[North East Redneck]

Had the same problem. Try Treso nipples and #10 Remington caps. These are slightly larger in diameter and seat much better than CCI #11 which are smaller.
I have tried CCI# 10, way too small, CCI # 11 may work, but are VERY tight. The #10 Remis go on the nipples very easy and they don't normally come off under recoil. Good luck. Took me a while to figure mine out, I also came on here and asked many questions. Good people here. Hope this helps.