I have been using the Kent Elite Low Recoil/Training loads for a few years now and think they are fantastic. The 3/4 oz. is in a true 2.5" case.
I've gone through around 20 cases and I have had no troubles breaking targets at any range I care to shoot at. I use them in all my vintage guns without hesitation.
RST isn't the only game in town.

https://kentcartridge.com/us/shotshell/elite-low-recoil-training