Thread: Headspace question.
Retrieved: 06/09/2014

I have a Savage No.4 Mk1* that will close on the NO GO gauge, but not the field gauge. I assumed that it was safe to shoot, but there is a slight bulge on the fired cases. Would you shoot it?

Edward Horton
02-24-2010

Your Enfield passed its military head space check BUT you're worried because your civilian commercial American SAAMI cases have a bulge.

What you need to understand is American commercial .303 cases are not made to the heavy duty standards of military cases and this applies to ANY commercial cartridge fired in a military chamber

Below, once fired .303 cases from the same Enfield, guess which case is built to military standards and is over .010 (ten thousandths thicker in the base web area at the bottom of the case.

Below the true story of "The Battle of the Bulge"

The thickness and grade of brass is what controls "The Battle of the Bulge" and it is normal for this to happen with commercial ammunition fired in military chambers. Normally military chambers are larger in diameter than commercial chambers and military cases are made thicker to withstand their larger chambers.

Please post some photos of your fired cases to give us a better idea of what is happening.

ireload2
02-24-2010

I would shoot it but exercise due diligence if you reload it.

Parashooter
02-24-2010

Actually the Greek HXP brass shown was probably produced for military use and the Serbian Prvi Partizan brass made for the commercial market. (And neither of them has much to do with "American commercial ammunition or cases".)

For the benefit of new readers, our friend Mr. Horton has reported disappointing results with some brands of .303 brass and seems to enjoy condemning all US-made .303 cases. This doesn't necessarily mean there are genuine problems with either the SAAMI specifications or all US-made .303 brass. Lots of handloaders have had satisfactory results with .303 brass from Winchester and Remington production. Like nearly anything manufactured in large quantity at low cost, there's enough variation in quality and dimensions that occasional problems occur with all manufacturers' production - whether it's American cartridge cases or Japanese automobiles.

If we actually examine the SAAMI .303 cartridge specs, we see that they call for a maximum base diameter of .4601" with a tolerance of .008" under that (.4521"). Cartridges made near the maximum base diameter show very little bulge fired in the minimum .462" chamber specified in both the SAAMI and British drawings below. Cartridges at the low end of the tolerance range and/or fired in a chamber significantly larger than the SAAMI maximum .464" major diameter can show a nasty-looking bulge - but with decent metallurgy and normal .303 pressure (45K c.u.p. per SAAMI) it's no real cause for worry unless expansion exceeds about .015" ahead of the solid web.

tbonesmith
02-25-2010

I'd shoot it, but pick up and install a bolt head that gives tighter headspace when one presented itself.

Edward Horton
02-25-2010

In the United States we have commercial cases and we have military cases, the commercial cases are thinner and lighter and the military cases are heavier and more robustly made.

Commercial American cartridges cases were not designed to shoot in longer and fatter military chambers, Mr. Parashooter and myself have different opinions, this is due to the fact that Parashooter greases or oils his ammunition when he fires it and I keep my ammunition and chamber completely dry and free of all oil and grease products.

Also when a Prvi Partizan case has a larger base diameter and is over .010 thicker than a Remington or Winchester case I call it military grade. The proof of this is in the measuring of these cases with highly accurate gauges and comparing them to U.S. made military cases.

Below, commercial American case on the left and military .303 case on the right.

The new Prvi Partizan .303 cases are even thicker than the military cases pictured below. You will also see below that the factory loaded Winchester case on the left has a more pronounced ring around the base than the thicker military case.

Main point being here is the British Enfield rifle did not go through testing trials using American SAAMI commercial designed cases with smaller head space standards than the British military.

As I said before Parashooter you can't have it both ways and grease your cases with caster oil and then tell people the person with the dry chamber is wrong.

jmoore
02-25-2010

Your rifle is fine, it has a largish diameter chamber to allow it to function in the worst conditions. As long as the brass remains intact for ONE firing then the military was satisfied. Its a Military weapon, not a pampered target rifle being fed a diet of custom reloaded brass. Be happy, and shoot it a bunch!

Edward Horton
02-25-2010

The most complaints generated by the Enfield rifle are related to head space because people are shooting American made SAAMI cartridge cases.

My gauges don't lie Mr. jmoore nor do my photos, the closest you will get today to American "Lake City" military grade cases is by buying Prvi Partizan cases.

Mr. jmoore do you see any bright rings or bulges on the fired factory loaded Prvi Partizan cases below?

