35 Mag ????

Have a chance to buy a rifle that is stamped 35 mag on the barrel , even the seller doesnt know exactly what caliber it is .
I managed to find one reference to a 35 magnum on an RCBS caliber list that I found online but not a single other reference anywhere , I'm thinking that its probably a 350 remington mag or maybe a 35 ackley magnum either of which I can find or make ammo for , I'm no stranger to loading for wildcats .
Has anybody heard of or had experience with this vague caliber description before , any information would be much appreciated .

Thats my plan if I get the rifle , also by the bolt face , action length , whether it is belted or not these are all factors which will narrow it down , was just hoping someone had seen the basic marking "35 mag" before.

so what was the actual caliber ? 35 G&H ? the rifle is built on an old american enfield action , so it might well be

ok sounds good , well im going to try and get the rifle and then we will see , fingers crossed

Well I won the rifle, just sent off payment and my local dealers. FFL so just a case of waiting for it to arrive I will update as I have more info

Still ?????

Well I got the rifle today , looking at the chamber it doesnt appear to have a magnum belt but does seem to be a rimmed case , threw a 35 whelan case in to see the fit and it rattles around like a .223 in a 30-06 chamber so whatever it is its huge !! I have ordered a pack of cerrosafe so that I can do an accurate chamber casting and take measurements , this is gonna be fun

just doing some rough sizing the rim measures about the same as a .303 british at .053-.054 overall case length is about 2.70-2.71 base to shoulder is approx 2.25-2.30 diameter at base approx .50 bore diameter at muzzle is .35 .

Obviously I will get much better measurements once I have a casting , but until then if anyone has a book on old cartridges that they could find something close it would be really appreciated .
Its about the size of a 350 no2 rigby , but if it is that why is it stamped 35 mag. ?

Now have a stick of cerrosafe so will hopefully do a chamber cast tonight

After the cast

OK so i did a chamber cast ....

What I have is as follows ;

neck .391 dia by .422 length
shoulder .498 dia
base .514 dia
mag belt .535 dia
main body length 2.16 from bottom of shoulder to top of belt
case overall length 2.85 approx from case mouth to guessed base, rimmed part sits outside of chamber so was not cast

The closest I can find to these dimensions is the .358 STA (shooting times alaskan)

Only problems that I have with that is that this is an old gun and the STA was developed in 1992 plus why was it not marked that caliber ? so anyone have any more ideas ?
Im pretty sure its not the G&H the shoulders too broad and its too long to be a norma or remington magnum did weatherby make a .35 magnum ? case dimensions are the same except the neck for the .375 weatherby mag... if anyones got a spare case or loaded cartridge from an STA that they are willing to part with for me to check against it would be appreciated I would of course return it after the measuring process if needed , I know these big cartridges are not cheap or easy to come by .
all in all im still not 100% sure .

heres a scan of the cast with a 7mm mag. a 35 whelan and a 30-06 as comparison

case length on a .350 rem mag is 2.17 , overall cartridge length including the bullet is 2.80..... just the case on this is as long as the entire loaded cartridge on a rem mag , I did a little more than guess the rim protrusion I measured the length of the 7mm rem mag rim from the belt and added that to my case length , bolt face is the same as a 7mm rem mag .

after doing some more research I have found that the A square company makes 358 STA on enfield 1917 conversions , this one doesnt look like any of their current offerings but it could be an early one or a customer special its completely glass bedded like theirs and the case looks identical , ill contact them and see if they ever marked their barrels in this way .

heres the rifle