The RIA glock conversion striker spring doesn't have enough juice to ignite a small rifle primer. I'm guessing I'll run into the same issue if I switch to a small pistol magnum primer.
I'm considering an aftermarket spring for the striker assembly, assuming they used Glock parts (which they didn't stick with as far as the sights go, they're 1911 syle)
There are some aspects of this upper assembly that aren't very well though out. The non-captured RSA is one of them, the sights another, the striker spring a third, and I recently found that once the barrel gets warm, factory ammo won't extract, double feed every time. Customer service isn't exactly stellar, either.
Let me know if any of you all have had luck with some sort of hotter, softer cupped primers to light the H110. I've seen what happens when that stuff doesn't burn and it turns into dried out caramel in revolver cylinders, and I'd like to avoid that here, or I may just start experimenting with AA9, 2400, something along those lines. TCM powder is basically for 357s, and I've heard MP-300 works in the load as well, so maybe that's going to be my next route. I don't really see the TCM powder lasting on the market, only places it's available are online.