I've already said <Quote>
everybody tries to blame it one the gun - saying "you've got a headspacing problem", but I think most people actually realize that common 303 British brass is basically made to fail - because the head of the case transitions abruptly to a paper-thin sidewall, creating an obvious weak stressed area.
Since at least one poster doesn't get this - and thinks its just some weirdly coincidental headspacing problem - that effects everything that shoots 303 British, let's look at the facts.
If that were true, why is it that nobody is able to set-up their Lee Enfield rifle to keep from creating case head separation failure problems - in spite of how many times they changed the bolt head to correct headspacing?
Why does no other common cartridge fail, in this area, the way that the Lee Enfield/ 303 British combination produces head separation failures.
For example, why is it that Lee Enfields that have been either made or converted in 308 Win don’t have their fired cases suffer from head separation?
Why do Globco Mohawks exhibit exactly the same heads separation failure problem when they are chambered in 303 British and they never exhibit that problem for those Globco Mohawk chambered in 7.62x54R?
Why do P14’s all suffer from the same head separation problem as L-Es - and the P17 has no such problems?
The answer is it's the defective design of the 303 British case itself.
In a properly designed brass case, there is a region inside where the base of the case meets the sidewall. This is called “
the web”. This super-important web area is present on the inside of any well-designed modern cartridge
and is virtually absent in a 303 British case. This means that the pressure from firing isn’t spread over the rounded internal surface - inside at the web. Rather, the 303 British case INSIDE basically has a flat base that meets a thin sidewall -
at a virtual 90-degree intersection - and all the pressure is focused on that one internal corner.
All of the pressure from that area of the case gets focused on that designed-in zone for failure - and the brass gets thinner and thinner – until the head separates from the case body - at exactly that
pre-programmed zone for failure.
The answer is for case manufacturers to add extra thickness at this point – i.e., increasing case thickness in the area where the web should be.
I have heard that Herter’s case - and perhaps others by Privi etc. - have rectified
the inherent the design flaw of 303 British brass by adding a legitimate web area to the inside of the case.
Case head separation happen because of excessive headspace and overly large chamber. Period. Herter is a very old distributor and I doupt the where making brass, but they stamped their own home brand. Not just brass, dies, reloading tools, clothes also. Think outdoor stores.
Remember military rifle were not build with the reloader in mind. They were made to function in the worse conditions. Check Canadian made Dominion .303 case and they are in specs and as thick case head. Case life in military rifle is often reduced to few firing 5-6 maybe.
Herter is a US brand that was existing in the 30’s to 80’s. (Cabelas using the name in late 70-80’s) They sold civilian brass not military brass.( like Lake City brass compared to Federal commercial brass) usually military case have thicker case, less capacity but loaded to higher pressure.( general)
The British invented and used the .303 round extensively in every war theater in the World. I am sure you can find all kind of old brass since that caliber was put in service in 1888. I doupt the 1888 manufacturing brass is or was on par with WW2 or later brass.
In any case, I use modern case, once fired or new case. Not because it is a old military rifle, that it does not need quality brass for function and safety.