Now tell me Mr. jmoore why is it our American manufactures don't even know where to put the shoulder of the British .303 case or why these Winchester cases bulged far more than the Prvi Partizan cases and only lasted for three reloadings.

(Could it be Corporate profits and a cheaper grade brass)

Edward Horton
02-25-2010 SO is his dadgummed rifle safe to shoot? Eh? What?

I do not have this rifle in my hands Mr. jmoore, but this Enfield passed British military head space standards.

The real question is what brand of ammunition did GBinSC shoot in his enfield and a photo of his fired cases would be worth a thousand words.

As a side note to this topic and the quality of American cartridge cases, Remington at one time produced our military ammunition at the Lake City Arsenal but lost the contract to Winchester.

Winchester lost the contract to produce ammunition at the Lake City Arsenal and now ATK Ammunition Systems Group now produces ammunition at the Lake City Arsenal. (The contract went to the cheapest bidder)

Remington was bought out by Cerberus Capital Management and now sells Serbian made Mausers. (Mitchell's Mausers)

And Winchester is now owned by General Dynamic’s weapons division.

Greedy Corporate Companies now run the show and company profits are the bottom line.

In June 2007, a private equity firm, Cerberus Capital Management, acquired Remington Arms for $370 million, including $252 million in assumed debt. This happened because Remington was millions of dollars in debt and did not report a profit during the years 2003-2005.

Cerberus Capital Management, L.P. is one of the largest private equity investment firms in the United States. The firm is based in New York City, and run by 49-year-old financier Steve Feinberg. Former U.S. Vice President Dan Quayle has been a prominent Cerberus spokesperson and runs one of its international units.

I wonder what kind of corporate bonuses are handed out for cost cutting measures at our ammunition plants.

Edward Horton
02-25-2010

If you also look at this Canadian website you will see what a Canadian Armourer has to say about the subject.

"Most gunsmiths use the tighter SAAMI gauges when accessing head space. I said most - not all. If your rifle is assessed as "serviceable" using military gauges, there is a distinct possibility that you will experience more case stretching. If this is so, you might want to tighten up the headspace."

Reloading the 303 British: Chambers and Headspace

Now look at Parashooter's animated .gif image below and watch the case stretch and thin in the base web area. Parashooter's answer for this stretching was to use resizing lube in his "Head Space 101" to keep the cartridge case from gripping the chamber walls.

PICTURE 404

I will end this post with the following statement:

Parashooter's own animated .gif image shows this stretching and thinning and what happens to an American SAAMI designed .303 cartridge case when it is fired in a Enfield chamber. And yet Parashooter decided to bring up MY name criticizing my findings in my initial posting.

What you are seeing here is a war between the case greasers and non-case greasers that has been going on for seven years. And please notice I didn't bring anyones name up in my first posting.

The factory loaded Winchester case below stretched and thinned .009 thousandths in the web area on its first firing and Parashooter wants to tell everyone I do not know what I'm talking about. (I bought factory loaded ammunition just for this testing) The head space on the Enfield that fired this cartridge is set at less than .067, how much do you think this Winchester case would have stretched if the head space was at .074?

The bottom line here is knowing why "some" cases are bulging in the base web area and why other do not and STOP the name calling.

Brian Dick
02-25-2010

His rifle is safe to shoot. I gauged it here myself and also set a bunch of other problems right while he was here. If you're going to reload, take Ed's advice and buy the Privi Partisan cases and a neck sizing die. Fire form your brass and neck size only for maximum case life. I forgot to check the throat erosion while he was here because we had so many other issues to address. My advice there would be to use flat base bullets because the boat tail bullets won't perform as well if there's erosion from the use of cordite which is highlt possible. Try them both and see. The proof is in the pudding. ATB.

Brian Dick
02-25-2010

Oh yeah, almost forgot. Remember what I told you about replacing bolt heads. You might get a good deal on one that you think is the correct size to fix the problem you think you have but the chances are slim that it'll fit and time correctly to your bolt unless you get real lucky. remember that you can lay out ten of any size and they will all measure differently, especially if they are used. The factories and Armourers had bins full of them to select fit correctly.

Edward Horton
02-25-2010

Below in the attachments is a "0" (zero) bolt head that I lapped to give me slightly over a .084 head space setting in the same Enfield that caused the .009 case stretching in the web area at .067 in my posting above.

