When its not quite a .303?

A while back my mate bought a No1 Mk3 SMLE, it was a relatively cheap non mathching numbers gun, that was bought to shoot more so than as a collectors piece.
when we took it out to shoot for the first time we found it was really hard to close the bolt, but once closed it fired and opened up ok, but the brass looked like it had been pushed right up into the bore, which it had.

normal 303 brass on the left, notice the ring on the case mouth of thr one on the right and the longer neck.
Turns out he had unknowingly bought a 7.7x54mm, a round created by trimming off a thread or two from the barrel as a means of getting around the old anti military calibre laws from NSW, a similar 303 Sport was devised in france for the same reason.
my mate doesn’t reload for himself (claims theres no need since I can do it for him lol) so the job of working out how to load for it was left to me.
I manage this by using the rifle chamber to resize the brass after trimming 2mm off of it, then forcing the bolt handle closed, which without a projectile was pretty easy, just awkward.

Before and after of the brass

Some loaded rounds ready for safe shooting.
I was recently talking to a bloke at work about this gun and how I’d told my mate to buy a set of dies and have someone modify them to suit and he gave me a brilliant idea, he said he’d had the same problem (or adventure, depends how you look at these things) he took a shell holder and removed 2mm from the face of it so that then the standard 303 dies would work, just need to buy a much cheaper shell holder and stamp it so as not to mix it up with my other one.

Seems like good work around, mate. How does this thing shoot?

I didn’t do any kind of load development with it yet, just loaded up a hundred rounds with 70% trail boss and hawksbury river cast pill load which can hit a big gong at 100 yards.

That’s pretty smart. But would leave SFA metal. An other solution would be to machine 2mm off the resizing die.

yeah mate that would also work, his logic was a shell holder was only a couple of bucks but a die set would cost 10 times as much. I couldn,t fault the thinking.