As mentioned, 8lbs DA is about the limit of reliability with on an otherwise stock S&W. There's some float in that number, and given that CCI primers are relatively hard, I'm not surprised that your gun is one that's having trouble with CCIs at 8lbs. At this point, I think your options are...
1. Set it to 9 lbs. After a bunch of dry fire (which you should be doing anyway), that 9lbs won't likely be much of a handicap relative to an 8lb pull.
2. Have a pro who knows who to tune competition S&Ws do a complete action job on it.
Apex Tactical has been the go-to tuner for many competitive wheelgunners, though they're were in such demand, they had a backlog. There are others, though.
3. Beg, borrow or steal softer primers.
4. Install an
extended firing pin. The Apex pin comes with a lighter FP return spring. This would be the next thing I'd try if you don't want to go down #s 1-3 just yet.
5. Convert to DAO by installing a bobbed hammer. All else being equal, a lighter hammer travels faster and imparts a more powerful primer strike, so converting to DAO enhances reliability a bit. The lighter/faster hammer also has less muzzle-jarring momentum, so you get a bit of an accuracy boost. You can bob the hammer that's on the gun, buy & bob
a replacement, or buy a
hammer from Apex. Apex makes a great hammer, but I'd recommend buying & bobbing the replacement assembly from Midway - it's cheaper, you can bob it as aggressively as you like (make sure your gun is still conforms to any equipment rules set by your sanctioning body, though), and, as a MIM assembly, it's likely a drop-in assembly (unlike the Apex, which will likely require some fitting of the sear).
I can't say for certain, but my hunch is that unless there's something out of alignment inside the gun, the combination of a bobbed hammer (get rid of as much mass as possible and/or allowed) and an Apex pin/spring would light off CCI primers with an 8lb pull.