In this same Enfield at .084 and a rubber o-ring around the case with factory loaded Commercial Winchester ammunition I had NO, repeat NO case stretching in the web area.

I have said this before, I bought 500 once fired Greek HXP cases from Brian Dick and checked each case in three different places with my RCBS case mastering gauge. NOT one single Greek HXP case had ANY case stretching or thinning in the web area.

(NOT all brands of brass cases are the same quality)

The Prvi Partizan cases fired at .067 in this Enfield also had NO stretching or thinning in the base web area of the case.

These gauges below tell no lies and the Remington and Winchester we knew in the past are gone forever in cooperate takeovers.

The rubber o-ring holds the case against the bolt face when fire forming your cases at "ZERO" head space.

After fire forming with the rubber o-ring you neck size only as Brian stated and your .303 cases will then head space on the shoulder, which holds the case against the bolt face at "ZERO" head space.

With the rubber 0-ring you have NO grease or oil on your cases and NO added extra bolt thrust and possible damage to your Enfields.

(You also have the added benefit that the o-ring doesn't care what your bolt head size is or what your head space setting is at)

Surpmil
02-26-2010

Ah, the good old "maximum return to the shareholders"; not forgetting the executives and directors of course...

Naturally they'll make the cheapest case they can safely get away with. They would in fact like nothing better than to find a case that could only be safely fired once.

And if you asked, I'm sure they'd say that is their feduciary duty, to cheapen the product to the lowest point the market will bear without significant loss of sales. And they'll keep cheapening it until they reach that point. It's all very scientific, but sadly fails to take into account the loss of product and corporate reputation and consequent loss of customer loyalty. Anyway, that doesn't happen for several quarters, so why worry about it, eh?!

Edward Horton
02-26-2010

Originally Posted by jmoore
Oiling the case won't affect radial expansion, so leave that bit out!

Oiling the case WILL affect radial expansion, especially when the case can't grip the chamber walls, so lets leave this part in

And here is your "RADIAL EXPANSION of cartridge cases" and all the math and graphs you could possibly want.

Ballistics: Theory and Design of ... - Google Books I even found this graph for you on cartridge pressure ring diameter, but this won't help much because Brian Dick already said GBinSC Enfield is safe to shoot.

Edward Horton
02-26-2010

Originally Posted by torana68
A nifty idea, can you advise what effect this has on accuracy and is there any recorded change in velocity?

Roger you and many other reloaders probably know this already but I will go into a little more depth to help others understand the o-ring method of fire forming.

In most cases when fire forming cases you can simply seat your bullets long with a light neck crimp, the longer seated bullets touch the rifling and hold the case against the bolt face. (zero head space or zero head gap clearance)

I tried several similar fire forming methods but nothing worked because most Enfield's are long throated and the bullets could not touch the rifling. I also tried enlarging the case necks by passing the necks over a larger expander button and have the cases head space on the neck when fire forming, but this led to split necks.

The rubber o-ring trick was posted in another Enfield forum by a Canadian member and he stated it was an old trick used in Canada to make the word head space meaningless in the Enfield rifle when fire forming your cases.

I do not have a chronograph so I can't say anything about velocity other than the pressures and velocity should not be any different from shooting neck sized only ammunition. (the bullet isn't touching the rifling when fire forming)

The o-ring promotes accuracy because as the o-ring is compressed it centers the case at the rear of the chamber, and this helps with commercial American cases as these tend to run on the small side in base diameter.

Any time you fire a light weight commercial cartridge case in a military chamber you run the risk when reloading that the case might be warped or banana shaped because of the larger diameter of the chamber. This causes the base of the case that contacts the bolt face to no longer be flat and true or no longer 90 degrees to the axis of the bore.

The photo below is a graphic example of what I described above as a warped or banana shaped case, please notice the angle of the crack at the base of the case and the crack not being symmetrical around the base of the case.

The Winchester case below was either not centered in the chamber when fired or had a thin spot on the case wall and this caused unequal case expansion on firing and the case warped when trying to spring back to it original shape.

The American Rifleman Magazine printed an article about "banana shaped cases" during the 1970s and the effects on accuracy or more correctly loosing accuracy due to misaligned bullets with the bore.

Please remember military cases are thicker in the base web area and designed to shoot in a military chamber, and our commercial cartridge cases are thinner and lighter and NOT designed to military specifications.

