also after our independence we changed how we spell color and moved the automobiles steering wheel to the other side of the car and made our football players wear protective head gear.

The only concession the U.S. made was to Canada during prohibition, we agreed to play that silly game of Hockey on our side of the border in return for Canadian whiskey.

When the British adopted the metric system the .303 British case was one of the first casualties and American cartridge case manufacturers couldn't figure out where to put the shoulder of the case. (read the story of the "Enfield Inch")

The metric system is so screwed up our American made cases will have the shoulder of the case pushed back too far when full length resized.

All humor aside, the fired case below is now resting on its shoulder, and the amount the case is sticking above the Wilson case gauge is how far the shoulder will be pushed back when full length resizing.

Use the smallest o-ring you can find and grease your locking lugs to prevent galling and wear when fire forming your cases. When the o-ring is compressed it flattens out and centers the case in the rear of the chamber which will aid in accuracy when forming the case. American made cases run on the small side in base diameter and will actually lay in the bottom of the chamber and out of alignment with the axis of the bore.

After fire forming the case will headspace on the shoulder and not the rim and thus hold the case against the bolt face and the o-ring will not be needed.

Also you can use a .303 British case forming and trim die as a shoulder bump die and it will not touch the case body or neck when your cases get too long and the bolt is hard to close.

Below is a once fired factory loaded Winchester case that was fired in a No.4 Enfield rifle with the headspace set at just under .067 and within SAAMI headspace limits. The case stretched and thinned .009 on the first firing, and my point being the case can stretch to meet the bolt face "AND" outward to meet the chamber walls. Meaning headspace, chamber diameter and the cartridge case base diameter affects how much the case will stretch and thin when fired and why the o-ring helps.

The British Enfield rifle doesn't have a headspace problem, the real problem started when we Americans dumped British tea in Boston harbor and didn't make our .303 cases to British military standards.

I don't play Hockey and drink the best beer made in North America.......Bazinga

The Enfield rifle below had its headspace adjusted from .006 under minimum to .010 over maximum military headspace. If you have a good tight fitting bolt head that does not over rotate just use the o-ring method for fire forming your cases.

Besides those rotten Canadians are hiding all the No.3 bolt heads anyway.

Rotten Canadians you say?
I do believe this site is labeled CGN .......also known as Canadian Gun Nutzs.
You sure don't wish to hear what I have to say 'bout you south siders.
What gives you the right to call me a Rotten Canadian?
Do tell.

 

[burnt_servo]

Rotten Canadians you say?
I do believe this site is labeled CGN .......also known as Canadian Gun Nutzs.
You sure don't wish to hear what I have to say 'bout you south siders.
What gives you the right to call me a Rotten Canadian?
Do tell.

he probably got stuck in a elevator with several Canadians who had stinky moose pepperoni farts ....