Regardless of what a lot of folks are writing, I wouldn't use the small rifle primers. I've tried ... and there are issues. There are pressure and velocity issues, so depending on your adversity to risk you may or may not want to move forward from that. I figured the increased pressure wasn't an issue for the firearms I'd be using. I created 1000 rounds with identical loads but 500 with S&B SRP and 500 with Dominion SRP. The Dominion SRP worked better in my handguns than the S&B. For example -- my M&P would only shoot about 50% of the S&B but shot about 75-80% of the Dominion. The only pistol I tried that was able to fire them without any issues was my Beretta 92A1. My SIG P226 was 100% with the Dominion and about 95% with the S&B. Other guns I tried, from best to worst, Walther PPQ, M&P, Jericho, and Glock 19. The Glock 19, an otherwise totally reliable gun, shot maybe 70-75% of the Dominion but only 20-30% of the S&B loaded rounds.
I understand that your mileage may vary ... but I thought I'd let you know how it worked out for me.