I've got a nice BRNO 21 action that was worked on by Ralf Martini.

Have heard I can do a 9.3x62 on a small ring, think that could be an interesting project to kick off with a gunmaker like Duane Wiebe or Joe Smithson.

With that said, could I safely go to a bigger cartridge with the 21?

Thanks

You should at least be able to go to any belted mag. The BRNO 21 is basically a commercial version of the G33/40. I know a retired gunmaker who is on his second 257 Weatherby barrel, after shooting out the first one. He did not have the action heat treated/carburizes and he has had absolutely no setback in the lug recesses. I would at least have the hardness checked though, if going to anything stouter than an 06', pressure wise. That would include 270 WCF, as it runs at magnum pressure. However, any of the BRNO 21 and 22's should be good to go, as is.

You have probably heard/read this before, but the wonderful thing about small ring 98's is their ability to have a little narrower stock and thinner barrel at the shank. The weight difference in the action isn't all that much compared to a large ring. You save weight and width in the stock and the barrel. I have a barreled Mexican 1910 in 9.3x62 that has been seasoning in my closet for a couple years. It has a 22" stainless Mauser "Type A" contour barrel. Not exactly light, but you don't want it too light, as the 9.3x62 doesn't kick like a 7x57. It's going to get one of Wayne Yorks layup synthetic stocks, and cerakoted one of these days. I intend for it to be a dark woods thumper in Elk territory. It shouldn't weigh more than 6.5 to 7lbs when completed. Another small ring 9.3x62 project I envision is a wood and blued steel "pencil rifle", built in the style of typical pre-war Guild guns. Another open sight rifle that points like good English bird gun. The Mexican:



BTW, fellow AR member DPCD put this together. He turned and welded on the bolt handle, profiled, chambered, and installed the MRC SS barrel, and slapped on the Willims and NECG sights. Duane Wiebe provided the 06' bottom metal with the front guard screw hole drilled back to fit Mexican mausers.

Sounds like a good candidate for a 400 Whelan.

Colorado, that is a beauty. Thinking 9.3x62 but wondering if I could get anything with more horsepower in it - think .375 is not an option?

I think it might be an option, but I wouldn't consider doing any of the 3.6" magnums without consulting someone like Duane Wiebe, D'Arcy Echols, or the like. The integral front square bridge should actually make the 21 about as strong as a large ring 98. You and your gunmaker will want to strongly consider the possible consequences inherent in heavy kickers if you want to try to go pretty thin with the stock along the action. Things like putting a recoil lug on the bottom of the barrel, installing cross bolts, and carefully selecting a proper stock blank are things to consider.

I've got a 458 winmag on a mexican mauser (yes, the small ring) -

a 9,3x62 would be fine, if you can get it to feed correctly. I'd be worried about length. Though if length isn't an issue, for that action, i'd be really hard pressed not to go 7x64 (or 280) with a fast twist barrel

I also have a 376 steyr on a mexican mauser .. and THAT is a perfect combo

I went with an 06' magazine on the mex on Jeff's recommendation.

I would stay with the 06 case in a 21, but the 9.3x62 is close enough..I built a 7x57---9.3x62 switch barrel custom off a Brno mod. 21 and maintained the stock design and both barrels were mod. 21 Brno barrels, the 9.3 was re-bored from a 8x57 shot out 21 barrel...Made a super nice gun, I built it for myself, but it sold for more money than I could turn down..

I don't think Id do a magnum case on a small ring, not saying it wouldn't work but I wouldn't be comfortable with it..Besides the small ring bespeaks, mid size cartridges IMO..

I bought a worn out Brno mod. 21 right here on AR classified. It had a nice 7x57 barrel, broken stock and an extra 8x57 ruined barrel, perfect for a project..What was amazing both barrels were exact in dimension, and the stock glued back together for a pattern stock, for a high dollar piece of wood I had on hand..It was an edeal combo of calibers..