My 1903 M/S altered to 256 Gibbs Magnum (Geo Gibbs, Bristol, England) uses the original 1903 magazine, no alterations to the cartridge cuts. The cartridge guide ring at the front needed thinning on the inside edge to allow the case and bullet to feed as the rounds being slightly larger in dia sit up in the orig magazine cartridge inlet cuts.
The 256 Gibbs Magnum I make with 6.5Swede reloading dies. The FL sizer (cheap priced used LEE set) is shorted a touch to be able to push the shoulder of the case back a bit. The case length is 54mm instead of the Swede 55mm.
.471 case head,,no bolt face alteration and it doesn't appear to be any extractor alteration either.
I make the cases from new 8mm Mauser brass,,just happen to have a bunch of it. Could use a number of different choices. The slightly larger Swede case base dia does not seem to be in play in the Gibbs conversion.
It was probably a quick way to a proprietary round at the time. Uses the orig bbl, ect.
I have no doubt that the 6.5 Swede round could be made to work just as well in the action and I have seen more than a few custom M/S so done.
But unless there is a real need or it's already done like the Gibbs Sporter,, I'd say leave it in 6.5x54mm,, great cartridge.
Reload it if you are going for specific performance. Factory ammo is still loaded for it.
The action was made to feed the long 160gr bullet.
The 6.5x53R was chambered in the Dutch, Romanian service rifles and even in a short run of the same Steyr actioned service rifles for the Portuguese Navy.
Holland was licensed to make the rifles for their country and those are marked 'Hembrug' for the arsenal where built.
Steyr 5rd enbloc packet feed. Empty 'clip' drops from the bottom of the magazine when the last round is chambered. Many sporters employ a 'door' on the bottom of the magazine to hold the empty clip for removal by the shooter. They are getting expensive. They are reusable infinetly if not abused. Same system used on the GEW88 and it's sporters,,different enbloc clip though.
Lots of these rifles and carbines as X military were built into very nice sporters both in Europe and Britain. The English admired the orig caliber calling it a .256. They also were fond of converting the rifle*s to 303Brit and 375 N/E 2 1/4"
Cases can be made from a number of common brass. I make them from 303Brit. I used to make them from 30Krag but that stuff is getting to be gold. 303 I have plenty of.
I use regular 6.5x54M/S dies along with a 308 die in the process. INside neck ream as the brass is quite thick after forming. I do that process with a common drill of the .264 size, don't recall which # or letter it is. Works well, very simple.
Standard 264 bullets. I like the 160gr and have an old large stash of pulled FMJ, probably Swede I bought in boxes of 100 for $1/e. Yes it was a while ago. One of those 'you never know when I might need these'.
All this keep a bunch of rifles and carbines in both calibers chugging.
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