The rubber o-ring method of fire forming .303 cases is the greatest thing to happen since buttered bread or perhaps even putting Vegemite on bread.

Below, 50 fire formed cases using the rubber o-ring method.

Within reason the o-ring makes any Enfield shootable without replacing bolt heads or worring about head space and case head seperations.

Some rubber o-rings and cheap .312 pistol bullets and you have a fun plinking- fire forming day at the range.

Edward Horton
02-26-2010

Originally Posted by Brian Dick "Most of the excessive headspace problem is between the ears of American collectors"

The problem Brian is some people blame the Enfield rifle for a problem that is caused by the type cases you shoot. These people make comments about "inherent weakness", "weak design", "inferior rear locking lugs" and so on.

In over 40 years of reloading this is the closest I have ever come to a case head separation. I also have never blamed the Enfield rifle for any of this or my American made Springfield 03-A3 which was just as hard on commercial cases.

Brian, the 500 Greek HXP cases you sold to me are the same approximate thickness and weight as Winchester .303 cases, BUT there is a vast difference in how many times these two type cases can be reloaded.

And "someone" told Ed to not use Winchester cases

Brian Dick
02-26-2010

Ed, Please don't take offense to my posting which was meant to be in jest if you read it. I fully understand and admire all of your experimentation, trials and tribulations in respect to reloading for the LE rifle. I also know the difference between military specification and commercial specification cases. I use the Greek brass because that's what I have and I've been pleased with the results. I've been reloading for the LE for 30 years, that's since I was 16 years old. I full length size because I have too many different variants of rifles and I like to shoot them all once in a while. I've had case head separations many years ago but only because I pushed my brass one load too many so it was my own fault. It was funny too because some old guy was standing behind me at the range in Florida lecturing me about headspace when every one of 50 popped off consistently. My broken case extractor got a work out that day! I have rifles that gauge up to military specification that shoot average groups and also some that shoot above average groups for my skill level which is low marksman class. Whew, that was fun. Keep up the good work!

Brian Dick
02-26-2010

I had some WWII Winchester cases that I used for a long time along with CanadianDominion WWII cases that were excellent too. If I remember correctly, I got five or six reloadings out of them in a tight '42 date LB No.4 rifle I've had since I was a kid. The Greek HXP brass is the closest thing I've found since.

I've found that most people that criticize the LE action are just sadly misinformed, set in their ways and have probably never owned or fired one. I've converted quite a few Mauser and Springfield shooters over the years and I'm proud of that. I've owned and shot them all over the years and still have a modest collection of many military rifle variants both foreign and domestic. That being said, my favorite rifles in the world will always be the LE No.4 and M1 Rifle. Apples and Oranges they are and I'll always love 'em both!

Edward Horton
02-26-2010

The only "radial" that concerns me are my tires, and as long as they give me good traction and long life I don't care "how fat" they get when I pump them full of air.

The same applies to the brass cartridges I reload, if they fall apart when you reload them, then it's time to look for cartridge cases with deeper tread and a higher speed rating.

For you geeks who want to "see" radial and axial excess case expansion the red and yellow areas below are the parts of your tire that are going to have blowouts.

torana68
02-26-2010

I like the little coloured stress analysis thing, when it was explained to me it was well before computers and was done with calipers, a piece of wire, drawings on paper, coffee and a chat about metalurgy..... sort of left me knowing where to look on most anything man made for the failure point

ireload2
02-26-2010

You can argue two earlier points about brass with this table.

1. Winchester is not the worst brass

2. Military brass is not the best brass.

BTW Lapua is well known for being superior brass but did not show well on this chart.

Edward Horton
02-26-2010

The subject is .303 British cartridge cases and not 308 Winchester cartridge cases that are rated for higher chamber pressure and fired in a commercial SAAMI rifle chamber. Trust me I'm the one who scanned the .308 article.

Your going to have to find a different place for starting your arguments ireload2.

And remember the United States military is warning its servicemen to NEVER grease or oil their cartridge cases. Read item C. below from the US Army Technical Center for Explosives Safety (USATCES), McAlester, OK Risk Management Division. "Excess stress on the weapon" Oily cartridge cases increase force on the weapon's bolt. This over-stresses the bolt's locking lugs and can, over time, increase head space (not good). And in a worst-case scenario, the locking lugs can fail. If the locking lugs fail, you get a blown weapon.

The title of this safety warning is "Don't Lube Your Ammo!" have a nice day ireload2