Re: belted cases, no I'm not in charge but do have knowledge of them that can also be found by any reader of classic Britishicon rifle texts and has even been covered several times in Handloader.

Belted cases as designed by H&H way back when were designed to headspace on the belt. That allowed the case body to be made considerabley undersized. As those were the days of hunting with corrosive primers, cordite powder in nasty, dirty wet places trying to kill animals that fought back, the ability to chamber a round was rather important. You might also note that the British 303 military cartridge used a rim for the same reason and cases bodies are considerably undersized.

Take a look at a 300 or 375 H&H rifle from back in the days that spent it's life on Safairi.
Chamber and bore may be no thing of beauty but when you slammed the bolt home it closed. The "odd" shapes of those old timers like the 300 H&H also contribute to slick as a greased banana feeding.

Reloading was almost unknown so the condition of a fired cartridge either belted or military was of no interest.

Fast forward to post WW II. Almost all cartridges headspace on the shoulder. There is no rational reason for any hunter who maintains his rifle with all the modern wonder products to have a belted cartridge.

However, the cartridge companies producing belted cartridges still headspace them on the belt. When fired the cases expand to fill the chamber, mostly stretching. That weakens the case. Non reloaders don't care, those who do and know it is best for any cartridge to headspace on the shoulder take measures to ensure it does.

All new belted brass is checked for proper chambering as is.

Passing this test, the necks are then opened up to the next caliber. I do all my 300 H&Hs (5) and 300 WinMag (1) to 8mm using a Lyman cast bullet neck expanding die.
(annealing the necks is wise)

Next they are fed into a the original caliber FL sizing die. Moving the die gradually down, you reduce the neck back to it's original caliber. The objective is to create a "false shoulder" ahead of the factory one. It's a test and try procedure until you can just close the bolt with positive resistance. Now the cartidge is headspaced beween the bolt face and the false shoulder. Fire a full load and you have case perfectly fitted to THAT chamber. Neck size only and the cases last forever. If they eventually chamber hard, just touch them with a shoulder bump die. Trimming a bit short never hurts anything either.

This 300 H&H was made in 1948 and still happily uses brass marked "300 Magnum" as back then there was only one ..... one was enough and still is.



Hope some knowledge was passed along.