270 Remington brass is SAAMI registered at an average peak of 65,000 psi, but it can't do it with manufacturing variations in ammo and variations in guns. The primers will fall out.
38 Special brass is SAAMI registered at 17,000 psi peak average and 18,500 psi peak average pressure for +P.
But any 38 special brass I have seen is much stronger than any .270 Win brass. I have never seen any antique balloon brass for 38's but it might be out there.
I have taken handloads to the limit to see what happens in:
.223, .243,25acp, .243Win, 257 Roberts AI, , 270, 32acp, 32sw, 32S&WLong, 32-20, 30 Mauser, 7.62x25mm, .308, 30-06, 7.62x39mm,
7.62x54R, 8x57mm, .380, 9x19mm, 9x23mm, 357 Sig, 38special, 357 mag, 38sw, 40sw, 10mm, 10.4mm, 45acp, 45Colt, .410, and 45/70.
Generally, a small pistol magnum primer replacing a small pistol primer adds the equivalent of 1.1 gr of pistol powder in peak pressure.
It does not add the equivalent of 1.1 gr of pistol powder in velocity. It adds much less than that. So I do not switch out to magnum small pistol primers unless I need them for their added thickness.
I have blown (3) 38 specials into pieces and really damaged another (2).
The term "work up" does not mean as much in 38 special. One can still split the cylinder and break the top strap in a "Work up" before the brass gets too sticky to pull out with some revolvers and some loads.
This means that if the gun is not stronger than the brass, you have to stick with published loads.
What does it all mean?
If you want to load small magnum primers in a 38 special, any 38 special brass is good enough. Use 1.1 gr less powder than your standard load.
If you are using a 357 magnum, then look for the sticky brass that does not want to come out as the real limit. The max pressure for 357 mag was reduced when thinner wall revolvers came out that stretched out the brass into stickiness too easily. The 357 mag brass has a thicker case head for less volume but longer length that crimps into the canalure for very slightly more powder volume than the 38 special brass.